- Email: [email protected]
Physicochemical and structural properties of starches isolated from quinoa varieties
Journal Pre-proof Physicochemical and structural properties of starches isolated from quinoa varieties Fan Jiang, Chunwei Du, Ying Guo, Jiayang Fu, Wenqian Jiang, Shuang-kui Du PII:
S0268-005X(19)31347-5
DOI:
https://doi.org/10.1016/j.foodhyd.2019.105515
Reference:
FOOHYD 105515
To appear in:
Food Hydrocolloids
Received Date: 19 June 2019 Revised Date:
12 November 2019
Accepted Date: 12 November 2019
Please cite this article as: Jiang, F., Du, C., Guo, Y., Fu, J., Jiang, W., Du, S.-k., Physicochemical and structural properties of starches isolated from quinoa varieties, Food Hydrocolloids (2019), doi: https:// doi.org/10.1016/j.foodhyd.2019.105515. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.
Physicochemical Quinoa (Chenopodium quinoa Willd.) seeds
properties
Isolation Pasting properties
Rheological properties
Relationship
Quinoa starch
Structural properties Morphology
Crystalline properties
1
Physicochemical and structural properties of starches
2
isolated from quinoa varieties
3
Fan Jianga, Chunwei Dua, Ying Guoa, Jiayang Fua, Wenqian Jianga, Shuang-kui Dua*
4
a
5
712100, China
6
* Corresponding author. E-mail: [email protected](Sh-K. Du)
7
Tel: 86-29-87092206; Fax: 86-29-87092486;
8
9
10
11
12
13
14
15
16
17
College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi
18
19
20
21
22
Abstract
23
Starches isolated from four quinoa varieties were analyzed for physicochemical,
24
morphological, and structural properties. All varieties of quinoa starches (QS) have
25
lower amylose content, ranging from 9.43% to 10.90%, than maize starch (22.58%)
26
and potato starch (17.75%) and thus has lower water solubility index and higher
27
swelling power. QS has lower pasting temperature and setback and breakdown than
28
maize starch. QS has lower enthalpy change (△H) and exhibits good resistance to
29
retrogradation. In terms of rheological properties, QS has lower degree of
30
shear-thinning and thixotropy than maize and potato starch. Additionally, QS has
31
irregular polygon granules with small granule diameters ranging from 1.21 µm to 1.95
32
µm and display the A-type X-ray diffraction pattern. The crystallinity of QS ranges
33
from 21.00% to 29.67%, which is significantly lower than that of maize starch.
34
Fourier-transform infrared spectroscopy showed that the QS structure is a double
35
helix and has a lower degree of order than the structures of maize and potato starch.
36
This study revealed the particular properties of QS with four varieties as compared
37
with other starch varieties.
38
Keywords: Quinoa starch; Structural properties; Pasting; Rheology; Thermal
39
properties
40
41
42
43
44
List of abbreviations
45
QS
quinoa starch
MS
maize starch
PS
potato starch
Q1
Haili quinoa seeds
Q2
Gannan quinoa seeds
Q3
Geermu quinoa seeds
Q4
Jingle quinoa seeds
QS1
Haili quinoa starch
QS2
Gannan quinoa starch
QS3
Geermu quinoa starch
QS4
Jingle quinoa starch
WSI
water solubility index
SP
swelling power
△H
enthalpy of gelatinization
G′
storage modulus
G′′
loss modulus
APS
average particle size
DO
degree of order
DD
degree of the double helix
46
1. Introduction
47
Quinoa (Chenopodium quinoa Willd.) is the main traditional food of the Inca
48
aborigines because of its high tolerance to extreme conditions, such as drought, frost,
49
salinity, and insect damage (Jacobsen, Mujica, & Jensen, 2003; Stikic et al., 2012).
50
Quinoa has huge genetic variability and persists in a wide range of environmental
51
conditions, providing possibility for testing in diverse regions of China, the USA,
52
Canada, India, England, Denmark, Greece, and Italy (Bhargava, Shukla, & Ohri, 2007;
53
Razzaghi et al., 2011). To date, quinoa production is increasing in some parts of China
54
where it grows well. Especially in Gansu, Qinghai and Shanxi regions, where there
55
are different altitudes and rainfall to cultivate different quinoa varieties. In recent
56
years, quinoa has attracted increasing interest worldwide because it has a high
57
nutritional value and does not contain gluten-type protein. It has been widely
58
recognized for its efficacy in preventing obesity, cardiovascular disease, diabetes, and
59
cancer (Escribano et al., 2017; Ferreira, Pallone, & Poppi, 2015; Navruz-Varli &
60
Sanlier, 2016).
61
Starch is the main nutrient component of many food substrates and plays an
62
important role in the functional and nutritional properties of processed foods
63
(Perez-Pacheco et al., 2014). Starch is the major component of quinoa grains,
64
accounting for 58% - 64% of the content of a quinoa grains. Amylose content in the
65
grains ranges from 4% to 25% (Qian & Kuhn, 1999; Watanabe, Peng, Tang, &
66
Mitsunaga, 2007). Previous studies showed that quinoa amylopectin had significant
67
amounts of short chains and super long chains (Li & Zhu, 2017a). Amylopectin chain
68
profile and amylose content affect the physicochemical and functional properties of
69
quinoa starch (QS). The starch granules of quinoa are irregular polygons ranging in
70
diameter from 1 µm to 3 µm, and have lower crystallinity than maize starch granules
71
(Ruales & Nair, 1994). QS exhibits higher water solubility index (WSI) and swelling
72
power (SP) than wheat and barley starch and highly susceptibility to enzyme (Tang,
73
Watanabe, & Mitsunaga, 2002). Moreover, QS has lower pasting temperature and
74
peak viscosity than normal maize starch and is far preferable to other starch varieties
75
as a thickening agent for fillings (Nienke Lindeboom, Chang, Falk, & Tyler, 2005;
76
Lorenz, 2010). In addition, QS is used in active food packaging to maintain food
77
safety and extend the shelf life of packaged food (Pagno et al., 2015).
78
Quinoa seeds from different regions also have a certain effect on its starch
79
quality. And the relationship between the physicochemical and structural properties of
80
QS is uncertain. In this work, the starches of four quinoa varieties from different
81
regions were determined the physicochemical and structural properties. The properties
82
of the starches were compared with those of maize starch and potato starch. The
83
systematic analysis of QS properties would provide basis for its development and
84
utilization.
85
2. Materials and methods
86
2.1 Materials
87
Four quinoa seeds were Haili quinoa (Q1) and Gannan quinoa (Q2) obtained
88
from the arid area and cold damp area with the altitude of 2000m - 4920m in Gansu,
89
Geermu quinoa (Q3) obtained the valley area with the altitude of 2300m in Qinghai,
90
Jingle quinoa (Q4) obtained from the barren soil area with the altitude of 1500m in
91
Shanxi. The seeds were then cultivated at the experimental open farm of Agricultural
92
Technology Promotion Center of Shenmu in Yulin. According to the wet milling
93
method reported by Ji, Seetharaman, and White (2004), QS was isolated from these
94
varieties and labeled QS1, QS2, QS3 and QS4. Normal maize starch (MS) and potato
95
starch (PS) were purchased from Aladdin Reagent Co., Ltd. (Shanghai, China). All the
96
chemicals used were of reagent grade.
97
2.2 Proximate composition
98
The crude protein content (PC%), lipid content (LC%), and ash content (AC%)
99
were determined in accordance with the method of AOAC (2005). A total starch assay
100
kit (Megazyme International Ireland Ltd., Ireland) was used to determine total starch
101
content (TS%). Amylose content (AC%) in the starch samples was determined by
102
using the iodine colorimetric determination, the method was described by Morrison
103
and Laignelet (1983) with some modification by Jan et al. (2017).
104
2.3 Physicochemical properties
105
2.3.1 Water solubility index (WSI) and swelling power (SP)
106
WSI (%) and SP (g/g) were determined according to the method of Tsai, Li, and
107
Lif (1997) with some modifications. Starch suspension of 1% was transferred to
108
centrifuge tubes and placed on a vortex mixer for 10 s. The samples were then heated
109
from 55 ℃ to 95 ℃ (at 10 ℃ intervals) for 30 min at thermostatic oscillating water
110
bath and then cooled to room temperature and centrifuged (3500 rpm, 15 min). The
111
supernatant was poured into a preweighed aluminum box to a constant weight (Ws) at
112
105 ℃. The remaining sediment paste was weighed (Wr) immediately. All
113
measurements were conducted in triplicates. The WSI (%) and SP (g/g) were
114
calculated. W WSI (%) = S ×100 W0
115
SP(g/g ) =
116
117
Wr W0 × (100 − WSI )
2.3.2 Pasting analysis
118
Pasting properties of starches were determined with a rapid visco-analyzer
119
(Perten, TechMastet, Sweden). The method described by Du et al. (2014) was used.
120
The main viscosity parameters were measured from the pasting curves using with
121
instrument software.
122
2.3.3 Thermal analysis
123
The thermal properties of starch were analyzed by using a differential scanning
124
calorimeter (Waters, Q2000, American) and through the method described by Ma et
125
al. (2017). The sealed crucibles were heated from 10 ℃ to 100 ℃ at a rate of 10 ℃/min.
126
The tested samples were placed at 4 ℃ for 7 days after the experiments. The
127
properties of retrogradation were determined by the same method.
128
2.3.4 Rheological analysis
129
The rheological properties of the starches were measured with TA Instruments
130
rheometer (TA Instruments, DHR-1, USA). The rheometer was employed with a 40
131
mm parallel plate geometry and a Peltier plate. After gelatinization, the 5% starch
132
suspension was placed between the parallel plate and Peltier plate with a gap of 1000
133
µm. The rheological parameters were obtained by using the producer of Steady State
134
Flow and OsciLLation.
135
2.4 Scanning electron microscopy
136
The morphological properties of the native starches were measured with a
137
scanning electron microscope (FEI, Nova Nano SEM-450, America).
138
2.5 Particle size analysis
139
The starch granules were suspended in water fully dispersed in an ultrasonic
140
oscillator. The particle size distribution was obtained by a laser diffraction particle
141
size analyzer (MALVERN, ZEN3600, England).
142
2.6 X-ray diffraction
143
X-ray analysis was performed with an X-ray diffractometer (Bruker, D8
144
ADVANCE A25, Germany) with a target Cu-anode X-ray tube. The scanning region
145
of the diffraction angle (2θ) was from 5° to 45° with a scanning step of 0.02° and
146
scanning speed of 6°/min. The crystallinity of each starch variety was calculated by
147
using Jade 6.5 software.
148
2.7 Fourier transformed infrared spectrometry (FTIR)
149
FTIR analysis was preformed with a Fourier transform infrared spectrometer
150
(Bruker, Vetex70, Germany) and through the method of Zeng et al. (2015) with minor
151
modifications. The samples were mingled with dried potassium bromide (1:100, v/v)
152
by an agate mortar. The mixed powder was placed into a vacuum compression and
153
pressured into a sheet. The spectra, recorded against a potassium bromide flake as the
154
background, were set from 400 cm-1 to 4000 cm-1, and the resolution was 4 cm-1.
155
Scanning was performed 16 times.
156
2.8 Statistical analysis
157
All measurements were in performed in triplicate. Data were analyzed with SPSS
158
software (IBM Corporation, NY, USA ). The significant differences were obtained by
159
analysis of variance (ANOVA) followed by Duncan’s multiple range test (P<0.05).
160
3. Results and discussion
161
3.1 Proximate composition
162
The proximate compositions of the four QS varieties, MS and PS samples are
163
listed in Table 1. The total starch content of QS ranged from 91.65% (QS4) to 95.30%
164
(QS3). The protein, lipid, and ash contents of the samples were relatively low,
165
indicating that the samples met the experimental requirements in the absence of
166
nonstarch lipids and hydrated fine fibers (Zhou, 2004; Jan, Panesar, Rana, & Singh,
167
2017). The amylose content of QS ranged from 9.43% in QS3 to 10.90% in QS1 and
168
was significantly lower than the amylose contents of MS (22.58%) and PS (17.75%).
169
This result is in the range of the values (0.3%-12.1%) reported by Lindeboom et al.
170
(2005). QS with low amylose content could contain large amounts of amylopectin and
171
thus cannot be easily retrograded.
172
3.2 Physicochemical properties
173
3.2.1 WSI and SP
174
The WSI and SP of the isolated QS, along with those of PS and MS, are
175
presented in Fig. 1(a) and (b). The WSI and SP values of the starches increased with
176
temperature. In the QS varieties, the maximum WSI and SP values were obtained in
177
QS2 (17.57 % and 28.15 g/g, respectively), and the minimum values in QS4 (6.45 %
178
and 21.83 g/g, respectively). The SP values of all the QS were significantly lower than
179
the SP of PS, thus, QS granules could well maintain their integrity under the
180
gelatinization temperature. However, the SP of QS was slightly higher than that of
181
MS, possibly because the QS particles were small and easy to interact with water
182
molecules. QS showed higher SP and lower WSI than MS. This condition could be
183
related to the low amylose content of QS because amylose restricts granule swelling
184
by reinforcing the internal network (Tang et al., 2002). The differences in WSI among
185
the starches may be due to the variations among their chain length distributions.
186
Additionally, QS amylopectin has significant amounts of short chains and super long
187
chains (Li & Zhu, 2018a).
188
3.2.2 Pasting properties
189
The pasting properties of starches are summarized in Table 2. Significant
190
differences (P<0.05) in pasting properties among starches were observed. No
191
differences in pasting temperature (PT) were observed among the four QS varieties.
192
The lowest peak viscosity (PV) and setback (SB) and the highest breakdown (BD) of
193
QS3 may be due to its the lowest amylose content (Table1). The PT of QS ranged
194
from 72.60℃ to 72.63℃ and was higher than that of PS (67.90℃) and lower than that
195
of MS (75.93℃). These higher PT values indicated that starches are difficult to swell
196
and rupture (Du et al., 2014). The PV of QS (2983-3551 cP) was higher than MS
197
(2669 cP) and lower than PS (4144 cP). This trend was consistent with SP discussed
198
above (Fig.1(a)). High PV values are associated with the high degree of granule
199
swelling or water binding capacity of starches (Osundahunsi, Fagbemi, Kesselman, &
200
Shimoni, 2003). The low BD of QS indicated that this paste had the stronger shear
201
resistance. The SB of QS ranged from 442 cP (QS3) to 730 cP (QS1) and was much
202
lower than that of MS (1172 cP). This is related to the low amylose content of QS
203
(Table 1). The values of QS pasting parameters were almost accordant to the values
204
obtained in the previous study (Steffolani, León, & Pérez, 2013). The relatively low
205
BD and SD and high PV of QS suggested that this starch has low hardness,
206
gumminess, chewiness, and high adhesiveness to provide particular texture and
207
application (Wu, Morris, & Murphy, 2014).
208
3.2.3 Thermal properties
209
The starch gelatinization transition temperatures (onset, To; peak, Tp; and
210
conclusion, Tc), gelatinization temperature range (△T) along with enthalpy of
211
gelatinization (△H, △H'), and retrogradation ratio (R) are summarized in Table 2. QS
212
had lower To, Tp, and Tc than MS but the values are close to those of PS, since QS had
213
low crystallinity and its granules were easy to gelatinize. The differences in
214
gelatinization temperature may be influenced by the branch-chain length of
215
amylopectin, the amylose content, and the presence of endogenous components, such
216
as lipids and proteins (Hoover, Hughes, Chung, & Liu, 2010; Nadjemi & Deroanne,
217
2009). QS had a wide △T especially in QS2 as compared with MS and PS, and QS4
218
had the lowest △H. This result may reflect that QS has a wide range of crystal
219
stability and longer branch chains in its amylopectin content than the control
220
(Fredriksson, Silverio, Andersson, Eliasson, & Aman, 1998). The To, Tp, Tc, and △H
221
of QS were higher than the values reported by Fuentes et al. (2019)，and by Jan et al.
222
(2017). This result might be due to the different genotypes of quinoa seeds from
223
different geographical locations. QS were not present in retrogradation after 7 days at
224
4 ℃ compared with MS (32.07%) and PS (28.69%), suggesting that QS had a great
225
amount of amylopectin with long branch chains to resist retrogradation. The long
226
branch chains of amylopectin have the high degree of polymerization. The orientation
227
arrangement of long branch chains is harder than short chain, which reduce the
228
recrystallization rate of starch so that starch can resist to retrogradation (Hoover,
229
Hughes, Chung, & Liu, 2010). The amylopectin structure of QS has an important role
230
in its thermal properties.
231
3.2.4 Rheological properties
232
The Herschel-Bulkley (τ=τ0 + Kγn) mathematical model was used to fit the
233
starch paste based on the relationship between shear stress and shear rate. This model
234
described well the different starch gel systems even at low shear rates (Li & Zhu,
235
2017). The flow characteristic index (n) of this model ranged from 0.65 to 0.92 (Table
236
2), reflecting the pseudoplastic characteristics (n<1) of the QS paste. This QS paste
237
property is in accordance with the Not-Newton fluidity law and has a different degree
238
of thixotropy. The flow curves of starch pastes from different cultivars exhibited lag
239
rings, which areas are positively correlated with thixotropy (Kong, Kasapis, Bertoft,
240
& Corke, 2010). The mean lag ring areas of the starches had the following order:
241
QS1 > QS4 > QS2 > QS3 (Table 2). The experimental results were possibly affected
242
by the content of amylose and internal chain structure of amylopectin (Wang et al.,
243
2010). The phenomenon of increasing shear force and decreasing apparent viscosity
244
revealed that QS paste could be considered as a shear-thinning system (Fig.1(c)). The
245
shear-thinning phenomenon in QS3 was the most obvious but lower in extent than
246
that in MS and PS possibly because of the low amylose content of QS. These results
247
are in accordance with previous reports (Ahmed, Thomas, Arfat, & Joseph, 2018).
248
In general, frequency scanning has been used widely to provide further insights
249
into the dynamic rheological behavior of materials (Kong et al., 2010). The storage
250
modulus (G′) and loss modulus (G′′) of all kinds of starch pastes increased steadily
251
during frequency scanning range. G′ was obviously higher than G″ within the
252
frequency scanning range, and no crossing was observed between them, except in the
253
PS paste (Fig. 1(d) and (e)). The result showed that the gel strength of QS and MS
254
were stronger than PS throughout the frequency range mostly due to the reordering of
255
leached amylose. The amylose fixed by hydrogen bonds during cooling can restrict
256
the molecules or particles from moving (Li & Zhu, 2018b). The high G′ represents a
257
solid and elastic gel network structure and with high degrees of cross-linking (Ai &
258
Jane, 2015). Previous research showed that the internal structure of QS with super
259
long chain fractions of amylopectin may play an important role in the rheological
260
properties (Li & Zhu, 2018b).
261
3.3 Morphological properties
262
The scanning electron microscopy micrographs of the starch granules are shown
263
in Fig. 2. The four QS varieties showed similar granular polygons and irregularity,
264
which were the same with those of MS granules but different from those of PS
265
granules. Compared with MS and PS, the surface of QS granules appeared to be rough
266
but with no fissure (Fig. 2). The granule morphology agreed with the previous reports
267
in starches from different quinoa varieties (Lindeboom, Chang, Tyler, & Chibbar,
268
2005; Tang et al., 2002).
269
Size distributions of the starch granules are presented in Table 4. The average
270
particle size of the QS ranged from 1.21 µm (QS2) to 1.95 µm (QS3). These values
271
were significantly smaller than those of MS (14.20 µm) and PS (44.65 µm). QS
272
presented a wide size distribution because they formed aggregated structures, which
273
are typical of most starches consisting of small granules (Qian & Kuhn, 1999).
274
Similar results were observed by Steffolani et al. (2013). Starch granule and particle
275
size distribution may affect physicochemical properties, such as solubility, pasting,
276
and enzyme susceptibility. Starch granules from different botanical origins differ in
277
size and shape with various genotype and growing conditions (Hoover & Sosulski,
278
1991).
279
3.4 X-ray diffraction
280
X-ray diffractometry was used to evaluate the characteristics of the crystalline
281
structure of starch granules. The diffraction peaks of QS and MS appeared near 15°,
282
17° and 23°. All the QS varieties showed the A-type crystalline arrangement patterns,
283
which are common to cereal starches. Meanwhile, PS showed the B-type crystalline
284
pattern with diffraction peaks near 17°, 19°, 22° and 24° (Fig. 3(a)). This result is
285
consistent with previous reported results (Ahmed et al., 2018). The degree of
286
crystallinity of QS ranging from 21.00% in QS1 to 29.67% in QS3 was lower than
287
that in MS in 36.05%. However, the values were close to PS with 25.68% (Table 4).
288
The crystallinity for QS presented here was lower than the results reported by
289
Steffolani et al. (2013). The chemical structure, especially the chain length
290
distribution of amylopectin and composition of starches, may affect such differences
291
among starches (Zobel, 2010). As previously reported, QS had a significantly large
292
number of A-chains with fingerprint structure, which led to a low degree of
293
crystallinity (Li & Zhu, 2018a). The crystalline regions are related to the structure and
294
content of amylopectin molecules, whereas the amorphous regions are related to
295
amylose molecules (Zobel, 1998). The crystallinity of four QS was negatively
296
correlated with the amylose content, showing that QS1 had low crystallinity with high
297
amylose content.
298
3.5 Fourier transform infrared spectrometer
299
FTIR analysis technique was used to reflect the short-range ordered structure of
300
starch as the order of double helix structure of starch. The FTIR spectra of the starch
301
samples are illustrated in Fig. 3(b). No difference was observed in the detected peaks
302
of four QS varieties, indicating no difference in the chemical groups among the QS
303
varieties. The spectrum was characterized by three typical absorption peaks with
304
maximum absorbance at 995, 1022, and 1047 cm-1. These values can well reflect the
305
crystalline properties of starch granules (López-Barón et al., 2018). The intensity ratio
306
at 1047/1022 cm-1 could reflect the degree of order (DO), and the intensity ratio at
307
995/1022 cm-1 characterized the degree of the double helix (DD) (Zeng et al., 2015).
308
The DO values of QS ranging from 0.698 in QS1 to 0.762 in QS3 were lower than
309
that in MS of 0.883 and PS of 0.826 (Table 4). A positive correlation was observed
310
between the DO and starch crystallinity, indicating that the crystalline structure was
311
formed by orderly starch chains. The DD values of QS ranged from 0.515 to 0.560,
312
which were generally lower than those of MS (0.998) and PS (1.012). The results
313
were similar to the results reported previously by Jasim Ahmed (Ahmed et al., 2018),
314
suggesting that QS has a lower number of double helix structure than MS and PS. The
315
lower number of double helix structure resulted in lower △H of QS (Table 3). The
316
differences in results among the starches could be attributed to the biological origin,
317
the contents of amylose and amylopectin, and the amylopectin molecular structure (Li
318
& Zhu, 2017b).
319
4. Conclusion
320
Isolated starches from four quinoa samples, maize, and potato showed
321
variation in physicochemical and morphological structure. QS had lower amylose
322
content and thus had lower WSI and higher SP. QS exhibited lower PT and SB and
323
BD than MS, indicating it had the stronger shear resistance. QS with long branch
324
chains had the widest range of △T and lowest △H among the starches, revealing that
325
QS has good resistance to retrogradation. Moreover, QS had the lowest degree of
326
shear thinning and thixotropy, and QS1 had the highest G′ and G′′. These results may
327
indicate that QS are suitable for industrial production. QS morphology was irregular
328
polygon, had small granule diameter (1.21 µm-1.95 µm), showed the A-type X-ray
329
diffraction pattern, and had a crystallinity of 21.00%-29.67%, which was significantly
330
lower than that of MS. The lowest degree of order and double helix of QS structure
331
were compared with those of MS and PS. The influence of amylopectin on QS
332
properties remains to be explored. These properties may provide basis for the
333
utilization of QS in various applications.
334
Acknowledgements
335
The authors would like to thank Shaanxi Province Key Research and
336
Development Program Project (2017NY-177) and Shaanxi Province Agricultural
337
Science and Technology Innovation and Transformation Project (NYKJ-2018-YL19)
338
for the support.
339
References
340
AOAC. (2005). Official methods of analysis of AOAC International 18th edn. AOAC
341
International, Gaithersberg. https://doi.org/10.1016/0924-2244(95)90022-5.
342
Ahmed, J., Thomas, L., Arfat, Y. A., & Joseph, A. (2018). Rheological, structural and
343
functional properties of high-pressure treated quinoa starch in dispersions.
344
Carbohydrate Polymers, 197, 649-657.
345
https://doi.org/10.1016/j.carbpol.2018.05.081.
346 347
Ai, Y., & Jane, J.-l. (2015). Gelatinization and rheological properties of starch. Starch - Stärke, 67(3-4), 213-224. https://doi.org/10.1002/star.201400201.
348
Bhargava, A., Shukla, S., & Ohri, D. (2007). Genetic variability and interrelationship
349
among various morphological and quality traits in quinoa (Chenopodium
350
quinoa
351
https://doi.org/10.1016/j.fcr.2006.10.001.
Willd.).
Field
Crops
Research,
101(1),
104-116.
352
Du, S. K., Jiang, H., Ai, Y., & Jane, J. L. (2014). Physicochemical properties and
353
digestibility of common bean (Phaseolus vulgaris L.) starches. Carbohydrate
354
Polymers, 108, 200-205. https://doi.org/10.1016/j.carbpol.2014.03.004.
355
Escribano,
J.,
Cabanes,
J.,
Jimenez-Atienzar,
M.,
Ibanez-Tremolada,
M.,
356
Gomez-Pando, L. R., Garcia-Carmona, F., & Gandia-Herrero, F. (2017).
357
Characterization of betalains, saponins and antioxidant power in differently
358
colored quinoa (Chenopodium quinoa) varieties. Food Chemistry, 234,
359
285-294. https://doi.org/10.1016/j.foodchem.2017.04.187.
360
Ferreira, D. S., Pallone, J. A. L., & Poppi, R. J. (2015). Direct analysis of the main
361
chemical constituents in Chenopodium quinoa grain using Fourier transform
362
near-infrared spectroscopy. Food Control, 48, 91-95.
363
https://doi.org/10.1016/j.foodcont.2014.04.016.
364
Fredriksson, H., Silverio, J., Andersson, R., Eliasson, A. C., & Åman, P. (1998). The
365
influence of amylose and amylopectin characteristics on gelatinization and
366
retrogradation properties of different starches. Carbohydrate Polymers,
367
35(3–4), 119-134. https://doi.org/10.1016/S0144-8617(97)00247-6.
368
Hoover, R., Hughes, T., Chung, H. J., & Liu, Q. (2010). Composition, molecular
369
structure, properties, and modification of pulse starches: A review. Food
370
Research International, 43(2), 399-413.
371
https://doi.org/10.1016/j.foodres.2009.09.001.
372
Jacobsen, S. E., Mujica, A., & Jensen, C. R. (2003). The Resistance of Quinoa
373
(Chenopodium quinoa Willd.) to Adverse Abiotic Factors. Food Reviews
374
International, 19(1-2), 99-109. https://doi.org/10.1081/FRI-120018872.
375
Jan, K. N., Panesar, P. S., Rana, J. C., & Singh, S. (2017). Structural, thermal and
376
rheological properties of starches isolated from Indian quinoa varieties.
377
International
378
https://doi.org/10.1016/j.ijbiomac.2017.04.027.
Journal
of
Biological
Macromolecules,
102,
315-322.
379
Ji, Y., Seetharaman, K., & White, P. J. (2004). Optimizing a Small-Scale Corn-Starch
380
Extraction Method for Use in the Laboratory. Cereal Chemistry Journal, 81(1),
381
55-58. https://doi.org/10.1094/CCHEM.2004.81.1.55.
382
Kong, X., Kasapis, S., Bertoft, E., & Corke, H. (2010). Rheological properties of
383
starches from grain amaranth and their relationship to starch structure. Starch -
384
Stärke, 62(6), 302-308. https://doi.org/10.1002/star.200900235.
385 386
Li, D., & Zhu, F. (2017). Physicochemical properties of kiwifruit starch. Food Chemistry, 220, 129-136. https://doi.org/10.1016/j.foodchem.2016.09.192.
387
Li, G., & Zhu, F. (2017a). Amylopectin molecular structure in relation to
388
physicochemical properties of quinoa starch. Carbohydrate Polymers, 164,
389
396-402. https://doi.org/10.1016/j.carbpol.2017.02.014.
390
Li, G., & Zhu, F. (2017b). Molecular structure of quinoa starch. Carbohydrate
391
Polymers, 158, 124-132. https://doi.org/10.1016/j.carbpol.2016.12.001.
392
Li, G., & Zhu, F. (2018a). Quinoa starch: Structure, properties, and applications.
393
Carbohydrate Polymers, 181, 851-861.
394
https://doi.org/10.1016/j.carbpol.2017.11.067.
395
Li, G., & Zhu, F. (2018b). Rheological properties in relation to molecular structure of
396
quinoa starch. International Journal of Biological Macromolecules, 114,
397
767-775. https://doi.org/10.1016/j.ijbiomac.2018.03.039.
398
Lindeboom, N., Chang, P. R., Falk, K. C., & Tyler, R. T. (2005). Characteristics of
399
Starch from Eight Quinoa Lines. Cereal Chemistry, 82(2), 216-222.
400
https://doi.org/10.1094/CC-82-0216.
401
Lindeboom, N., Chang, P. R., Tyler, R. T., & Chibbar, R. N. (2005). Granule-Bound
402
Starch Synthase I (GBSSI) in Quinoa ( Chenopodium quinoa Willd.) and Its
403
Relationship to Amylose Content. Cereal Chemistry, 82(3), 246-250.
404
https://doi.org/10.1094/CC-82-0246.
405
López-Barón, N., Sagnelli, D., Blennow, A., Holse, M., Gao, J., Saaby, L., Vasanthan,
406
T. (2018). Hydrolysed pea proteins mitigate in vitro wheat starch digestibility.
407
Food Hydrocolloids, 79, 117-126.
408
https://doi.org/10.1016/j.foodhyd.2017.12.009.
409
Lorenz, K. (2010). Quinoa (Chenopodium quinoa) starch physico-chemical properties
410
and functional characteristics. Starch - Stärke, 42(3), 81-86.
411
https://doi.org/10.1002/star.19900420302.
412
Ma, M., Wang, Y., Wang, M., Jane, J.-l., & Du, S.-k. (2017). Physicochemical
413
properties and in vitro digestibility of legume starches. Food Hydrocolloids,
414
63, 249-255. https://doi.org/10.1016/j.foodhyd.2016.09.004.
415
Morrison, W. R., & Laignelet, B. (1983). An improved colorimetric procedure for
416
determining apparent and total amylose in cereal and other starches. Journal of
417
Cereal Science, 1(1), 9-20. https://doi.org/10.1016/S0733-5210(83)80004-6.
418
Nadjemi, B., & Deroanne, C. (2009). Physicochemical and functional properties of
419
starches from sorghum cultivated in the Sahara of Algeria. Carbohydrate
420
Polymers, 78(3), 475-480. https://doi.org/10.1016/j.carbpol.2009.05.010.
421
Navruz-Varli, S., & Sanlier, N. (2016). Nutritional and health benefits of quinoa
422
( Chenopodium quinoa Willd.). Journal of Cereal Science, 69, 371-376.
423
424
https://doi.org/10.1016/j.jcs.2016.05.004.
Osundahunsi, O. F., Fagbemi, T. N., Kesselman, E., & Shimoni, E. (2003).
425
Comparison of the physicochemical properties and pasting characteristics of
426
flour and starch from red and white sweet potato cultivars. Journal of
427
Agriculture and Food Chemistry, 51(8), 2232-2236.
428
https://doi.org/10.1021/jf0260139.
429
Pagno, C. H., Costa, T. M., de Menezes, E. W., Benvenutti, E. V., Hertz, P. F., Matte,
430
C. R., Flores, S. H. (2015). Development of active biofilms of quinoa
431
(Chenopodium quinoa W.) starch containing gold nanoparticles and evaluation
432
of antimicrobial activity. Food Chemistry, 173, 755-762.
433
https://doi.org/10.1016/j.foodchem.2014.10.068.
434
Perez-Pacheco, E., Moo-Huchin, V. M., Estrada-Leon, R. J., Ortiz-Fernandez, A.,
435
May-Hernandez, L. H., Rios-Soberanis, C. R., & Betancur-Ancona, D. (2014).
436
Isolation and characterization of starch obtained from Brosimum alicastrum
437
Swarts seeds. Carbohydrate Polymers, 101, 920-927.
438
https://doi.org/10.1016/j.carbpol.2013.10.012.
439
Qian, J., & Kuhn, M. (1999). Characterization of Amaranthus cruentus and
440
Chenopodium quinoa Starch. Starch - Stärke, 51(4), 116–120.
441
https://doi.org/10.1002/(SICI)1521-379X(199904)51:43.0.CO;2-R.
442 443
Razzaghi, F., Ahmadi, S. H., Adolf, V. I., Jensen, C. R., Jacobsen, S. E., & Andersen, M. N. (2011). Water Relations and Transpiration of Quinoa (Chenopodium
444
quinoa Willd.) Under Salinity and Soil Drying. Journal of Agronomy and
445
Crop Science, 197(5), 348-360.
446
https://doi.org/10.1111/j.1439-037X.2011.00473.x.
447
Ruales, J., & Nair, B. M. (1994). Properties of starch and dietary fibre in raw and
448
processed quinoa (Chenopodium quinoa, Willd) seeds. Plant Foods for
449
Human Nutrition, 45(3), 223-246. https://doi.org/10.1007/bf01094092.
450
Steffolani, M. E., León, A. E., & Pérez, G. T. (2013). Study of the physicochemical
451
and functional characterization of quinoa and kañiwa starches. Starch - Stärke,
452
65(11-12), 976-983. https://doi.org/10.1002/star.201200286.
453
Stikic, R., Glamoclija, D., Demin, M., Vucelic-Radovic, B., Jovanovic, Z.,
454
Milojkovic-Opsenica, D., Milovanovic, M. (2012). Agronomical and
455
nutritional evaluation of quinoa seeds (Chenopodium quinoa Willd.) as an
456
ingredient in bread formulations. Journal of Cereal Science, 55(2), 132-138.
457
https://doi.org/10.1016/j.jcs.2011.10.010.
458
Tang, H., Watanabe, K., & Mitsunaga, T. (2002). Characterization of storage starches
459
from quinoa, barley and adzuki seeds. Carbohydrate Polymers, 49(1), 13-22.
460
https://doi.org/10.1016/s0144-8617(01)00292-2.
461
Tsai, M. L., Li, C. F., & Lif, C. Y. (1997). Effects of granular structures on the pasting
462
behaviors of starches. Cereal Chemistry, 74(6), 750-757.
463
https://doi.org/10.1094/CCHEM.1997.74.6.750.
464
Wang, J., Yu, L., Xie, F. W., Chen, L., Li, X. X., & Liu, H. S. (2010). Rheological
465
properties
and
phase
transition
of
cornstarches
with
different
466
amylose/amylopectin ratios under shear stress. Starch - Stärke, 62(12),
467
667-675. https://doi.org/10.1002/star.201000059.
468
Watanabe, K., Peng, N. L., Tang, H., & Mitsunaga, T. (2007). Molecular Structural
469
Characteristics of Quinoa Starch. Food Science & Technology International
470
Tokyo, 13(1), 73-76. https://doi.org/10.3136/fstr.13.73.
471
Wu, G., Morris, C. F., & Murphy, K. M. (2014). Evaluation of texture differences
472
among varieties of cooked quinoa. Journal of Food Science, 79(11),
473
S2337-2345. https://doi.org/10.1111/1750-3841.12672.
474
Zeng, S., Wu, X., Lin, S., Zeng, H., Lu, X., Zhang, Y., & Zheng, B. (2015). Structural
475
characteristics and physicochemical properties of lotus seed resistant starch
476
prepared
477
https://doi.org/10.1016/j.foodchem.2015.03.143.
by
different
methods.
Food
Chemistry,
186,
213-222.
478
Zhou, Y. (2004). Relationship between α-amylase degradation and the structure and
479
physicochemical properties of legume starches. Carbohydrate Polymers, 57(3),
480
299-317. https://doi.org/10.1016/j.carbpol.2004.05.010.
481 482
Zobel, H. F. (2010). Molecules to Granules: A Comprehensive Starch Review. Starch - Stärke, 40(2), 44-50. https://doi.org/10.1002/star.19880400203.
483
Figure captions:
484
Fig. 1. (a) Water solubility index and (b) swelling power of starches; (c) Apparent
485
viscosity plot against shear rate; (d) Storage modulus and loss modulus (e) of
486
frequency sweep profiles for starches gels.
487
Fig. 2. Scanning electron microscopy (SEM) images of quinoa starches (QS1, QS2,
488
QS3, QS4) at 25,000× magnification, maize starch (MS) and potato starch (PS) at
489
1,500× magnification.
490
Fig. 3. (a) X-ray diffractogram of starches; (b) FTIR spectra of starches.
Fig. 1
491
492
(a)
Water solubility index （ % ）
20
15
QS1
QS2 QS3 QS4
10
MS PS
5
0 55
493
65
75
(b)
85
95
Temperature(℃ )
Swelling power(g/g)
75
60
QS1 QS2 QS3 QS4 MS PS
45
30
15
0 55
65
75
494 495
85
95
Temperature(℃ )
(c)
1.8
QS1 QS2 QS3 QS4 MS PS
Viscosity(Pa·s)
1.5
1.2
0.9
0.6
0.3
0.0 0
496
(d)
50
100
Shear rate(1/s)
150
200
Storage Modulus(G')(Pa)
1000
QS1 QS2 QS3 QS4 MS PS
100
10 1
10
497
1000
(e)
Loss Modulus(G'‘)(Pa)
498
100
Angular frequency (rad/s)
100
QS1 QS2 QS3 QS4 MS PS 10
1
499
10
100
Angular frequency (rad/s)
1000
Fig. 2
500
QS1
QS2
QS3
QS4
MS
PS
501
502
503
Fig. 3
504
505
(a)
PS
MS
QS1 QS2 QS3
QS4
3600
3000
2400
1800
1200
600
-1
Wave number(cm )
506
PS MS QS1 QS2 QS3 QS4 5
10
15
20
25
30
Diffraction angle(2θ°)
507
(b)
35
40
45
508
Table 1
509
Proximate composition of starches. Sample
Total starch(%)
Protein (%)
Lipid (%)
Ash (%)
Amylose (%)
QS1
95.14±0.28a
1.23±0.02c
0.41±0.26bc
0.29±0.09a
10.90±0.15c
QS2
93.66±0.78b
1.67±0.04b
0.53±0.13bc
0.13±0.03cd
9.89±0.38de
QS3
95.30±0.35a
0.97±0.11d
0.26±0.15c
0.07±0.01d
9.43±0.17e
QS4
91.65±0.99cd
1.95±0.13a
0.91±0.20a
0.18±0.03c
10.16±0.13d
MS
92.76±0.48bc
0.33±0.10f
0.62±0.07b
0.17±0.06c
22.58±0.50a
PS
90.67±0.58d
0.87±0.05e
0.66±0.01b
0.25±0.01b
17.75±0.48b
510
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
511
the same column are significantly different (P < 0.05).
512
Table 2
513
Pasting and rheological properties of starches. Pasting parameters
Rheological parameters
Sample PT(℃)
PV(cP)
TV(cP)
BD(cP)
FV(cP)
SB(cP)
n
Lag ring area
QS1
72.60±0.11a
3551±5b
2975±4b
577±10e
3705±6a
730±8b
0.65b
72311c
QS2
72.63±0.10a
3285±8c
2651±8c
634± 9d
3272±5c
621±4c
0.79a
52586e
QS3
72.60±0.09a
2983±6d
2250±3d
733±11c
2692±4e
442±11e
0.92a
35979f
QS4
72.60±0.20a
3518±5b
3205±9a
313±8f
3684±7b
498±6d
0.86a
59430d
MS
75.93±0.15c
2669±3e
1794±4e
875±11b
2966±12d
1172±7a
0.64b
87728a
PS
67.90±0.20b
4144±4a
1492±6f
2653±4a
1660±4f
395±5f
0.18c
81043b
514
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
515
the same column are significantly different (P < 0.05). PT: pasting temperature; PV: peak
516
viscosity; TV:trough viscosity; FV: final viscosity; BD: breakdown (PV - TV); SB:setback (FV -
517
TV); n: flow characteristic index.
518
Table 3
519
Thermal properties of starches.
Sample
T0 (℃)
T p (℃)
Tc (℃)
△T(℃)
△H (J/g)
△H'(J/g)
R (%)
QS1
61.76±0.09b
67.44±0.02b
77.24±0.02b
15.48±0.12b
11.61±0.02c
-
-
QS2
57.89±0.13f
64.34±0.22d
74.43±0.37c
16.54±0.32a
11.76±0.05c
-
-
QS3
60.06±0.13d
65.15±0.09c
74.46±0.32c
14.40±0.33c
11.15±0.11d
-
-
QS4
58.31±0.20e
63.77±0.253
71.86±0.04d
13.55±0.18d
7.79±0.04e
-
-
MS
67.41±0.21a
71.00±0.06a
78.47±0.01a
11.07±0.21e
13.30±0.20b
4.26±0.04b
32.07±0.74a
PS
60.24±0.06c
63.98±0.10e
71.45±0.08e
11.21±0.14e
14.97±0.11a
4.30±0.03a
28.69±0.31b
520
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
521
the same column are significantly different (P < 0.05). To: onset temperature; Tp: peak
522
temperature; Tc: conclusion temperature; △T: gelatinization temperature range (Tc-T0) ΔH:
523
enthalpy change; △H': enthalpy change after retrogradation; R (%): retrogradation ratio (ΔH'/△
524
H). “-” indicates that no retrogradation has been detected.
525
Table 4
526
Particle size, crystallization, and molecular orders properties of starches. Particle size parameters
Crystallization
Molecular orders parameters
Sample Distribution (µm)
APS(µm)
Crystallinity(%)
DO
DD
QS1
0.71-5.56
1.58±0.01e
21.00±2.36c
0.698±0.005e
0.554±0.007b
QS2
0.46-4.15
1.21±0.01f
26.42±0.96bc
0.749±0.005d
0.560±0.021b
QS3
0.83-5.56
1.95±0.02c
29.67±1.23b
0.762±0.005c
0.551±0.002b
QS4
1.28-3.09
1.83±0.02d
26.64±1.02b
0.751±0.001d
0.515±0.001c
MS
3.16-30.22
14.20±0.02b
36.05±3.73c
0.883±0.003a
0.998±0.001a
PS
4.17-120.23
44.65±0.08a
25.68±2.28bc
0.826±0.004b
1.012±0.002a
527
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
528
the same column are significantly different (P < 0.05). APS: average particle size; DO:degree of
529
order (absorbance ratio of 1047cm-1and 1022cm-1 ); DD:degree of the double helix(absorbance
530
ratio of 995cm-1and 1022cm-1 ).
Highlights： Starch properties were measured in 4 quinoa starch varieties and 2 control starches.
Quinoa starch has high amylopectin content with good resistance to retrogradation.
Quinoa starch has lower degree of shear-thinning in QS4 and thixotropy in QS3.
Quinoa starch has irregular polygon granules with small diameters.
Conflict of Interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product of the manuscript entitled "Physicochemical and structural properties of starches isolated from quinoa varieties".
S0268-005X(19)31347-5
DOI:
https://doi.org/10.1016/j.foodhyd.2019.105515
Reference:
FOOHYD 105515
To appear in:
Food Hydrocolloids
Received Date: 19 June 2019 Revised Date:
12 November 2019
Accepted Date: 12 November 2019
Please cite this article as: Jiang, F., Du, C., Guo, Y., Fu, J., Jiang, W., Du, S.-k., Physicochemical and structural properties of starches isolated from quinoa varieties, Food Hydrocolloids (2019), doi: https:// doi.org/10.1016/j.foodhyd.2019.105515. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Ltd.
Physicochemical Quinoa (Chenopodium quinoa Willd.) seeds
properties
Isolation Pasting properties
Rheological properties
Relationship
Quinoa starch
Structural properties Morphology
Crystalline properties
1
Physicochemical and structural properties of starches
2
isolated from quinoa varieties
3
Fan Jianga, Chunwei Dua, Ying Guoa, Jiayang Fua, Wenqian Jianga, Shuang-kui Dua*
4
a
5
712100, China
6
* Corresponding author. E-mail: [email protected](Sh-K. Du)
7
Tel: 86-29-87092206; Fax: 86-29-87092486;
8
9
10
11
12
13
14
15
16
17
College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi
18
19
20
21
22
Abstract
23
Starches isolated from four quinoa varieties were analyzed for physicochemical,
24
morphological, and structural properties. All varieties of quinoa starches (QS) have
25
lower amylose content, ranging from 9.43% to 10.90%, than maize starch (22.58%)
26
and potato starch (17.75%) and thus has lower water solubility index and higher
27
swelling power. QS has lower pasting temperature and setback and breakdown than
28
maize starch. QS has lower enthalpy change (△H) and exhibits good resistance to
29
retrogradation. In terms of rheological properties, QS has lower degree of
30
shear-thinning and thixotropy than maize and potato starch. Additionally, QS has
31
irregular polygon granules with small granule diameters ranging from 1.21 µm to 1.95
32
µm and display the A-type X-ray diffraction pattern. The crystallinity of QS ranges
33
from 21.00% to 29.67%, which is significantly lower than that of maize starch.
34
Fourier-transform infrared spectroscopy showed that the QS structure is a double
35
helix and has a lower degree of order than the structures of maize and potato starch.
36
This study revealed the particular properties of QS with four varieties as compared
37
with other starch varieties.
38
Keywords: Quinoa starch; Structural properties; Pasting; Rheology; Thermal
39
properties
40
41
42
43
44
List of abbreviations
45
QS
quinoa starch
MS
maize starch
PS
potato starch
Q1
Haili quinoa seeds
Q2
Gannan quinoa seeds
Q3
Geermu quinoa seeds
Q4
Jingle quinoa seeds
QS1
Haili quinoa starch
QS2
Gannan quinoa starch
QS3
Geermu quinoa starch
QS4
Jingle quinoa starch
WSI
water solubility index
SP
swelling power
△H
enthalpy of gelatinization
G′
storage modulus
G′′
loss modulus
APS
average particle size
DO
degree of order
DD
degree of the double helix
46
1. Introduction
47
Quinoa (Chenopodium quinoa Willd.) is the main traditional food of the Inca
48
aborigines because of its high tolerance to extreme conditions, such as drought, frost,
49
salinity, and insect damage (Jacobsen, Mujica, & Jensen, 2003; Stikic et al., 2012).
50
Quinoa has huge genetic variability and persists in a wide range of environmental
51
conditions, providing possibility for testing in diverse regions of China, the USA,
52
Canada, India, England, Denmark, Greece, and Italy (Bhargava, Shukla, & Ohri, 2007;
53
Razzaghi et al., 2011). To date, quinoa production is increasing in some parts of China
54
where it grows well. Especially in Gansu, Qinghai and Shanxi regions, where there
55
are different altitudes and rainfall to cultivate different quinoa varieties. In recent
56
years, quinoa has attracted increasing interest worldwide because it has a high
57
nutritional value and does not contain gluten-type protein. It has been widely
58
recognized for its efficacy in preventing obesity, cardiovascular disease, diabetes, and
59
cancer (Escribano et al., 2017; Ferreira, Pallone, & Poppi, 2015; Navruz-Varli &
60
Sanlier, 2016).
61
Starch is the main nutrient component of many food substrates and plays an
62
important role in the functional and nutritional properties of processed foods
63
(Perez-Pacheco et al., 2014). Starch is the major component of quinoa grains,
64
accounting for 58% - 64% of the content of a quinoa grains. Amylose content in the
65
grains ranges from 4% to 25% (Qian & Kuhn, 1999; Watanabe, Peng, Tang, &
66
Mitsunaga, 2007). Previous studies showed that quinoa amylopectin had significant
67
amounts of short chains and super long chains (Li & Zhu, 2017a). Amylopectin chain
68
profile and amylose content affect the physicochemical and functional properties of
69
quinoa starch (QS). The starch granules of quinoa are irregular polygons ranging in
70
diameter from 1 µm to 3 µm, and have lower crystallinity than maize starch granules
71
(Ruales & Nair, 1994). QS exhibits higher water solubility index (WSI) and swelling
72
power (SP) than wheat and barley starch and highly susceptibility to enzyme (Tang,
73
Watanabe, & Mitsunaga, 2002). Moreover, QS has lower pasting temperature and
74
peak viscosity than normal maize starch and is far preferable to other starch varieties
75
as a thickening agent for fillings (Nienke Lindeboom, Chang, Falk, & Tyler, 2005;
76
Lorenz, 2010). In addition, QS is used in active food packaging to maintain food
77
safety and extend the shelf life of packaged food (Pagno et al., 2015).
78
Quinoa seeds from different regions also have a certain effect on its starch
79
quality. And the relationship between the physicochemical and structural properties of
80
QS is uncertain. In this work, the starches of four quinoa varieties from different
81
regions were determined the physicochemical and structural properties. The properties
82
of the starches were compared with those of maize starch and potato starch. The
83
systematic analysis of QS properties would provide basis for its development and
84
utilization.
85
2. Materials and methods
86
2.1 Materials
87
Four quinoa seeds were Haili quinoa (Q1) and Gannan quinoa (Q2) obtained
88
from the arid area and cold damp area with the altitude of 2000m - 4920m in Gansu,
89
Geermu quinoa (Q3) obtained the valley area with the altitude of 2300m in Qinghai,
90
Jingle quinoa (Q4) obtained from the barren soil area with the altitude of 1500m in
91
Shanxi. The seeds were then cultivated at the experimental open farm of Agricultural
92
Technology Promotion Center of Shenmu in Yulin. According to the wet milling
93
method reported by Ji, Seetharaman, and White (2004), QS was isolated from these
94
varieties and labeled QS1, QS2, QS3 and QS4. Normal maize starch (MS) and potato
95
starch (PS) were purchased from Aladdin Reagent Co., Ltd. (Shanghai, China). All the
96
chemicals used were of reagent grade.
97
2.2 Proximate composition
98
The crude protein content (PC%), lipid content (LC%), and ash content (AC%)
99
were determined in accordance with the method of AOAC (2005). A total starch assay
100
kit (Megazyme International Ireland Ltd., Ireland) was used to determine total starch
101
content (TS%). Amylose content (AC%) in the starch samples was determined by
102
using the iodine colorimetric determination, the method was described by Morrison
103
and Laignelet (1983) with some modification by Jan et al. (2017).
104
2.3 Physicochemical properties
105
2.3.1 Water solubility index (WSI) and swelling power (SP)
106
WSI (%) and SP (g/g) were determined according to the method of Tsai, Li, and
107
Lif (1997) with some modifications. Starch suspension of 1% was transferred to
108
centrifuge tubes and placed on a vortex mixer for 10 s. The samples were then heated
109
from 55 ℃ to 95 ℃ (at 10 ℃ intervals) for 30 min at thermostatic oscillating water
110
bath and then cooled to room temperature and centrifuged (3500 rpm, 15 min). The
111
supernatant was poured into a preweighed aluminum box to a constant weight (Ws) at
112
105 ℃. The remaining sediment paste was weighed (Wr) immediately. All
113
measurements were conducted in triplicates. The WSI (%) and SP (g/g) were
114
calculated. W WSI (%) = S ×100 W0
115
SP(g/g ) =
116
117
Wr W0 × (100 − WSI )
2.3.2 Pasting analysis
118
Pasting properties of starches were determined with a rapid visco-analyzer
119
(Perten, TechMastet, Sweden). The method described by Du et al. (2014) was used.
120
The main viscosity parameters were measured from the pasting curves using with
121
instrument software.
122
2.3.3 Thermal analysis
123
The thermal properties of starch were analyzed by using a differential scanning
124
calorimeter (Waters, Q2000, American) and through the method described by Ma et
125
al. (2017). The sealed crucibles were heated from 10 ℃ to 100 ℃ at a rate of 10 ℃/min.
126
The tested samples were placed at 4 ℃ for 7 days after the experiments. The
127
properties of retrogradation were determined by the same method.
128
2.3.4 Rheological analysis
129
The rheological properties of the starches were measured with TA Instruments
130
rheometer (TA Instruments, DHR-1, USA). The rheometer was employed with a 40
131
mm parallel plate geometry and a Peltier plate. After gelatinization, the 5% starch
132
suspension was placed between the parallel plate and Peltier plate with a gap of 1000
133
µm. The rheological parameters were obtained by using the producer of Steady State
134
Flow and OsciLLation.
135
2.4 Scanning electron microscopy
136
The morphological properties of the native starches were measured with a
137
scanning electron microscope (FEI, Nova Nano SEM-450, America).
138
2.5 Particle size analysis
139
The starch granules were suspended in water fully dispersed in an ultrasonic
140
oscillator. The particle size distribution was obtained by a laser diffraction particle
141
size analyzer (MALVERN, ZEN3600, England).
142
2.6 X-ray diffraction
143
X-ray analysis was performed with an X-ray diffractometer (Bruker, D8
144
ADVANCE A25, Germany) with a target Cu-anode X-ray tube. The scanning region
145
of the diffraction angle (2θ) was from 5° to 45° with a scanning step of 0.02° and
146
scanning speed of 6°/min. The crystallinity of each starch variety was calculated by
147
using Jade 6.5 software.
148
2.7 Fourier transformed infrared spectrometry (FTIR)
149
FTIR analysis was preformed with a Fourier transform infrared spectrometer
150
(Bruker, Vetex70, Germany) and through the method of Zeng et al. (2015) with minor
151
modifications. The samples were mingled with dried potassium bromide (1:100, v/v)
152
by an agate mortar. The mixed powder was placed into a vacuum compression and
153
pressured into a sheet. The spectra, recorded against a potassium bromide flake as the
154
background, were set from 400 cm-1 to 4000 cm-1, and the resolution was 4 cm-1.
155
Scanning was performed 16 times.
156
2.8 Statistical analysis
157
All measurements were in performed in triplicate. Data were analyzed with SPSS
158
software (IBM Corporation, NY, USA ). The significant differences were obtained by
159
analysis of variance (ANOVA) followed by Duncan’s multiple range test (P<0.05).
160
3. Results and discussion
161
3.1 Proximate composition
162
The proximate compositions of the four QS varieties, MS and PS samples are
163
listed in Table 1. The total starch content of QS ranged from 91.65% (QS4) to 95.30%
164
(QS3). The protein, lipid, and ash contents of the samples were relatively low,
165
indicating that the samples met the experimental requirements in the absence of
166
nonstarch lipids and hydrated fine fibers (Zhou, 2004; Jan, Panesar, Rana, & Singh,
167
2017). The amylose content of QS ranged from 9.43% in QS3 to 10.90% in QS1 and
168
was significantly lower than the amylose contents of MS (22.58%) and PS (17.75%).
169
This result is in the range of the values (0.3%-12.1%) reported by Lindeboom et al.
170
(2005). QS with low amylose content could contain large amounts of amylopectin and
171
thus cannot be easily retrograded.
172
3.2 Physicochemical properties
173
3.2.1 WSI and SP
174
The WSI and SP of the isolated QS, along with those of PS and MS, are
175
presented in Fig. 1(a) and (b). The WSI and SP values of the starches increased with
176
temperature. In the QS varieties, the maximum WSI and SP values were obtained in
177
QS2 (17.57 % and 28.15 g/g, respectively), and the minimum values in QS4 (6.45 %
178
and 21.83 g/g, respectively). The SP values of all the QS were significantly lower than
179
the SP of PS, thus, QS granules could well maintain their integrity under the
180
gelatinization temperature. However, the SP of QS was slightly higher than that of
181
MS, possibly because the QS particles were small and easy to interact with water
182
molecules. QS showed higher SP and lower WSI than MS. This condition could be
183
related to the low amylose content of QS because amylose restricts granule swelling
184
by reinforcing the internal network (Tang et al., 2002). The differences in WSI among
185
the starches may be due to the variations among their chain length distributions.
186
Additionally, QS amylopectin has significant amounts of short chains and super long
187
chains (Li & Zhu, 2018a).
188
3.2.2 Pasting properties
189
The pasting properties of starches are summarized in Table 2. Significant
190
differences (P<0.05) in pasting properties among starches were observed. No
191
differences in pasting temperature (PT) were observed among the four QS varieties.
192
The lowest peak viscosity (PV) and setback (SB) and the highest breakdown (BD) of
193
QS3 may be due to its the lowest amylose content (Table1). The PT of QS ranged
194
from 72.60℃ to 72.63℃ and was higher than that of PS (67.90℃) and lower than that
195
of MS (75.93℃). These higher PT values indicated that starches are difficult to swell
196
and rupture (Du et al., 2014). The PV of QS (2983-3551 cP) was higher than MS
197
(2669 cP) and lower than PS (4144 cP). This trend was consistent with SP discussed
198
above (Fig.1(a)). High PV values are associated with the high degree of granule
199
swelling or water binding capacity of starches (Osundahunsi, Fagbemi, Kesselman, &
200
Shimoni, 2003). The low BD of QS indicated that this paste had the stronger shear
201
resistance. The SB of QS ranged from 442 cP (QS3) to 730 cP (QS1) and was much
202
lower than that of MS (1172 cP). This is related to the low amylose content of QS
203
(Table 1). The values of QS pasting parameters were almost accordant to the values
204
obtained in the previous study (Steffolani, León, & Pérez, 2013). The relatively low
205
BD and SD and high PV of QS suggested that this starch has low hardness,
206
gumminess, chewiness, and high adhesiveness to provide particular texture and
207
application (Wu, Morris, & Murphy, 2014).
208
3.2.3 Thermal properties
209
The starch gelatinization transition temperatures (onset, To; peak, Tp; and
210
conclusion, Tc), gelatinization temperature range (△T) along with enthalpy of
211
gelatinization (△H, △H'), and retrogradation ratio (R) are summarized in Table 2. QS
212
had lower To, Tp, and Tc than MS but the values are close to those of PS, since QS had
213
low crystallinity and its granules were easy to gelatinize. The differences in
214
gelatinization temperature may be influenced by the branch-chain length of
215
amylopectin, the amylose content, and the presence of endogenous components, such
216
as lipids and proteins (Hoover, Hughes, Chung, & Liu, 2010; Nadjemi & Deroanne,
217
2009). QS had a wide △T especially in QS2 as compared with MS and PS, and QS4
218
had the lowest △H. This result may reflect that QS has a wide range of crystal
219
stability and longer branch chains in its amylopectin content than the control
220
(Fredriksson, Silverio, Andersson, Eliasson, & Aman, 1998). The To, Tp, Tc, and △H
221
of QS were higher than the values reported by Fuentes et al. (2019)，and by Jan et al.
222
(2017). This result might be due to the different genotypes of quinoa seeds from
223
different geographical locations. QS were not present in retrogradation after 7 days at
224
4 ℃ compared with MS (32.07%) and PS (28.69%), suggesting that QS had a great
225
amount of amylopectin with long branch chains to resist retrogradation. The long
226
branch chains of amylopectin have the high degree of polymerization. The orientation
227
arrangement of long branch chains is harder than short chain, which reduce the
228
recrystallization rate of starch so that starch can resist to retrogradation (Hoover,
229
Hughes, Chung, & Liu, 2010). The amylopectin structure of QS has an important role
230
in its thermal properties.
231
3.2.4 Rheological properties
232
The Herschel-Bulkley (τ=τ0 + Kγn) mathematical model was used to fit the
233
starch paste based on the relationship between shear stress and shear rate. This model
234
described well the different starch gel systems even at low shear rates (Li & Zhu,
235
2017). The flow characteristic index (n) of this model ranged from 0.65 to 0.92 (Table
236
2), reflecting the pseudoplastic characteristics (n<1) of the QS paste. This QS paste
237
property is in accordance with the Not-Newton fluidity law and has a different degree
238
of thixotropy. The flow curves of starch pastes from different cultivars exhibited lag
239
rings, which areas are positively correlated with thixotropy (Kong, Kasapis, Bertoft,
240
& Corke, 2010). The mean lag ring areas of the starches had the following order:
241
QS1 > QS4 > QS2 > QS3 (Table 2). The experimental results were possibly affected
242
by the content of amylose and internal chain structure of amylopectin (Wang et al.,
243
2010). The phenomenon of increasing shear force and decreasing apparent viscosity
244
revealed that QS paste could be considered as a shear-thinning system (Fig.1(c)). The
245
shear-thinning phenomenon in QS3 was the most obvious but lower in extent than
246
that in MS and PS possibly because of the low amylose content of QS. These results
247
are in accordance with previous reports (Ahmed, Thomas, Arfat, & Joseph, 2018).
248
In general, frequency scanning has been used widely to provide further insights
249
into the dynamic rheological behavior of materials (Kong et al., 2010). The storage
250
modulus (G′) and loss modulus (G′′) of all kinds of starch pastes increased steadily
251
during frequency scanning range. G′ was obviously higher than G″ within the
252
frequency scanning range, and no crossing was observed between them, except in the
253
PS paste (Fig. 1(d) and (e)). The result showed that the gel strength of QS and MS
254
were stronger than PS throughout the frequency range mostly due to the reordering of
255
leached amylose. The amylose fixed by hydrogen bonds during cooling can restrict
256
the molecules or particles from moving (Li & Zhu, 2018b). The high G′ represents a
257
solid and elastic gel network structure and with high degrees of cross-linking (Ai &
258
Jane, 2015). Previous research showed that the internal structure of QS with super
259
long chain fractions of amylopectin may play an important role in the rheological
260
properties (Li & Zhu, 2018b).
261
3.3 Morphological properties
262
The scanning electron microscopy micrographs of the starch granules are shown
263
in Fig. 2. The four QS varieties showed similar granular polygons and irregularity,
264
which were the same with those of MS granules but different from those of PS
265
granules. Compared with MS and PS, the surface of QS granules appeared to be rough
266
but with no fissure (Fig. 2). The granule morphology agreed with the previous reports
267
in starches from different quinoa varieties (Lindeboom, Chang, Tyler, & Chibbar,
268
2005; Tang et al., 2002).
269
Size distributions of the starch granules are presented in Table 4. The average
270
particle size of the QS ranged from 1.21 µm (QS2) to 1.95 µm (QS3). These values
271
were significantly smaller than those of MS (14.20 µm) and PS (44.65 µm). QS
272
presented a wide size distribution because they formed aggregated structures, which
273
are typical of most starches consisting of small granules (Qian & Kuhn, 1999).
274
Similar results were observed by Steffolani et al. (2013). Starch granule and particle
275
size distribution may affect physicochemical properties, such as solubility, pasting,
276
and enzyme susceptibility. Starch granules from different botanical origins differ in
277
size and shape with various genotype and growing conditions (Hoover & Sosulski,
278
1991).
279
3.4 X-ray diffraction
280
X-ray diffractometry was used to evaluate the characteristics of the crystalline
281
structure of starch granules. The diffraction peaks of QS and MS appeared near 15°,
282
17° and 23°. All the QS varieties showed the A-type crystalline arrangement patterns,
283
which are common to cereal starches. Meanwhile, PS showed the B-type crystalline
284
pattern with diffraction peaks near 17°, 19°, 22° and 24° (Fig. 3(a)). This result is
285
consistent with previous reported results (Ahmed et al., 2018). The degree of
286
crystallinity of QS ranging from 21.00% in QS1 to 29.67% in QS3 was lower than
287
that in MS in 36.05%. However, the values were close to PS with 25.68% (Table 4).
288
The crystallinity for QS presented here was lower than the results reported by
289
Steffolani et al. (2013). The chemical structure, especially the chain length
290
distribution of amylopectin and composition of starches, may affect such differences
291
among starches (Zobel, 2010). As previously reported, QS had a significantly large
292
number of A-chains with fingerprint structure, which led to a low degree of
293
crystallinity (Li & Zhu, 2018a). The crystalline regions are related to the structure and
294
content of amylopectin molecules, whereas the amorphous regions are related to
295
amylose molecules (Zobel, 1998). The crystallinity of four QS was negatively
296
correlated with the amylose content, showing that QS1 had low crystallinity with high
297
amylose content.
298
3.5 Fourier transform infrared spectrometer
299
FTIR analysis technique was used to reflect the short-range ordered structure of
300
starch as the order of double helix structure of starch. The FTIR spectra of the starch
301
samples are illustrated in Fig. 3(b). No difference was observed in the detected peaks
302
of four QS varieties, indicating no difference in the chemical groups among the QS
303
varieties. The spectrum was characterized by three typical absorption peaks with
304
maximum absorbance at 995, 1022, and 1047 cm-1. These values can well reflect the
305
crystalline properties of starch granules (López-Barón et al., 2018). The intensity ratio
306
at 1047/1022 cm-1 could reflect the degree of order (DO), and the intensity ratio at
307
995/1022 cm-1 characterized the degree of the double helix (DD) (Zeng et al., 2015).
308
The DO values of QS ranging from 0.698 in QS1 to 0.762 in QS3 were lower than
309
that in MS of 0.883 and PS of 0.826 (Table 4). A positive correlation was observed
310
between the DO and starch crystallinity, indicating that the crystalline structure was
311
formed by orderly starch chains. The DD values of QS ranged from 0.515 to 0.560,
312
which were generally lower than those of MS (0.998) and PS (1.012). The results
313
were similar to the results reported previously by Jasim Ahmed (Ahmed et al., 2018),
314
suggesting that QS has a lower number of double helix structure than MS and PS. The
315
lower number of double helix structure resulted in lower △H of QS (Table 3). The
316
differences in results among the starches could be attributed to the biological origin,
317
the contents of amylose and amylopectin, and the amylopectin molecular structure (Li
318
& Zhu, 2017b).
319
4. Conclusion
320
Isolated starches from four quinoa samples, maize, and potato showed
321
variation in physicochemical and morphological structure. QS had lower amylose
322
content and thus had lower WSI and higher SP. QS exhibited lower PT and SB and
323
BD than MS, indicating it had the stronger shear resistance. QS with long branch
324
chains had the widest range of △T and lowest △H among the starches, revealing that
325
QS has good resistance to retrogradation. Moreover, QS had the lowest degree of
326
shear thinning and thixotropy, and QS1 had the highest G′ and G′′. These results may
327
indicate that QS are suitable for industrial production. QS morphology was irregular
328
polygon, had small granule diameter (1.21 µm-1.95 µm), showed the A-type X-ray
329
diffraction pattern, and had a crystallinity of 21.00%-29.67%, which was significantly
330
lower than that of MS. The lowest degree of order and double helix of QS structure
331
were compared with those of MS and PS. The influence of amylopectin on QS
332
properties remains to be explored. These properties may provide basis for the
333
utilization of QS in various applications.
334
Acknowledgements
335
The authors would like to thank Shaanxi Province Key Research and
336
Development Program Project (2017NY-177) and Shaanxi Province Agricultural
337
Science and Technology Innovation and Transformation Project (NYKJ-2018-YL19)
338
for the support.
339
References
340
AOAC. (2005). Official methods of analysis of AOAC International 18th edn. AOAC
341
International, Gaithersberg. https://doi.org/10.1016/0924-2244(95)90022-5.
342
Ahmed, J., Thomas, L., Arfat, Y. A., & Joseph, A. (2018). Rheological, structural and
343
functional properties of high-pressure treated quinoa starch in dispersions.
344
Carbohydrate Polymers, 197, 649-657.
345
https://doi.org/10.1016/j.carbpol.2018.05.081.
346 347
Ai, Y., & Jane, J.-l. (2015). Gelatinization and rheological properties of starch. Starch - Stärke, 67(3-4), 213-224. https://doi.org/10.1002/star.201400201.
348
Bhargava, A., Shukla, S., & Ohri, D. (2007). Genetic variability and interrelationship
349
among various morphological and quality traits in quinoa (Chenopodium
350
quinoa
351
https://doi.org/10.1016/j.fcr.2006.10.001.
Willd.).
Field
Crops
Research,
101(1),
104-116.
352
Du, S. K., Jiang, H., Ai, Y., & Jane, J. L. (2014). Physicochemical properties and
353
digestibility of common bean (Phaseolus vulgaris L.) starches. Carbohydrate
354
Polymers, 108, 200-205. https://doi.org/10.1016/j.carbpol.2014.03.004.
355
Escribano,
J.,
Cabanes,
J.,
Jimenez-Atienzar,
M.,
Ibanez-Tremolada,
M.,
356
Gomez-Pando, L. R., Garcia-Carmona, F., & Gandia-Herrero, F. (2017).
357
Characterization of betalains, saponins and antioxidant power in differently
358
colored quinoa (Chenopodium quinoa) varieties. Food Chemistry, 234,
359
285-294. https://doi.org/10.1016/j.foodchem.2017.04.187.
360
Ferreira, D. S., Pallone, J. A. L., & Poppi, R. J. (2015). Direct analysis of the main
361
chemical constituents in Chenopodium quinoa grain using Fourier transform
362
near-infrared spectroscopy. Food Control, 48, 91-95.
363
https://doi.org/10.1016/j.foodcont.2014.04.016.
364
Fredriksson, H., Silverio, J., Andersson, R., Eliasson, A. C., & Åman, P. (1998). The
365
influence of amylose and amylopectin characteristics on gelatinization and
366
retrogradation properties of different starches. Carbohydrate Polymers,
367
35(3–4), 119-134. https://doi.org/10.1016/S0144-8617(97)00247-6.
368
Hoover, R., Hughes, T., Chung, H. J., & Liu, Q. (2010). Composition, molecular
369
structure, properties, and modification of pulse starches: A review. Food
370
Research International, 43(2), 399-413.
371
https://doi.org/10.1016/j.foodres.2009.09.001.
372
Jacobsen, S. E., Mujica, A., & Jensen, C. R. (2003). The Resistance of Quinoa
373
(Chenopodium quinoa Willd.) to Adverse Abiotic Factors. Food Reviews
374
International, 19(1-2), 99-109. https://doi.org/10.1081/FRI-120018872.
375
Jan, K. N., Panesar, P. S., Rana, J. C., & Singh, S. (2017). Structural, thermal and
376
rheological properties of starches isolated from Indian quinoa varieties.
377
International
378
https://doi.org/10.1016/j.ijbiomac.2017.04.027.
Journal
of
Biological
Macromolecules,
102,
315-322.
379
Ji, Y., Seetharaman, K., & White, P. J. (2004). Optimizing a Small-Scale Corn-Starch
380
Extraction Method for Use in the Laboratory. Cereal Chemistry Journal, 81(1),
381
55-58. https://doi.org/10.1094/CCHEM.2004.81.1.55.
382
Kong, X., Kasapis, S., Bertoft, E., & Corke, H. (2010). Rheological properties of
383
starches from grain amaranth and their relationship to starch structure. Starch -
384
Stärke, 62(6), 302-308. https://doi.org/10.1002/star.200900235.
385 386
Li, D., & Zhu, F. (2017). Physicochemical properties of kiwifruit starch. Food Chemistry, 220, 129-136. https://doi.org/10.1016/j.foodchem.2016.09.192.
387
Li, G., & Zhu, F. (2017a). Amylopectin molecular structure in relation to
388
physicochemical properties of quinoa starch. Carbohydrate Polymers, 164,
389
396-402. https://doi.org/10.1016/j.carbpol.2017.02.014.
390
Li, G., & Zhu, F. (2017b). Molecular structure of quinoa starch. Carbohydrate
391
Polymers, 158, 124-132. https://doi.org/10.1016/j.carbpol.2016.12.001.
392
Li, G., & Zhu, F. (2018a). Quinoa starch: Structure, properties, and applications.
393
Carbohydrate Polymers, 181, 851-861.
394
https://doi.org/10.1016/j.carbpol.2017.11.067.
395
Li, G., & Zhu, F. (2018b). Rheological properties in relation to molecular structure of
396
quinoa starch. International Journal of Biological Macromolecules, 114,
397
767-775. https://doi.org/10.1016/j.ijbiomac.2018.03.039.
398
Lindeboom, N., Chang, P. R., Falk, K. C., & Tyler, R. T. (2005). Characteristics of
399
Starch from Eight Quinoa Lines. Cereal Chemistry, 82(2), 216-222.
400
https://doi.org/10.1094/CC-82-0216.
401
Lindeboom, N., Chang, P. R., Tyler, R. T., & Chibbar, R. N. (2005). Granule-Bound
402
Starch Synthase I (GBSSI) in Quinoa ( Chenopodium quinoa Willd.) and Its
403
Relationship to Amylose Content. Cereal Chemistry, 82(3), 246-250.
404
https://doi.org/10.1094/CC-82-0246.
405
López-Barón, N., Sagnelli, D., Blennow, A., Holse, M., Gao, J., Saaby, L., Vasanthan,
406
T. (2018). Hydrolysed pea proteins mitigate in vitro wheat starch digestibility.
407
Food Hydrocolloids, 79, 117-126.
408
https://doi.org/10.1016/j.foodhyd.2017.12.009.
409
Lorenz, K. (2010). Quinoa (Chenopodium quinoa) starch physico-chemical properties
410
and functional characteristics. Starch - Stärke, 42(3), 81-86.
411
https://doi.org/10.1002/star.19900420302.
412
Ma, M., Wang, Y., Wang, M., Jane, J.-l., & Du, S.-k. (2017). Physicochemical
413
properties and in vitro digestibility of legume starches. Food Hydrocolloids,
414
63, 249-255. https://doi.org/10.1016/j.foodhyd.2016.09.004.
415
Morrison, W. R., & Laignelet, B. (1983). An improved colorimetric procedure for
416
determining apparent and total amylose in cereal and other starches. Journal of
417
Cereal Science, 1(1), 9-20. https://doi.org/10.1016/S0733-5210(83)80004-6.
418
Nadjemi, B., & Deroanne, C. (2009). Physicochemical and functional properties of
419
starches from sorghum cultivated in the Sahara of Algeria. Carbohydrate
420
Polymers, 78(3), 475-480. https://doi.org/10.1016/j.carbpol.2009.05.010.
421
Navruz-Varli, S., & Sanlier, N. (2016). Nutritional and health benefits of quinoa
422
( Chenopodium quinoa Willd.). Journal of Cereal Science, 69, 371-376.
423
424
https://doi.org/10.1016/j.jcs.2016.05.004.
Osundahunsi, O. F., Fagbemi, T. N., Kesselman, E., & Shimoni, E. (2003).
425
Comparison of the physicochemical properties and pasting characteristics of
426
flour and starch from red and white sweet potato cultivars. Journal of
427
Agriculture and Food Chemistry, 51(8), 2232-2236.
428
https://doi.org/10.1021/jf0260139.
429
Pagno, C. H., Costa, T. M., de Menezes, E. W., Benvenutti, E. V., Hertz, P. F., Matte,
430
C. R., Flores, S. H. (2015). Development of active biofilms of quinoa
431
(Chenopodium quinoa W.) starch containing gold nanoparticles and evaluation
432
of antimicrobial activity. Food Chemistry, 173, 755-762.
433
https://doi.org/10.1016/j.foodchem.2014.10.068.
434
Perez-Pacheco, E., Moo-Huchin, V. M., Estrada-Leon, R. J., Ortiz-Fernandez, A.,
435
May-Hernandez, L. H., Rios-Soberanis, C. R., & Betancur-Ancona, D. (2014).
436
Isolation and characterization of starch obtained from Brosimum alicastrum
437
Swarts seeds. Carbohydrate Polymers, 101, 920-927.
438
https://doi.org/10.1016/j.carbpol.2013.10.012.
439
Qian, J., & Kuhn, M. (1999). Characterization of Amaranthus cruentus and
440
Chenopodium quinoa Starch. Starch - Stärke, 51(4), 116–120.
441
https://doi.org/10.1002/(SICI)1521-379X(199904)51:43.0.CO;2-R.
442 443
Razzaghi, F., Ahmadi, S. H., Adolf, V. I., Jensen, C. R., Jacobsen, S. E., & Andersen, M. N. (2011). Water Relations and Transpiration of Quinoa (Chenopodium
444
quinoa Willd.) Under Salinity and Soil Drying. Journal of Agronomy and
445
Crop Science, 197(5), 348-360.
446
https://doi.org/10.1111/j.1439-037X.2011.00473.x.
447
Ruales, J., & Nair, B. M. (1994). Properties of starch and dietary fibre in raw and
448
processed quinoa (Chenopodium quinoa, Willd) seeds. Plant Foods for
449
Human Nutrition, 45(3), 223-246. https://doi.org/10.1007/bf01094092.
450
Steffolani, M. E., León, A. E., & Pérez, G. T. (2013). Study of the physicochemical
451
and functional characterization of quinoa and kañiwa starches. Starch - Stärke,
452
65(11-12), 976-983. https://doi.org/10.1002/star.201200286.
453
Stikic, R., Glamoclija, D., Demin, M., Vucelic-Radovic, B., Jovanovic, Z.,
454
Milojkovic-Opsenica, D., Milovanovic, M. (2012). Agronomical and
455
nutritional evaluation of quinoa seeds (Chenopodium quinoa Willd.) as an
456
ingredient in bread formulations. Journal of Cereal Science, 55(2), 132-138.
457
https://doi.org/10.1016/j.jcs.2011.10.010.
458
Tang, H., Watanabe, K., & Mitsunaga, T. (2002). Characterization of storage starches
459
from quinoa, barley and adzuki seeds. Carbohydrate Polymers, 49(1), 13-22.
460
https://doi.org/10.1016/s0144-8617(01)00292-2.
461
Tsai, M. L., Li, C. F., & Lif, C. Y. (1997). Effects of granular structures on the pasting
462
behaviors of starches. Cereal Chemistry, 74(6), 750-757.
463
https://doi.org/10.1094/CCHEM.1997.74.6.750.
464
Wang, J., Yu, L., Xie, F. W., Chen, L., Li, X. X., & Liu, H. S. (2010). Rheological
465
properties
and
phase
transition
of
cornstarches
with
different
466
amylose/amylopectin ratios under shear stress. Starch - Stärke, 62(12),
467
667-675. https://doi.org/10.1002/star.201000059.
468
Watanabe, K., Peng, N. L., Tang, H., & Mitsunaga, T. (2007). Molecular Structural
469
Characteristics of Quinoa Starch. Food Science & Technology International
470
Tokyo, 13(1), 73-76. https://doi.org/10.3136/fstr.13.73.
471
Wu, G., Morris, C. F., & Murphy, K. M. (2014). Evaluation of texture differences
472
among varieties of cooked quinoa. Journal of Food Science, 79(11),
473
S2337-2345. https://doi.org/10.1111/1750-3841.12672.
474
Zeng, S., Wu, X., Lin, S., Zeng, H., Lu, X., Zhang, Y., & Zheng, B. (2015). Structural
475
characteristics and physicochemical properties of lotus seed resistant starch
476
prepared
477
https://doi.org/10.1016/j.foodchem.2015.03.143.
by
different
methods.
Food
Chemistry,
186,
213-222.
478
Zhou, Y. (2004). Relationship between α-amylase degradation and the structure and
479
physicochemical properties of legume starches. Carbohydrate Polymers, 57(3),
480
299-317. https://doi.org/10.1016/j.carbpol.2004.05.010.
481 482
Zobel, H. F. (2010). Molecules to Granules: A Comprehensive Starch Review. Starch - Stärke, 40(2), 44-50. https://doi.org/10.1002/star.19880400203.
483
Figure captions:
484
Fig. 1. (a) Water solubility index and (b) swelling power of starches; (c) Apparent
485
viscosity plot against shear rate; (d) Storage modulus and loss modulus (e) of
486
frequency sweep profiles for starches gels.
487
Fig. 2. Scanning electron microscopy (SEM) images of quinoa starches (QS1, QS2,
488
QS3, QS4) at 25,000× magnification, maize starch (MS) and potato starch (PS) at
489
1,500× magnification.
490
Fig. 3. (a) X-ray diffractogram of starches; (b) FTIR spectra of starches.
Fig. 1
491
492
(a)
Water solubility index （ % ）
20
15
QS1
QS2 QS3 QS4
10
MS PS
5
0 55
493
65
75
(b)
85
95
Temperature(℃ )
Swelling power(g/g)
75
60
QS1 QS2 QS3 QS4 MS PS
45
30
15
0 55
65
75
494 495
85
95
Temperature(℃ )
(c)
1.8
QS1 QS2 QS3 QS4 MS PS
Viscosity(Pa·s)
1.5
1.2
0.9
0.6
0.3
0.0 0
496
(d)
50
100
Shear rate(1/s)
150
200
Storage Modulus(G')(Pa)
1000
QS1 QS2 QS3 QS4 MS PS
100
10 1
10
497
1000
(e)
Loss Modulus(G'‘)(Pa)
498
100
Angular frequency (rad/s)
100
QS1 QS2 QS3 QS4 MS PS 10
1
499
10
100
Angular frequency (rad/s)
1000
Fig. 2
500
QS1
QS2
QS3
QS4
MS
PS
501
502
503
Fig. 3
504
505
(a)
PS
MS
QS1 QS2 QS3
QS4
3600
3000
2400
1800
1200
600
-1
Wave number(cm )
506
PS MS QS1 QS2 QS3 QS4 5
10
15
20
25
30
Diffraction angle(2θ°)
507
(b)
35
40
45
508
Table 1
509
Proximate composition of starches. Sample
Total starch(%)
Protein (%)
Lipid (%)
Ash (%)
Amylose (%)
QS1
95.14±0.28a
1.23±0.02c
0.41±0.26bc
0.29±0.09a
10.90±0.15c
QS2
93.66±0.78b
1.67±0.04b
0.53±0.13bc
0.13±0.03cd
9.89±0.38de
QS3
95.30±0.35a
0.97±0.11d
0.26±0.15c
0.07±0.01d
9.43±0.17e
QS4
91.65±0.99cd
1.95±0.13a
0.91±0.20a
0.18±0.03c
10.16±0.13d
MS
92.76±0.48bc
0.33±0.10f
0.62±0.07b
0.17±0.06c
22.58±0.50a
PS
90.67±0.58d
0.87±0.05e
0.66±0.01b
0.25±0.01b
17.75±0.48b
510
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
511
the same column are significantly different (P < 0.05).
512
Table 2
513
Pasting and rheological properties of starches. Pasting parameters
Rheological parameters
Sample PT(℃)
PV(cP)
TV(cP)
BD(cP)
FV(cP)
SB(cP)
n
Lag ring area
QS1
72.60±0.11a
3551±5b
2975±4b
577±10e
3705±6a
730±8b
0.65b
72311c
QS2
72.63±0.10a
3285±8c
2651±8c
634± 9d
3272±5c
621±4c
0.79a
52586e
QS3
72.60±0.09a
2983±6d
2250±3d
733±11c
2692±4e
442±11e
0.92a
35979f
QS4
72.60±0.20a
3518±5b
3205±9a
313±8f
3684±7b
498±6d
0.86a
59430d
MS
75.93±0.15c
2669±3e
1794±4e
875±11b
2966±12d
1172±7a
0.64b
87728a
PS
67.90±0.20b
4144±4a
1492±6f
2653±4a
1660±4f
395±5f
0.18c
81043b
514
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
515
the same column are significantly different (P < 0.05). PT: pasting temperature; PV: peak
516
viscosity; TV:trough viscosity; FV: final viscosity; BD: breakdown (PV - TV); SB:setback (FV -
517
TV); n: flow characteristic index.
518
Table 3
519
Thermal properties of starches.
Sample
T0 (℃)
T p (℃)
Tc (℃)
△T(℃)
△H (J/g)
△H'(J/g)
R (%)
QS1
61.76±0.09b
67.44±0.02b
77.24±0.02b
15.48±0.12b
11.61±0.02c
-
-
QS2
57.89±0.13f
64.34±0.22d
74.43±0.37c
16.54±0.32a
11.76±0.05c
-
-
QS3
60.06±0.13d
65.15±0.09c
74.46±0.32c
14.40±0.33c
11.15±0.11d
-
-
QS4
58.31±0.20e
63.77±0.253
71.86±0.04d
13.55±0.18d
7.79±0.04e
-
-
MS
67.41±0.21a
71.00±0.06a
78.47±0.01a
11.07±0.21e
13.30±0.20b
4.26±0.04b
32.07±0.74a
PS
60.24±0.06c
63.98±0.10e
71.45±0.08e
11.21±0.14e
14.97±0.11a
4.30±0.03a
28.69±0.31b
520
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
521
the same column are significantly different (P < 0.05). To: onset temperature; Tp: peak
522
temperature; Tc: conclusion temperature; △T: gelatinization temperature range (Tc-T0) ΔH:
523
enthalpy change; △H': enthalpy change after retrogradation; R (%): retrogradation ratio (ΔH'/△
524
H). “-” indicates that no retrogradation has been detected.
525
Table 4
526
Particle size, crystallization, and molecular orders properties of starches. Particle size parameters
Crystallization
Molecular orders parameters
Sample Distribution (µm)
APS(µm)
Crystallinity(%)
DO
DD
QS1
0.71-5.56
1.58±0.01e
21.00±2.36c
0.698±0.005e
0.554±0.007b
QS2
0.46-4.15
1.21±0.01f
26.42±0.96bc
0.749±0.005d
0.560±0.021b
QS3
0.83-5.56
1.95±0.02c
29.67±1.23b
0.762±0.005c
0.551±0.002b
QS4
1.28-3.09
1.83±0.02d
26.64±1.02b
0.751±0.001d
0.515±0.001c
MS
3.16-30.22
14.20±0.02b
36.05±3.73c
0.883±0.003a
0.998±0.001a
PS
4.17-120.23
44.65±0.08a
25.68±2.28bc
0.826±0.004b
1.012±0.002a
527
Results are means ± standard deviations of duplicate analysis. Values with the different letters in
528
the same column are significantly different (P < 0.05). APS: average particle size; DO:degree of
529
order (absorbance ratio of 1047cm-1and 1022cm-1 ); DD:degree of the double helix(absorbance
530
ratio of 995cm-1and 1022cm-1 ).
Highlights： Starch properties were measured in 4 quinoa starch varieties and 2 control starches.
Quinoa starch has high amylopectin content with good resistance to retrogradation.
Quinoa starch has lower degree of shear-thinning in QS4 and thixotropy in QS3.
Quinoa starch has irregular polygon granules with small diameters.
Conflict of Interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product of the manuscript entitled "Physicochemical and structural properties of starches isolated from quinoa varieties".