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The effect of different nixtamalisation processes on some physicochemical properties, nutritional composition and glycemic index
Journal of Cereal Science 65 (2015) 140e146
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The effect of different nixtamalisation processes on some physicochemical properties, nutritional composition and glycemic index Rosa María Mariscal Moreno a, J.D.C. Figueroa a, *, David Santiago-Ramos b, nez Sandoval a, Patricia Rayas-Duarte c, nimo Ara mbula Villa a, Sergio Jime Gero a ctor Eduardo Martínez Flores d Juan Ve les-Medina , He Jose CINVESTAV-Unidad Quer etaro, Libramiento Norponiente No. 2000, Fracc Real de Juriquilla, Quer etaro, Qro 76230, Mexico noma de Quer PROPAC, Universidad Auto etaro. Cerro de las Campanas S/N, Col. Las Campanas, Quer etaro, Quer etaro C. P. 76010, Mexico c Robert M. Kerr Food & Agricultural Products Center, Biochemistry and Molecular Biology, Oklahoma State University, 123 FAPC, Stillwater, OK 74078-6055, USA d s de Hidalgo, Tzintzuntzan 173, Col. Matamoros, Morelia Mich., Mexico Facultad de Químico Farmacobiología, Universidad Michoacana de San Nicola a
b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 24 March 2015 Received in revised form 24 June 2015 Accepted 28 June 2015 Available online 2 July 2015
The objective was to evaluate corn tortillas made from three nixtamalisation processes including Traditional with lime (TNP), Classic with ashes (CNP) and Ecological with Ca salts (ENP), and their effect on mineral content (Ca, Fe, K, and Mg), chemical composition, resistant starch (RS), and glycemic index (GI). ENP with calcium propionate and carbonate had higher fat values than tortillas from CNP. EPN and CNP presented the higher dietary fibre, explained by the highest pericarp retention. In TNP the pericarp and external layers were lost during the cooking, steeping and washing steps and had lower crude fiber. The amount of RS increased in nixtamal and tortillas independently of nixtmalisation processes. Annealing of starch was shown by the increase of onset, peak and final gelatinisation temperatures in nixtamalised products compared with untreated maize. Gelatinisation was higher for calcium propionate ENP and 1% ash CNP. Native maize changed from A-type to V-type pattern in nixtamalised products denoting the formation of amylose-lipid complexes. Overall, nixtamalisation processes and salts used increased RS. The GI was affected by chemical composition in tortillas and amount of RS. Tortillas made from ENP Ca propionate and ENP 1% ash CNP can be classified as low GI foods. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Nixtamalisation Resistant starch Chemical composition Glycemic index
1. Introduction Maize for human consumption is processed in Mexico following the pre-Columbian technique known as nixtamalisation which is a process whereby maize is boiled in water containing Ca(OH)2 (lime), the nixtamal (cooked maize), obtained is steeped overnight, washed and ground to obtain masa. The masa can be used immediately for tortillas, or dried and grounded to produce dry masa flour (nixtamalised flour). The nixtamalisation process is critical in enhancing the nutritional value of maize and is used to make several products (tortillas, tamales, pozole, atoles, totopos, snacks,
* Corresponding author. E-mail address: jfi[email protected] (J.D.C. Figueroa). http://dx.doi.org/10.1016/j.jcs.2015.06.016 0733-5210/© 2015 Elsevier Ltd. All rights reserved.
tacos, tostadas, and nachos) which are staple foods in Mexico, Central America and widely consumed in United States (Campechano et al., 2012; Figueroa et al., 2013). Archeological evidence suggests that the ancient nixtamalisation process (Classic Nixtamalisation Process, CNP) used by the Mayas in the Preclassic period (1200-250 B C.) consisted in cooking maize with wood ashes (Katz et al., 1974). Later the Aztecs, settled in central Mexico around 1325 A.D. substituted ashes for lime, though it is not clear exactly when, creating the Traditional Nixtamalisation Process (TNP) that is remained used in present commercial operations. There is a need to improve the sustainability of the TNP which uses large volume of water producing high dry matter losses (3e15%) in the nixtamal during the cooking and washing steps (Campechano et al., 2012). During the mentioned processing
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steps nutrients are lost, including vitamins, fat, protein, dietary s et al., fibre and some biological active compounds (Maya-Corte 2010; Campechano et al., 2012; Rodríguez et al., 2013). In addition, the nejayote (cooking solution) is an environmental pollutant due to its high alkalinity which also damages the processing equipment. Recently, an Ecological Nixtamalisation Process (ENP) patented by Figueroa et al. (2011) addresses some of challenges of environmental and nutritional effects. The ENP replaces calcium hydroxide with commercially available calcium salts (e. g. calcium propionate and calcium carbonate). The masa and tortillas made from ENP had improved appearance and sensory properties s et al. (2010) reported compared to those from TNP. Maya-Corte that rats fed with ENP tortillas gained weight and had a highprotein efficiency ratio, suggesting that nutritional properties were improved by the ENP. Rodríguez et al. (2013) showed that degradation of the phenolic compounds and anthocyanins is rez et al. (2014) and Santiagoinhibited with ENP process. Bello-Pe Ramos et al. (2015a) demonstrated that tortillas made from ENP had high content of non-digestible carbohydrates resulting in a low glycemic index. For a large segment of the population in Mexico, tortilla is the most important source of protein, calcium and carbohydrates (Campas-Baypoli et al., 1999; Figueroa et al., 2003). Carbohydrates are the main fraction of tortillas with starch as its major component. It has been well stablished that a fraction of starch is resistant to digestive enzymes, passes through the small intestine and reaches the large intestine where it is fermented by colonic microflora, and it is referred as resistant starch (RS) (Asp et al., 1996). Readily digestible carbohydrates lead to a rapid increase in blood glucose levels and insulin secretion contributing to health conditions that increase the risk of diabetes. The Glycemic Index (GI) ranks carbohydrate-containing foods on how quickly and how much they elevate blood sugar levels. Foods with a low GI (<55) and high RS help to slow down the absorption of carbohydrates and prevent extreme fluctuations in blood glucose (Foster et al., 2002). The resistance of starch granules to the activity of amylases may be enhanced by annealing the starch. This consists of keeping the starch in water for a long period of time at a temperature lower than the gelatinisation temperature; such conditions are met during the steeping stage in the nixtamalisation process (Figueroa et al., 2013). Tortillas with high protein, lipids, fibre and resistant starch content can be produced by the ENP and CNP, which can provide nutraceutical benefits upon consumption, specifically a high content of non-starch polysaccharides which limits the access of starch rez hydrolyzing enzymes resulting in tortillas with low GI (Bello-Pe et al., 2014; Santiago-Ramos et al., 2015a). While there are few studies on Classic Nixtamalisation Process lez-Amaro et al., 2015), most au(CNP) (Pappa et al., 2010; Gonza thors have focused on TNP mainly on processing parameters as alkali concentration and cooking and steeping times (Trejomez et al., 1992; Rodríguez et al., 1996). Gonzalez et al., 1982; Go When wood ashes are used in CNP the resulting nixtamal, masa, flour and tortillas have a different profile in terms of mineral content (Pappa et al., 2010), dietary fibre and resistant starch compared to TNP and ENP. The different compounds (lime, wood ash, calcium salts) used in the nixtamalisation processes appear to have different effects on the starch, protein and the other components of maize grain and on the physical and functional characteristics of masa, flour and tortillas. Therefore, the objective of this study was to evaluate the effect of three different nixtamalisation processes on the chemical composition, resistant starch content and digestibility of tortillas tortillas and glycemic index measured in humans.
141
2. Materials and methods 2.1. Raw material Commercial hard endosperm white maize was obtained in a local market in Queretaro, Mexico. It was stored at 4 C until needed for processing. The lime [Ca(OH)2] and the salts calcium carbonate [CaCO3] and calcium propionate [Ca(CH3e CH3eCOO)2] of 97e99% purity food grade. Wood ash was of oak trees (Quercus agrifolia) from Oaxaca, Mexico. 2.2. Traditional nixtamalisation process (TNP) The TNP method of Campechano et al. (2012) was used. Briefly, 1 kg of maize was cooked with 2 L of water containing 1.0% (w/w) calcium hydroxide at 94 C for 30 min, the cooked grains (nixtamal) were steeped for 16 h to reach room temperature and the nixtamal ground in a stone mill to obtain fresh masa. The masa was passed through a flash dryer (CINVESTAV Mexico) at 260 C for 4 s to obtain dehydrated flour. Subsequently, this flour was ground in a hammer mill (Pulvex-200 Mexico D.F., Mexico) using a 0.5-mm mesh screen. 2.3. Ecological nixtamalisation process (ENP) The ecological process patented by Figueroa et al. (2011) was used in which lime was replaced by calcium salts to obtain whole grain flour. Briefly, 1 kg of maize was cooked with 2 L of water containing 1% (w/w) of calcium carbonate or calcium propionate for 30 min, the cooked grains were steeped for 16 h to reach room temperature. The nixtamal was ground in a stone mill to obtain masa. The masa was dehydrated in a flash dryer at 260 C (CINVESTAV Mexico) and ground in a mill (Pulvex-200 Mexico D.F. Mexico) using a hammer head and a 0.5-mm mesh screen (Campechano et al., 2012). 2.4. Classic nixtamalisation process (CNP) Two CNP were used containing different wood ashes concentration (1% and saturated 33%). 1 kg of maize was cooked with 4 L of water containing either 1% or 33% (saturated) wood ashes) at 94 C for 60 min and the cooked grains steeped for 16 h to reach room temperature. The nixtamal was ground in a stone mill to obtain fresh masa. The masa was processed in a flash dryer at 260 C for 4 s (CINVESTAV Mexico) to obtain dehydrated flour. Subsequently, this flour was ground in a mill (Pulvex-200 Mexico D.F. Mexico) using a hammer head and a 0.5-mm mesh screen. 2.5. Tortillas elaboration A sample of 250 g of dried flour was hydrated until obtain masa with adequately consistence. The masa was shaped into disks of 15 cm of diameter and 2 mm thick using a manual roller machine lez, Monterrey, NL, Me xico), and cooked on a griddle at (Casa Gonza 280 C for 17 s on the first side, 50 s on the second, and 34 s on the first side again to allow puffing. The tortillas were cooled at room temperature until they reached 30 C, and groups of five tortillas were packaged in polyethylene bags. 2.6. Pasting properties A Rapid Visco-Analyzer (RVA) (3C Model Newport Scientific PTY LTD, Sydney, Australia) was used to determine the pasting properties from viscoamylographic curves according to the method reez-Gonz ported by Narva alez et al. (2006).
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2.7. Thermal properties
3. Results and discussion
A differential scanning calorimeter (DSC) (Model 821 Mettler Toledo, Greifensee, Switzerland) equipped with a thermal analysis ezdata station was used following the method reported by Narva Gonz alez et al. (2006). Gelatinisation onset (To), peak (Tp) and final (Tf) temperatures, as well as enthalpy (DH), were computed automatically. Degree gelatinisation (%) was determined as follows (Baks et al., 2007).
3.1. Tortilla chemical properties from the nixtamalisation processes
Gelatinisation degreeð%Þ ¼ ð1 ðDHs DHn ÞÞ 100 Where DHs is the gelatinisation enthalpy of maize sample and DHn the gelatinisation enthalpy of unprocessed maize. 2.8. Chemical composition of tortillas Moisture, ash, fat, protein and crude fiber were analyzed according to the methods 44e19.01, 08e03.01, 30e25.01, 46e13.01, and 32e10.01 (AACC International, 2000). Carbohydrate content was calculated by difference. Total starch and resistant starch were analyzed by Megazyme kits assays based on methods 76e13.01 and 32e40.01 (AACC International, 2000). The mineral content (Ca, Fe, Mg, K) was determined by the method 40e75.01 using inductively coupled plasma spectroscopy (ICP) (AACC International, 2000). 2.9. X-ray diffraction The use of solvents and drying conditions during the isolation and purification of starch causes some changes in the X-ray diffraction patterns (Shogren et al., 2006). To avoid these problems, starches in maize, nixtamal and tortillas were characterized using X-ray diffraction, Rapid Visco-Analyzer (RVA) and Differential Scanning Calorimeter (DSC) without extracting the starch. All samples with similar particle size and moisture content of 7% were placed on a glass surface and scanned from 5 to 50 on the 2q scale using a Rigaku X-raydiffractometerDMAX-2100, which þ operates at 30 kV and 16 mA with a CuKa radiation of l ¼ 1.5405. The interplanar spacings (d) of the peaks were calculated using the Bragg equation nl ¼ 2 d sin q (Figueroa et al., 2013). 2.10. Glycemic index in vivo study Tortillas' glycemic index was determined in vivo according to Santiago-Ramos et al. (2015a). Briefly, five different tortilla samples were tested once by each of ten volunteers of age range 22e34 years old and BMI 22e25 kg/m2. Portions of tortillas containing 50 g of available carbohydrates were consumed by each volunteer over 10 min time period with 250 mL of water. Tortillas were ingested in random order on separate occasions in the morning after a 12 h overnight fast. Capillary finger-prick blood samples were taken from subjects at 0, 15, 30, 45, 60, 90, and 120 min after consuming the sample. Blood glucose concentrations were measured using OneTouch Ultra-Mini meter (Johnson & Johnson Miami FL, USA). Glycemic index was defined as the area under the blood glucose response curve for each tortilla treatment expressed as a percentage of the area after taking the same amount of carbohydrate as glucose. 2.11. Statistical analysis Comparison of means was performed by one-way analysis of variance followed by Duncan test analyzed by SAS software version 9.3 (SAS Institute Inc., Cary, NC).
Chemical composition of tortillas from the different nixtamalisation processes and treatments is reported in Table 1. There were no differences in the protein content of tortillas from the different nixtamalisation processes. Campechano et al. (2012) reported similar protein contents for TNP and ENP, ranging from 8.7 to 9.0%. Moisture content of fresh tortillas ranged from 46.3 to 51.8% with the highest value observed in ENP with CaCO3 and classic with saturated ash (data not shown). Overall, moisture content is similar with data reported by Campechano et al. (2012) and Pappa et al. (2010) for fresh tortillas elaborated with similar treatments. Differences in moisture content probably are related to water absorption during nixtamalisation and salts used. The fat content was significantly different between tortillas from the different nixtamalisation processes. Tortillas from ENP had higher fat values than tortillas made from CNP saturated ash. It is postulated that the alkaline pH in both the TPN and saturated ash CNP hydrolyzes the lipid ester linkages, and the free fatty acids are lost in the nejayote cooking liquor. The variation in tortilla fat among different nixtamalisation processes described here is similar to published values s et al. (2010). Campechano et al. (2012) also reby Maya-Corte ported a higher loss of lipids in the nejayote of the TNP compared to the ENP waste water. The ash content was higher in the CNP with saturated ash. However, there were important variations in crude fibre (Table 1). The EPN presented the highest crude fibre, explained by the retention of the pericarp and external layers of the maize grains during the different processing steps, which contain mainly fibre (cellulose, hemicelluloses). In the TNP, the pericarp and external layers are lost during the cooking, steeping and washing steps (Campechano et al., 2012). For this reason, the traditional tortillas and saturated wood ash CNP had lower values for crude fibre. Regarding dietary fibre there was a tendency to increase the total and insoluble fibre in EPN and CNP compared to TNP. The carbohydrate content in tortillas was within the values res et al. (2010). Values for ported for TNP and ENP by Maya-Corte total starch content ranged from 68.30 to 76.45%, and as expected lower values were found in tortillas from the ENP, as the higher concentration of crude fibre affected the total starch content (Table 1). The values for TNP tortillas are similar to the range re n-Villalobos et al. (2002). Total carbohydrate conported by Rendo tent of tortillas from CNP was similar to those reported by Pappa et al. (2010). In general, the total starch values in this study were within the rez et al., 2015) where range reported by several authors (Bello-Pe TNP and CNP saturated ash, had high total starch values. Differences in tortilla total starch can be explained by the loss of pericarp and other maize kernel outer layers in the cooking liquor during the nixtamalisation process that affected the percentage of total material recovered. 3.2. Minerals Tortillas are a good source of Ca, Fe, Mg and K, all of which are important micronutrients in the diet (Table 2). An important contribution from the nixtamalisation process is the significant increase in mineral content especially Ca and Fe, in maize products like tortillas compared to the mineral content of raw maize (Table 2). Figueroa et al. (2003) reported that tortillas provided 46% of the daily requirement of Ca when the tortilla consumption was about 325 g/day. A study comparing the properties of lime vs. wood ash processing found that the latter one provides 14.4 times the
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Table 1 Chemical composition of tortillas from different nixtamalisation processesa,b. Process
Protein (%)
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C₂H₅COO)₂ Classic 1% ash Classic saturated ash
8.69 8.61 8.30 8.08 8.21
± ± ± ± ±
0.6a 0.8a 0.1a 0.2a 0.4a
Fat (%) 3.15 3.77 4.23 3.41 2.26
± ± ± ± ±
Crude fibre (%)
Ash (%) 0.0b 0.03b 0.49a 0.51b 0.20c
1.30 1.36 1.36 1.27 2.76
± ± ± ± ±
0.04b 0.04b 0.08b 0.12b 0.08a
2.46 2.69 2.60 2.40 1.80
± ± ± ± ±
0.02c 0.02a 0.11b 0.01c 0.04d
IF (%) 9.83 10.86 12.28 13.40 13.23
SF (%) ± ± ± ± ±
0.29c 0.01b 0.02b 0.36a 0.51a
1.94 2.70 1.74 1.67 2.33
± ± ± ± ±
Carbohydratec (%)
TDF (%) 0.05c 0.28a 0.27c 0.12c 0.23b
11.78 13.60 14.01 15.08 15.56
± ± ± ± ±
0.34c 0.28b 0.25b 47a 0.28a
84.40 83.56 83.49 84.84 84.97
± ± ± ± ±
0.6 ab 0.34b 0.42b 0.45a 0.20a
Total starch (%) 74.85 68.30 72.30 73.40 76.45
± ± ± ± ±
0.21b 0.14e 0.14d 0.28c 0.21a
IF ¼ Insoluble fibre; SF ¼ soluble fibre; TDF ¼ total dietary fibre. a Means ± SD. Means with a different letter within the same column are statistically different (P < 0.05) (n ¼ 2). b Data reported on dry basis (w/w). c Carbohydrate content calculated by difference.
level of Fe, 15.0 times the level of Zn, twice as much Mg and 8.4 times K compared to the lime process (Pappa et al., 2010). A similar trend of the mineral content was observed in the present study (Table 2). In contrast, tortillas from TNP process had higher Ca content because calcium content in lime [Ca(OH)2] is two times higher than calcium salts and wood ashes (Table 2). For Fe, tortillas saturated with wood ash had the highest content; this mineral is one of the most limited micronutrients in the daily Mexican diet. Overall, Mg and K in tortillas decreased compared to raw maize. This could be explained in part by the loss of maize germ where K and Mg are found as salts of phytic acid (Bressani et al., 1990). 3.3. Thermal and rheological properties of native and annealed starch in nixtamal and tortilla samples from different nixtamalisation processes For the viscoamylographic RVA tortillas profiles, the CNP saturated wood ashes showed the highest peak viscosity value, this behavior suggests that with this process the starch granules have more interactions with maize chemical components, followed by TNP (Fig. 1). The present data agrees with others authors (Gujral et al., 2008) who indicated that in wheat the addition of ashes from incinerated wheat (1%e2%) increased the peak viscosity of the wheat flours. The same authors indicated that during the incineration process to obtain ash, the form of mineral constituents changed to oxides, sulfates, phosphates, chlorides, and carbonates. This result indicates that added ash may induce cross-links or ionic interactions among the flour components, mainly with the proteins, consequently increasing viscosity (Gujral et al., 2008; Santiago-Ramos et al., 2015b). Regarding functionality, little evidence is available concerning the effects of ash on flour. In baking and pasta applications, higher ash often plays a positive role. First, the extra minerals may result in a stronger dough and a finished product with more nutrition and better color. The present research also showed that the tortilla from ash presented mineral content important from the nutritional point of view (Table 2) but also good textural properties (data not shown). Santiago-Ramos et al. (2015b)
indicated that an increase in Ca(OH)2 concentration and consequently an increase of pH values of cooking solutions and nixtamal starch induced an increase of peak viscosity. The other two ENP variants and CNP with 1.0% of ash had a similar viscosity profiles. For tortillas samples peak viscosities were: 1193 cP for CNP saturaded wood ashes, 773 cP for TNP, 624 cP for ENP 1.0% carbonate and ENP with Ca-propionate 1.0% and 595 cP for CNP 1.0%. Those differences in viscosity indicate that pasting curves depends to the nixtamalisation process, and those parameters are affected by processing conditions. Final viscosity (FV) is related with cooling, this trend indicates that the elements present in the flour are associated during the retrogradation step and related to the flour quality during storage. CNP 1% and ENP with both salts had the lower FV it indicates a higher stability of starch to the cooking and cooling providing a softer tortillas for re-heating (Fig. 1).
Fig. 1. Typical RVA viscoeamylographic profile for tortillas prepared from different processes. A. Classic with 1% wood ash; B. Classic process with saturated wood ash; C. Ecological with calcium carbonate 1%.; D. Traditional with calcium hydroxide 1%; E. Ecological with calcium propionate 1%.
Table 2 Mineral composition of tortillas from different nixtamalisation processesa. Process
Calcium (mg/100 g)
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)₂ Classic 1% Ash Classic saturated Ash Wood ashes Lime [Ca(OH)2] Calcium propionate Calcium carbonate Raw maize
289.6 190.2 155.9 134.8 704.0 21,929 52,200 15,663 11,969 22.95
a
± ± ± ± ± ± ± ± ± ±
4.94a 2.75bc 1.76c 13.43e 86.26b 27.50 14.06 6.70 3.60 0.15
Iron (mg/100 g) 4.3 7.0 6.3 5.1 9.5 544.5 9.0 3.9 10.0 4.0
± ± ± ± ± ± ± ± ± ±
0.0e 0.01b 0.04c 0.04d 0.04a 8.40 0.52 0.37 0.07 0.12
Magnesium (mg/100 g)
Potasium (mg/100 g)
Zinc (mg/100 g)
138.3 ± 1.98b 146.3 ± 1.50c 148.4 ± 6.92d 149.8 ± 9.13a 196.0 ± 6.43e 907.70 ± 3.30 173.25 ± 0.98 __ __ 111.69 ± 0.12
263.7 ± 5.38c 275.4 ± 2.96b 281.8 ± 5.15d 256.2 ± 22.13e 310.2 ± 7.63a 2379.88 ± 15.2 310.1 ± 0.76 180 ± 1.47 __ 222.4 ± 0.63
3.1 3.4 4.6 3.7 4.0 2.5 5.35 22.5 2.0 2.15
Means (n ¼ 3) followed by a different letter within the same column are statistically different (P < 0.05). SD ¼ standard deviation.
± ± ± ± ± ± ± ± ± ±
0.35b 0.55b 0.50a 0.30 ab 0.28 ab 0.7 0.85 2.12 0.1 0.09
± ± ± ± ± 0.15 0.24 0.52 0.41 0.56 117.42 108.05 120.21 120.45 117.83 51.68 50.75 51.93 51.59 52.26 1.9a 2.03a 0.22a 0.81a 0.24a ± ± ± ± ± 44.47 42.90 44.75 43.67 45.02
To, Tp and Tf are onset; peak and final temperature, respectively. DH ¼ Enthalpy; DG ¼ Degree of gelatinisation; SD ¼ standard deviation. (I) Retrogradation (II) Amylose lipid complex. a Means ± SD followed by the same letter in the same column within the same product are not significantly different (P < 0.05).
109.50 105.70 105.07 103.26 103.55 92.55 98.77 85.98 91.43 86.61 e e e e e e e e e e e e e e e e e e e e e e e e e 0.88 1.24 0.63 0.48 0.39 59.79 60.33 60.34 60.50 61.21
e e e e e e e e e e
± ± ± ± ± e e
Maize Nixtamal Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C₂H₅COO)₂ Classic 1% ash Classic saturated ash Tortillas Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)2 Classic 1% ash Classic saturated ash
0.84a 0.49a 0.47a 0.24a 0.22a
e e e e e
± ± ± ± ±
0.54a 1.15a 1.35a 0.37a 0.69a
e e e e e
± ± ± ± ±
0.09 ab 0.18a 0.18bc 0.03bc 0.01c
63.735 66.53 64.52 68.44 66.18
± ± ± ± ±
0.23a 2.86 a 1.19a 0.33a 0.20a
70.55 72.47 73.10 75.25 73.85
± ± ± ± ±
0.23a 3.41a 0.21a 0.40a 0.37a
81.48 82.60 84.71 89.06 85.55
± ± ± ± ±
0.38c 1.29c 0.85b 0.33a 0.49b
4.11 6.26 3.36 6.63 4.12
± ± ± ± ±
0.40b 0.10a 0.18b 0.69a 0.53b
43.55 ± 0.06a 14.13 ± 0.01b 53.85 ± 0.02a 9.05 ± 0.01b 43.42 ± 0.07a
e e e e e
± ± ± ± ±
0.35b 0.12a 0.11e 0.15c 0.11d
e e e e e
± ± ± ± ±
0.03a 0.11b 0.09b 0.04b 2.04b
e e e e e
± ± ± ± ±
0.14 0.15 0.06 0.13 0.35
e e e e e
e e e e 0 7.29 ± 0.40 80.40 ± 0.14 70.37 ± 0.18 63.16 ± 0.33 e
To(G) ( C)
DH(I) (J/g) Tf(I) ( C) Tp(I) ( C)
Tortillas made with the TNP had 2.99% resistant starch content, n-Villalobos et al. a value consistent with reports from Rendo (2002) and Campas-Baypoli et al. (1999). There were no significant differences in RS between the nixtamalisation processes, except for saturated ash CNP, which showed lower value (Table 4). The amount of RS increased significantly when the maize was transformed into nixtamal and into tortillas, as result of the heat treatments that the grain is subjected to during the process steps. These treatments promote the interaction of the starch with other components (proteins, lipids or itself) making it less susceptible to enzyme hydrolysis (Saura-Calixto et al., 1993). Santiago-Ramos et al. (2015a) reported a range of 2.8e3.8% of resistant starch in tortillas obtained from ecologic however, those differences are in function of the different concentrations of calcium salts used.
To(I) ( C)
3.5. Resistant starch and glycemic index
Table 3 Thermal properties of nixtamal and tortillas from different nixtamalisation processes.a
Native maize showed an A type X-ray diffraction pattern, with peaks at approximately 15 , 17 and 23.4 (angle 2q), typical for cereal starches (Zobel, 1988). The A-type pattern is lost when maize is submitted to the nixtamalisation process and it is substituted by a V-type pattern denoting the formation of amylose-lipid complexes (Fig. 2). The latter one exhibits an additional peak at angle 2q ¼ 20 , which can be interpreted as a Vform due to the presence of these amylose-lipid complexes €ssler et al., 2006). After tortilla preparation and with the (Fa combination of water and temperature, amylose-lipid complex formation is stronger compared to the pattern of nixtamal. In Fig. 2, X-rays diffraction patterns for the five nixtamalisation processes evaluated in this study are shown. After nixtamalisation the maize lost part of the typical crystalline structure. The A-type was replaced by V-type in tortillas and nixtamal. The process that showed the highest degree of replacement was the saturated wood ash CNP.
Tp(G) ( C)
3.4. X-ray diffraction
e
Tf(G) ( C)
DH(G) (J/g)
DG (%)
To(II) ( C)
Tp(II) ( C)
Tf (II) ( C)
DH(G) (J/g)
Table 3 shows the thermal properties of maize, nixtamal and tortillas demonstrating significant differences in the majority of the parameters. The increase of onset, peak and final temperature of starch gelatinisation in all the nixtamalisation processes compared with native starch in maize is an evidence of starch annealing. These results are in agreement with previous reports that indicated the increase thermal properties was caused by starch modification in the nixtamalisation process (Campas n-Villalobos Baypoli et al., 1999; Figueroa et al., 2013; Rendo et al., 2002). The alteration within the starch crystallites of nixtamalised maize kernels might explain the increase in gelatinisation temperatures of annealed nixtamal starch samples compared to the native maize starch. In contrast, there was a reduction in entalphy from native maize to nixtamal, which can be attributed to starch gelatinisation. The enthalpy of native maize starch (7.290 J/g) was reduced between 3.365 and 6.630 J/g in annealed nixtamal. Gelatinisation was higher for ENP with Calcium propionate and CNP with saturated ash. Baks et al. (2007) mentioned that a typical gelatinisation endotherm of starch occurs in the thermogram between 51 and 76 C (Table 3). However, a shift of the gelatinisation endotherm of tortillas starch can be seen at lower temperatures compared to native starch. Table 3 shows that the transition endotherms in tortillas occur between 37 and 65 C. These values agree with the reports of García-Rosas et al. (2009) using TNP and SantiagoRamos et al. (2015a) with the TNP and ENP found the thermal transition in tortillas with temperature range of 23.4e64.0 C attributed it to the dissociation of retrograded amylopectin.
0.01d 0.04c 0.03a 0.02b 0.01a
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Product
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Fig. 2. X-ray diffraction patterns from the different nixtamalisation processes: A. Traditional with Ca(OH)2; B. Classic saturated wood ash, C. Ecological with 1% CaCO3, D. Ecological with 1% Ca(C2H5COO)2. Patterns are shifted along the linear intensity axis for clarity by adding constants of 1000 cps to each pattern except, for raw maize that maintains the original counts per second (cps) value.
Glycemic index for different products are shown in Table 4. Fifteen minutes after the tortillas were ingested, the lowest glucose values were seen for tortillas made with the 1% wood ash CNP, and the highest value for tortillas made from the saturated wood ash CNP. The GI was affected by the chemical composition of the tortillas and the amount of resistant starch present (Table 4). A low glycemic response is considered beneficial from a nutritional point of view, especially for individuals suffering from impaired glucose tolerance. Table 4 shows that the four non-traditional processes used in this study gave tortillas with a lower GI than traditional tortillas. According to the classification of GI by Foster et al. (2002), tortillas from the traditional process were found to be a food with intermediate GI. Consequently, tortillas made from the 1% calcium propionate ENP and the 1% wood ash CNP can be classified as low GI foods. These results are in agreement with those reported by Santiago-Ramos et al. (2015a) for traditional tortillas. 4. Conclusion
composition, influencing minerals, functional quality and nutritional properties. The nixtamalisation and salts used may inhibit the enzyme activity or increase the resistant starch content in the majority of tortillas. Tortillas made with ecological nixtamalisation process had lower Glycemic Index than tortillas made with traditional nixtamalisation process, however Classic nixtamalisation process with 1% ash had the lowest Glycemic Index and the highest iron content in tortillas. Tortillas elaborated with the Classic nixtamalisation process 1% ash and ENP with Ca propionate could be a healthier option for tortilla consumption, due to nutritional advantages. Acknowledgments Rosa María Mariscal-Moreno and David Santiago-Ramos thank the CONACYT for the Ph. D. scholarships. We thank Rosa María lez-Amaro from ECOSUR, Martín Adelaido Herna ndezGonza nica Flores-Casamayor from CinvestavLandaverde, and Vero taro for their technical support. Quere
Different nixtamalisation processes affected chemical tortilla References Table 4 Glycemic index for tortillas made from the different nixtamalisation processesa. Process for tortilla preparation
Resistant starch (%)
Glycemic Index
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)2 Classic 1% ash Classic saturated ash Glucose Maize
2.99 ± 0.11a 3.06 ± 0.19a 2.79 ± 0.12a 2.96 ± 0.11a 2.15 ± 0.09b e 0.86e0.93
70.0 ± 2.11b 60.0 ± 1.45d 37.4 ± 0.87e 29.2 ± 3.02f 69.6 ± 0.93 c 100.00a
a Means ±SD followed by the same letter in the same column are not significantly different (P < 0.05). SD ¼ standard deviation.
AACC International, 2000. Approved Methods of Analysis. Method 44 19.01 Moisture; Method 08e03.01 Ash; Method 46-16.01 Crude-Protein; Method 30-25.01 Fat; Method 32-10.01 Crude fiber; Method 32-40.01 Resistant Starch; Method 76-13.01 Total Starch; Method 40-75.01 Mineral content, eleventh ed. AACC International, St. Paul, MN. Asp, N.G., Van-Amelsvoort, J.M.M., Hautvast, J.G.A.J., 1996. Nutritional implications of resistant starch. Nutr. Res. Rev. 9, 1e31. Baks, T., Ngene, I.S., Van-Soest, J.J.G., Janssen, A.E.M., Boom, R.M., 2007. Comparison of methods to determine the degree of gelatinisation for both high and low starch concentrations. Carbohydr. Polym. 67, 481e490. rez, L.A., Flores-Silva, P.C., Agama-Acevedo, E., Figueroa-Ca rdenas, J.D., Bello-Pe pez-Valenzuela, J.A., Campanella, O.H., 2014. Effect of the nixtamalization Lo with calcium carbonate on the indigestible carbohydrate content and starch digestibility of corn tortilla. J. Cereal Sci. 60, 421e425.
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rez, L.A., Flores-Silva, P.C., Camelo-Me ndez, G.A., Paredes-Lo pez, O., Bello-Pe Figueroa, J.D.C., 2015. Effect of the nixtamalization process on the dietary fiber content, starch digestibility, and antioxidant capacity of blue maize tortilla. Cereal Chem. 92, 265e270. Bressani, R., Benavides, V., Acevedo, E., Ortiz, M.A., 1990. Changes in selected nutrient content and in protein quality of common and quality protein maize during tortilla preparation. Cereal Chem. 67, 515e518. nez, S.J.S., Campechano, C.E.M., Figueroa, J.D.C., Ar ambula, V.G., Martínez, F.H.E., Jime Luna, B.J.G., 2012. New ecological nixtamalisation process for tortilla production and its impact on the chemical properties of whole corn flour and wastewater effluents. Int. J. Food Sci. Technol. 47, 564e571. Campas-Baypoli, O.N., Rosas-Burgos, E.C., Torres-Ch avez, P.I., Ramirez-Wong, B., Serna-Saldívar, S.O., 1999. Physicochemical changes of starch during maize tortilla production. Starch/Starke 5, 173e177. €ssler, C., Arrigoni, E., Venema, K., Hafner, V., Brouns, F., Amado , R., 2006. DiFa gestibility of resistant starch containing preparations using two in vitro models. Eur. J. Nutr. 45, 445e453. Figueroa, J.D.C., Acero, M.G., Vasco, N.L., Lozano, A.G., Flores, L.M.A., 2003. Nutritional quality of nixtamal tortillas fortified with vitamins and soy proteins. Int. J. Food Sci. Nutr. 54, 189e200. gico de Figueroa, J.D.C., Rodríguez-Chong, A., Veles-Medina, J.J., 2011. Proceso ecolo n de harinas, masa y tortillas integrales. 15 de nixtamalizacion para la produccio agosto de 2011. Patente mexicana número 289339 (in Spanish). les, J.J.M., Herna ndez, L.M.A., Arago n, C.F., Gayta n, M.M., Figueroa, J.D.C., Ve Ch avez, M.E., Palacios, N., Willcox, M., 2013. Effect of annealing from traditional nixtamalisation process on the microstructural, thermal, and rheological properties of starch and quality of pozole. J. Cereal Sci. 58, 457e464. Foster, P.,R., Holt, S.H.A., Brand-Miller, J.C., 2002. International table of glycemic index and glycemic load values. Am. J. Clin. Nutr. 76, 5e56. rez, A., Yee-Madeira, H., Ramos, G., Flores-Morales, A., García-Rosas, M., Bello-Pe Mora-Escobedo, R., 2009. Resistant starch content and structural changes in maize (Zea mays) tortillas during storage. Starch/St€ arke 61, 414e421. mez, M.H., Lee, J.K., McDonough, C.M., Waniska, R.D., Rooney, L.W., 1992. Corn Go starch changes during tortilla and tortilla chip processing. Cereal Chem. 69, 275e279. lez-Amaro, R.M., Figueroa, J.D.C., Perales, H., Santiago-Ramos, D., 2015. Maize Gonza races on functional and nutritional quality of tejate:A maize-cacao beverage. LWT-Food Sci. Technol. 63, 1008e1015. Gujral, H.S., Park, S.J., Baik, B.-K., 2008. Effect of added minerals on pasting of partial waxy wheat flour and starch and on noodle making properties. Cereal Chem. 85, 97e101. Katz, S.H., Hediger, M.L., Valleroy, L.A., 1974. Traditional maize proccessing tecniques in the new world. Science 184, 765e773.
s, D.C., Figueroa-Ca rdenas, J.D., Garnica-Romo, M.G., CuevasMaya-Corte s-Martínez, R., Ve les-Medina, J.J., Martínez-Flores, H.E., Villanueva, R.A., Corte 2010. Whole-grain corn tortilla prepared using an ecological nixtamalisation process and its impact on the nutritional value. Int. J. Food Sci. Technol. 45, 23e28. ez-Gonza lez, D.E., Figueroa, J.D.C., Taba, S., Rinco n, F.S., 2006. Kernel microNarva structure of Latin American races of maize and their thermal and rheological properties. Cereal Chem. 83, 605e610. Pappa, M.R.P., Palacios, P., Bressani, R., 2010. Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics. Plant Foods Hum. Nutr. 65, 130e135. n-Villalobos, R., Bello-Pe rez, L.A., Osorio-Díaz, P., Tovar, J., Paredes-Lopez, O., Rendo 2002. Effect of storage time on in vitro digestibility and resistant starch content in nixtamal, masa and tortilla. Cereal Chem. 79, 340e344. n ~ez-Limo n, M., Alvarado-Gil, J.J., Vargas, H., Sa nchez-Sinencio, F., Rodríguez, M.E., Ya Figueroa, J.D.C., Martínez-Bustos, F., Martínez-Montes, J.L., Gonz alezHern andez, J., Silva, M.D., Miranda, L.C.M., 1996. Influence of the structural changes during alkaline cooking on the thermal, rheological, and dielectrical properties of corn tortillas. Cereal Chem. 73, 593e600. ndez, L.L.L., 2013. Nutraceutical Rodríguez, M.L.I., Figueroa, J.D.C., Ramos, M.G., Me properties of flour and tortillas made with an ecological nixtamalization process. J. Food Sci. 78, 1529e1534. Santiago-Ramos, D., Figueroa, J.D.C., Veles-Medina, J.J., Mariscal-Moreno, R.M., mez, M., Gayta n-Martínez, M., MoralesReynoso-Camacho, R., Ramos-Go nchez, E., 2015a. Resistant starch formation in tortillas from an ecological Sa nixtamalization process. Cereal Chem. 92, 185e192. Santiago-Ramos, D., Figueroa, J.D.C., Veles-Medina, J.J., Reynoso-Camacho, R., mez, M., Gayta n-Martínez, M., Morales-Sa nchez, E., 2015b. Effect of Ramos-Go annealing and concentration of calcium salts on thermal and rheological properties of maize starch during ecological nixtamalization process. Cereal Chem. 92. http://dx.doi.org/10.1094/CCHEM-12-14-0258-R. ~ i, I., Bravo, L., Man ~ as, E., 1993. Resistant starch in foods: Saura-Calixto, F., Gon modified method for dietary fiber residues. Food Sci. 58, 642e643. Shogren, R.L., Fanta, G.F., Felker, F.C., 2006. X-ray diffraction study of crystal transformations in spherulitic amylose/lipid complexes from jet-cooked starch. Carbohydr. Polym. 64, 444e451. Trejo-Gonz alez, A., Feria-Morales, A., Wild-Altamirano, C., 1982. The role of lime in the alkaline treatment of corn for tortilla production. In: Feeney, R.E., Whitaker, J.R. (Eds.), Modifications of Proteins: Food, Nutritional and Pharmacological Aspects. Advances in Chemistry. American Chemical Society, Washington, DC, pp. 245e263. Zobel, H.F., 1988. Starch crystal transformation and their industrial importance. €rke 40, 1e7. Starch/Sta
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The effect of different nixtamalisation processes on some physicochemical properties, nutritional composition and glycemic index Rosa María Mariscal Moreno a, J.D.C. Figueroa a, *, David Santiago-Ramos b, nez Sandoval a, Patricia Rayas-Duarte c, nimo Ara mbula Villa a, Sergio Jime Gero a ctor Eduardo Martínez Flores d Juan Ve les-Medina , He Jose CINVESTAV-Unidad Quer etaro, Libramiento Norponiente No. 2000, Fracc Real de Juriquilla, Quer etaro, Qro 76230, Mexico noma de Quer PROPAC, Universidad Auto etaro. Cerro de las Campanas S/N, Col. Las Campanas, Quer etaro, Quer etaro C. P. 76010, Mexico c Robert M. Kerr Food & Agricultural Products Center, Biochemistry and Molecular Biology, Oklahoma State University, 123 FAPC, Stillwater, OK 74078-6055, USA d s de Hidalgo, Tzintzuntzan 173, Col. Matamoros, Morelia Mich., Mexico Facultad de Químico Farmacobiología, Universidad Michoacana de San Nicola a
b
a r t i c l e i n f o
a b s t r a c t
Article history: Received 24 March 2015 Received in revised form 24 June 2015 Accepted 28 June 2015 Available online 2 July 2015
The objective was to evaluate corn tortillas made from three nixtamalisation processes including Traditional with lime (TNP), Classic with ashes (CNP) and Ecological with Ca salts (ENP), and their effect on mineral content (Ca, Fe, K, and Mg), chemical composition, resistant starch (RS), and glycemic index (GI). ENP with calcium propionate and carbonate had higher fat values than tortillas from CNP. EPN and CNP presented the higher dietary fibre, explained by the highest pericarp retention. In TNP the pericarp and external layers were lost during the cooking, steeping and washing steps and had lower crude fiber. The amount of RS increased in nixtamal and tortillas independently of nixtmalisation processes. Annealing of starch was shown by the increase of onset, peak and final gelatinisation temperatures in nixtamalised products compared with untreated maize. Gelatinisation was higher for calcium propionate ENP and 1% ash CNP. Native maize changed from A-type to V-type pattern in nixtamalised products denoting the formation of amylose-lipid complexes. Overall, nixtamalisation processes and salts used increased RS. The GI was affected by chemical composition in tortillas and amount of RS. Tortillas made from ENP Ca propionate and ENP 1% ash CNP can be classified as low GI foods. © 2015 Elsevier Ltd. All rights reserved.
Keywords: Nixtamalisation Resistant starch Chemical composition Glycemic index
1. Introduction Maize for human consumption is processed in Mexico following the pre-Columbian technique known as nixtamalisation which is a process whereby maize is boiled in water containing Ca(OH)2 (lime), the nixtamal (cooked maize), obtained is steeped overnight, washed and ground to obtain masa. The masa can be used immediately for tortillas, or dried and grounded to produce dry masa flour (nixtamalised flour). The nixtamalisation process is critical in enhancing the nutritional value of maize and is used to make several products (tortillas, tamales, pozole, atoles, totopos, snacks,
* Corresponding author. E-mail address: jfi[email protected] (J.D.C. Figueroa). http://dx.doi.org/10.1016/j.jcs.2015.06.016 0733-5210/© 2015 Elsevier Ltd. All rights reserved.
tacos, tostadas, and nachos) which are staple foods in Mexico, Central America and widely consumed in United States (Campechano et al., 2012; Figueroa et al., 2013). Archeological evidence suggests that the ancient nixtamalisation process (Classic Nixtamalisation Process, CNP) used by the Mayas in the Preclassic period (1200-250 B C.) consisted in cooking maize with wood ashes (Katz et al., 1974). Later the Aztecs, settled in central Mexico around 1325 A.D. substituted ashes for lime, though it is not clear exactly when, creating the Traditional Nixtamalisation Process (TNP) that is remained used in present commercial operations. There is a need to improve the sustainability of the TNP which uses large volume of water producing high dry matter losses (3e15%) in the nixtamal during the cooking and washing steps (Campechano et al., 2012). During the mentioned processing
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steps nutrients are lost, including vitamins, fat, protein, dietary s et al., fibre and some biological active compounds (Maya-Corte 2010; Campechano et al., 2012; Rodríguez et al., 2013). In addition, the nejayote (cooking solution) is an environmental pollutant due to its high alkalinity which also damages the processing equipment. Recently, an Ecological Nixtamalisation Process (ENP) patented by Figueroa et al. (2011) addresses some of challenges of environmental and nutritional effects. The ENP replaces calcium hydroxide with commercially available calcium salts (e. g. calcium propionate and calcium carbonate). The masa and tortillas made from ENP had improved appearance and sensory properties s et al. (2010) reported compared to those from TNP. Maya-Corte that rats fed with ENP tortillas gained weight and had a highprotein efficiency ratio, suggesting that nutritional properties were improved by the ENP. Rodríguez et al. (2013) showed that degradation of the phenolic compounds and anthocyanins is rez et al. (2014) and Santiagoinhibited with ENP process. Bello-Pe Ramos et al. (2015a) demonstrated that tortillas made from ENP had high content of non-digestible carbohydrates resulting in a low glycemic index. For a large segment of the population in Mexico, tortilla is the most important source of protein, calcium and carbohydrates (Campas-Baypoli et al., 1999; Figueroa et al., 2003). Carbohydrates are the main fraction of tortillas with starch as its major component. It has been well stablished that a fraction of starch is resistant to digestive enzymes, passes through the small intestine and reaches the large intestine where it is fermented by colonic microflora, and it is referred as resistant starch (RS) (Asp et al., 1996). Readily digestible carbohydrates lead to a rapid increase in blood glucose levels and insulin secretion contributing to health conditions that increase the risk of diabetes. The Glycemic Index (GI) ranks carbohydrate-containing foods on how quickly and how much they elevate blood sugar levels. Foods with a low GI (<55) and high RS help to slow down the absorption of carbohydrates and prevent extreme fluctuations in blood glucose (Foster et al., 2002). The resistance of starch granules to the activity of amylases may be enhanced by annealing the starch. This consists of keeping the starch in water for a long period of time at a temperature lower than the gelatinisation temperature; such conditions are met during the steeping stage in the nixtamalisation process (Figueroa et al., 2013). Tortillas with high protein, lipids, fibre and resistant starch content can be produced by the ENP and CNP, which can provide nutraceutical benefits upon consumption, specifically a high content of non-starch polysaccharides which limits the access of starch rez hydrolyzing enzymes resulting in tortillas with low GI (Bello-Pe et al., 2014; Santiago-Ramos et al., 2015a). While there are few studies on Classic Nixtamalisation Process lez-Amaro et al., 2015), most au(CNP) (Pappa et al., 2010; Gonza thors have focused on TNP mainly on processing parameters as alkali concentration and cooking and steeping times (Trejomez et al., 1992; Rodríguez et al., 1996). Gonzalez et al., 1982; Go When wood ashes are used in CNP the resulting nixtamal, masa, flour and tortillas have a different profile in terms of mineral content (Pappa et al., 2010), dietary fibre and resistant starch compared to TNP and ENP. The different compounds (lime, wood ash, calcium salts) used in the nixtamalisation processes appear to have different effects on the starch, protein and the other components of maize grain and on the physical and functional characteristics of masa, flour and tortillas. Therefore, the objective of this study was to evaluate the effect of three different nixtamalisation processes on the chemical composition, resistant starch content and digestibility of tortillas tortillas and glycemic index measured in humans.
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2. Materials and methods 2.1. Raw material Commercial hard endosperm white maize was obtained in a local market in Queretaro, Mexico. It was stored at 4 C until needed for processing. The lime [Ca(OH)2] and the salts calcium carbonate [CaCO3] and calcium propionate [Ca(CH3e CH3eCOO)2] of 97e99% purity food grade. Wood ash was of oak trees (Quercus agrifolia) from Oaxaca, Mexico. 2.2. Traditional nixtamalisation process (TNP) The TNP method of Campechano et al. (2012) was used. Briefly, 1 kg of maize was cooked with 2 L of water containing 1.0% (w/w) calcium hydroxide at 94 C for 30 min, the cooked grains (nixtamal) were steeped for 16 h to reach room temperature and the nixtamal ground in a stone mill to obtain fresh masa. The masa was passed through a flash dryer (CINVESTAV Mexico) at 260 C for 4 s to obtain dehydrated flour. Subsequently, this flour was ground in a hammer mill (Pulvex-200 Mexico D.F., Mexico) using a 0.5-mm mesh screen. 2.3. Ecological nixtamalisation process (ENP) The ecological process patented by Figueroa et al. (2011) was used in which lime was replaced by calcium salts to obtain whole grain flour. Briefly, 1 kg of maize was cooked with 2 L of water containing 1% (w/w) of calcium carbonate or calcium propionate for 30 min, the cooked grains were steeped for 16 h to reach room temperature. The nixtamal was ground in a stone mill to obtain masa. The masa was dehydrated in a flash dryer at 260 C (CINVESTAV Mexico) and ground in a mill (Pulvex-200 Mexico D.F. Mexico) using a hammer head and a 0.5-mm mesh screen (Campechano et al., 2012). 2.4. Classic nixtamalisation process (CNP) Two CNP were used containing different wood ashes concentration (1% and saturated 33%). 1 kg of maize was cooked with 4 L of water containing either 1% or 33% (saturated) wood ashes) at 94 C for 60 min and the cooked grains steeped for 16 h to reach room temperature. The nixtamal was ground in a stone mill to obtain fresh masa. The masa was processed in a flash dryer at 260 C for 4 s (CINVESTAV Mexico) to obtain dehydrated flour. Subsequently, this flour was ground in a mill (Pulvex-200 Mexico D.F. Mexico) using a hammer head and a 0.5-mm mesh screen. 2.5. Tortillas elaboration A sample of 250 g of dried flour was hydrated until obtain masa with adequately consistence. The masa was shaped into disks of 15 cm of diameter and 2 mm thick using a manual roller machine lez, Monterrey, NL, Me xico), and cooked on a griddle at (Casa Gonza 280 C for 17 s on the first side, 50 s on the second, and 34 s on the first side again to allow puffing. The tortillas were cooled at room temperature until they reached 30 C, and groups of five tortillas were packaged in polyethylene bags. 2.6. Pasting properties A Rapid Visco-Analyzer (RVA) (3C Model Newport Scientific PTY LTD, Sydney, Australia) was used to determine the pasting properties from viscoamylographic curves according to the method reez-Gonz ported by Narva alez et al. (2006).
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2.7. Thermal properties
3. Results and discussion
A differential scanning calorimeter (DSC) (Model 821 Mettler Toledo, Greifensee, Switzerland) equipped with a thermal analysis ezdata station was used following the method reported by Narva Gonz alez et al. (2006). Gelatinisation onset (To), peak (Tp) and final (Tf) temperatures, as well as enthalpy (DH), were computed automatically. Degree gelatinisation (%) was determined as follows (Baks et al., 2007).
3.1. Tortilla chemical properties from the nixtamalisation processes
Gelatinisation degreeð%Þ ¼ ð1 ðDHs DHn ÞÞ 100 Where DHs is the gelatinisation enthalpy of maize sample and DHn the gelatinisation enthalpy of unprocessed maize. 2.8. Chemical composition of tortillas Moisture, ash, fat, protein and crude fiber were analyzed according to the methods 44e19.01, 08e03.01, 30e25.01, 46e13.01, and 32e10.01 (AACC International, 2000). Carbohydrate content was calculated by difference. Total starch and resistant starch were analyzed by Megazyme kits assays based on methods 76e13.01 and 32e40.01 (AACC International, 2000). The mineral content (Ca, Fe, Mg, K) was determined by the method 40e75.01 using inductively coupled plasma spectroscopy (ICP) (AACC International, 2000). 2.9. X-ray diffraction The use of solvents and drying conditions during the isolation and purification of starch causes some changes in the X-ray diffraction patterns (Shogren et al., 2006). To avoid these problems, starches in maize, nixtamal and tortillas were characterized using X-ray diffraction, Rapid Visco-Analyzer (RVA) and Differential Scanning Calorimeter (DSC) without extracting the starch. All samples with similar particle size and moisture content of 7% were placed on a glass surface and scanned from 5 to 50 on the 2q scale using a Rigaku X-raydiffractometerDMAX-2100, which þ operates at 30 kV and 16 mA with a CuKa radiation of l ¼ 1.5405. The interplanar spacings (d) of the peaks were calculated using the Bragg equation nl ¼ 2 d sin q (Figueroa et al., 2013). 2.10. Glycemic index in vivo study Tortillas' glycemic index was determined in vivo according to Santiago-Ramos et al. (2015a). Briefly, five different tortilla samples were tested once by each of ten volunteers of age range 22e34 years old and BMI 22e25 kg/m2. Portions of tortillas containing 50 g of available carbohydrates were consumed by each volunteer over 10 min time period with 250 mL of water. Tortillas were ingested in random order on separate occasions in the morning after a 12 h overnight fast. Capillary finger-prick blood samples were taken from subjects at 0, 15, 30, 45, 60, 90, and 120 min after consuming the sample. Blood glucose concentrations were measured using OneTouch Ultra-Mini meter (Johnson & Johnson Miami FL, USA). Glycemic index was defined as the area under the blood glucose response curve for each tortilla treatment expressed as a percentage of the area after taking the same amount of carbohydrate as glucose. 2.11. Statistical analysis Comparison of means was performed by one-way analysis of variance followed by Duncan test analyzed by SAS software version 9.3 (SAS Institute Inc., Cary, NC).
Chemical composition of tortillas from the different nixtamalisation processes and treatments is reported in Table 1. There were no differences in the protein content of tortillas from the different nixtamalisation processes. Campechano et al. (2012) reported similar protein contents for TNP and ENP, ranging from 8.7 to 9.0%. Moisture content of fresh tortillas ranged from 46.3 to 51.8% with the highest value observed in ENP with CaCO3 and classic with saturated ash (data not shown). Overall, moisture content is similar with data reported by Campechano et al. (2012) and Pappa et al. (2010) for fresh tortillas elaborated with similar treatments. Differences in moisture content probably are related to water absorption during nixtamalisation and salts used. The fat content was significantly different between tortillas from the different nixtamalisation processes. Tortillas from ENP had higher fat values than tortillas made from CNP saturated ash. It is postulated that the alkaline pH in both the TPN and saturated ash CNP hydrolyzes the lipid ester linkages, and the free fatty acids are lost in the nejayote cooking liquor. The variation in tortilla fat among different nixtamalisation processes described here is similar to published values s et al. (2010). Campechano et al. (2012) also reby Maya-Corte ported a higher loss of lipids in the nejayote of the TNP compared to the ENP waste water. The ash content was higher in the CNP with saturated ash. However, there were important variations in crude fibre (Table 1). The EPN presented the highest crude fibre, explained by the retention of the pericarp and external layers of the maize grains during the different processing steps, which contain mainly fibre (cellulose, hemicelluloses). In the TNP, the pericarp and external layers are lost during the cooking, steeping and washing steps (Campechano et al., 2012). For this reason, the traditional tortillas and saturated wood ash CNP had lower values for crude fibre. Regarding dietary fibre there was a tendency to increase the total and insoluble fibre in EPN and CNP compared to TNP. The carbohydrate content in tortillas was within the values res et al. (2010). Values for ported for TNP and ENP by Maya-Corte total starch content ranged from 68.30 to 76.45%, and as expected lower values were found in tortillas from the ENP, as the higher concentration of crude fibre affected the total starch content (Table 1). The values for TNP tortillas are similar to the range re n-Villalobos et al. (2002). Total carbohydrate conported by Rendo tent of tortillas from CNP was similar to those reported by Pappa et al. (2010). In general, the total starch values in this study were within the rez et al., 2015) where range reported by several authors (Bello-Pe TNP and CNP saturated ash, had high total starch values. Differences in tortilla total starch can be explained by the loss of pericarp and other maize kernel outer layers in the cooking liquor during the nixtamalisation process that affected the percentage of total material recovered. 3.2. Minerals Tortillas are a good source of Ca, Fe, Mg and K, all of which are important micronutrients in the diet (Table 2). An important contribution from the nixtamalisation process is the significant increase in mineral content especially Ca and Fe, in maize products like tortillas compared to the mineral content of raw maize (Table 2). Figueroa et al. (2003) reported that tortillas provided 46% of the daily requirement of Ca when the tortilla consumption was about 325 g/day. A study comparing the properties of lime vs. wood ash processing found that the latter one provides 14.4 times the
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Table 1 Chemical composition of tortillas from different nixtamalisation processesa,b. Process
Protein (%)
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C₂H₅COO)₂ Classic 1% ash Classic saturated ash
8.69 8.61 8.30 8.08 8.21
± ± ± ± ±
0.6a 0.8a 0.1a 0.2a 0.4a
Fat (%) 3.15 3.77 4.23 3.41 2.26
± ± ± ± ±
Crude fibre (%)
Ash (%) 0.0b 0.03b 0.49a 0.51b 0.20c
1.30 1.36 1.36 1.27 2.76
± ± ± ± ±
0.04b 0.04b 0.08b 0.12b 0.08a
2.46 2.69 2.60 2.40 1.80
± ± ± ± ±
0.02c 0.02a 0.11b 0.01c 0.04d
IF (%) 9.83 10.86 12.28 13.40 13.23
SF (%) ± ± ± ± ±
0.29c 0.01b 0.02b 0.36a 0.51a
1.94 2.70 1.74 1.67 2.33
± ± ± ± ±
Carbohydratec (%)
TDF (%) 0.05c 0.28a 0.27c 0.12c 0.23b
11.78 13.60 14.01 15.08 15.56
± ± ± ± ±
0.34c 0.28b 0.25b 47a 0.28a
84.40 83.56 83.49 84.84 84.97
± ± ± ± ±
0.6 ab 0.34b 0.42b 0.45a 0.20a
Total starch (%) 74.85 68.30 72.30 73.40 76.45
± ± ± ± ±
0.21b 0.14e 0.14d 0.28c 0.21a
IF ¼ Insoluble fibre; SF ¼ soluble fibre; TDF ¼ total dietary fibre. a Means ± SD. Means with a different letter within the same column are statistically different (P < 0.05) (n ¼ 2). b Data reported on dry basis (w/w). c Carbohydrate content calculated by difference.
level of Fe, 15.0 times the level of Zn, twice as much Mg and 8.4 times K compared to the lime process (Pappa et al., 2010). A similar trend of the mineral content was observed in the present study (Table 2). In contrast, tortillas from TNP process had higher Ca content because calcium content in lime [Ca(OH)2] is two times higher than calcium salts and wood ashes (Table 2). For Fe, tortillas saturated with wood ash had the highest content; this mineral is one of the most limited micronutrients in the daily Mexican diet. Overall, Mg and K in tortillas decreased compared to raw maize. This could be explained in part by the loss of maize germ where K and Mg are found as salts of phytic acid (Bressani et al., 1990). 3.3. Thermal and rheological properties of native and annealed starch in nixtamal and tortilla samples from different nixtamalisation processes For the viscoamylographic RVA tortillas profiles, the CNP saturated wood ashes showed the highest peak viscosity value, this behavior suggests that with this process the starch granules have more interactions with maize chemical components, followed by TNP (Fig. 1). The present data agrees with others authors (Gujral et al., 2008) who indicated that in wheat the addition of ashes from incinerated wheat (1%e2%) increased the peak viscosity of the wheat flours. The same authors indicated that during the incineration process to obtain ash, the form of mineral constituents changed to oxides, sulfates, phosphates, chlorides, and carbonates. This result indicates that added ash may induce cross-links or ionic interactions among the flour components, mainly with the proteins, consequently increasing viscosity (Gujral et al., 2008; Santiago-Ramos et al., 2015b). Regarding functionality, little evidence is available concerning the effects of ash on flour. In baking and pasta applications, higher ash often plays a positive role. First, the extra minerals may result in a stronger dough and a finished product with more nutrition and better color. The present research also showed that the tortilla from ash presented mineral content important from the nutritional point of view (Table 2) but also good textural properties (data not shown). Santiago-Ramos et al. (2015b)
indicated that an increase in Ca(OH)2 concentration and consequently an increase of pH values of cooking solutions and nixtamal starch induced an increase of peak viscosity. The other two ENP variants and CNP with 1.0% of ash had a similar viscosity profiles. For tortillas samples peak viscosities were: 1193 cP for CNP saturaded wood ashes, 773 cP for TNP, 624 cP for ENP 1.0% carbonate and ENP with Ca-propionate 1.0% and 595 cP for CNP 1.0%. Those differences in viscosity indicate that pasting curves depends to the nixtamalisation process, and those parameters are affected by processing conditions. Final viscosity (FV) is related with cooling, this trend indicates that the elements present in the flour are associated during the retrogradation step and related to the flour quality during storage. CNP 1% and ENP with both salts had the lower FV it indicates a higher stability of starch to the cooking and cooling providing a softer tortillas for re-heating (Fig. 1).
Fig. 1. Typical RVA viscoeamylographic profile for tortillas prepared from different processes. A. Classic with 1% wood ash; B. Classic process with saturated wood ash; C. Ecological with calcium carbonate 1%.; D. Traditional with calcium hydroxide 1%; E. Ecological with calcium propionate 1%.
Table 2 Mineral composition of tortillas from different nixtamalisation processesa. Process
Calcium (mg/100 g)
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)₂ Classic 1% Ash Classic saturated Ash Wood ashes Lime [Ca(OH)2] Calcium propionate Calcium carbonate Raw maize
289.6 190.2 155.9 134.8 704.0 21,929 52,200 15,663 11,969 22.95
a
± ± ± ± ± ± ± ± ± ±
4.94a 2.75bc 1.76c 13.43e 86.26b 27.50 14.06 6.70 3.60 0.15
Iron (mg/100 g) 4.3 7.0 6.3 5.1 9.5 544.5 9.0 3.9 10.0 4.0
± ± ± ± ± ± ± ± ± ±
0.0e 0.01b 0.04c 0.04d 0.04a 8.40 0.52 0.37 0.07 0.12
Magnesium (mg/100 g)
Potasium (mg/100 g)
Zinc (mg/100 g)
138.3 ± 1.98b 146.3 ± 1.50c 148.4 ± 6.92d 149.8 ± 9.13a 196.0 ± 6.43e 907.70 ± 3.30 173.25 ± 0.98 __ __ 111.69 ± 0.12
263.7 ± 5.38c 275.4 ± 2.96b 281.8 ± 5.15d 256.2 ± 22.13e 310.2 ± 7.63a 2379.88 ± 15.2 310.1 ± 0.76 180 ± 1.47 __ 222.4 ± 0.63
3.1 3.4 4.6 3.7 4.0 2.5 5.35 22.5 2.0 2.15
Means (n ¼ 3) followed by a different letter within the same column are statistically different (P < 0.05). SD ¼ standard deviation.
± ± ± ± ± ± ± ± ± ±
0.35b 0.55b 0.50a 0.30 ab 0.28 ab 0.7 0.85 2.12 0.1 0.09
± ± ± ± ± 0.15 0.24 0.52 0.41 0.56 117.42 108.05 120.21 120.45 117.83 51.68 50.75 51.93 51.59 52.26 1.9a 2.03a 0.22a 0.81a 0.24a ± ± ± ± ± 44.47 42.90 44.75 43.67 45.02
To, Tp and Tf are onset; peak and final temperature, respectively. DH ¼ Enthalpy; DG ¼ Degree of gelatinisation; SD ¼ standard deviation. (I) Retrogradation (II) Amylose lipid complex. a Means ± SD followed by the same letter in the same column within the same product are not significantly different (P < 0.05).
109.50 105.70 105.07 103.26 103.55 92.55 98.77 85.98 91.43 86.61 e e e e e e e e e e e e e e e e e e e e e e e e e 0.88 1.24 0.63 0.48 0.39 59.79 60.33 60.34 60.50 61.21
e e e e e e e e e e
± ± ± ± ± e e
Maize Nixtamal Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C₂H₅COO)₂ Classic 1% ash Classic saturated ash Tortillas Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)2 Classic 1% ash Classic saturated ash
0.84a 0.49a 0.47a 0.24a 0.22a
e e e e e
± ± ± ± ±
0.54a 1.15a 1.35a 0.37a 0.69a
e e e e e
± ± ± ± ±
0.09 ab 0.18a 0.18bc 0.03bc 0.01c
63.735 66.53 64.52 68.44 66.18
± ± ± ± ±
0.23a 2.86 a 1.19a 0.33a 0.20a
70.55 72.47 73.10 75.25 73.85
± ± ± ± ±
0.23a 3.41a 0.21a 0.40a 0.37a
81.48 82.60 84.71 89.06 85.55
± ± ± ± ±
0.38c 1.29c 0.85b 0.33a 0.49b
4.11 6.26 3.36 6.63 4.12
± ± ± ± ±
0.40b 0.10a 0.18b 0.69a 0.53b
43.55 ± 0.06a 14.13 ± 0.01b 53.85 ± 0.02a 9.05 ± 0.01b 43.42 ± 0.07a
e e e e e
± ± ± ± ±
0.35b 0.12a 0.11e 0.15c 0.11d
e e e e e
± ± ± ± ±
0.03a 0.11b 0.09b 0.04b 2.04b
e e e e e
± ± ± ± ±
0.14 0.15 0.06 0.13 0.35
e e e e e
e e e e 0 7.29 ± 0.40 80.40 ± 0.14 70.37 ± 0.18 63.16 ± 0.33 e
To(G) ( C)
DH(I) (J/g) Tf(I) ( C) Tp(I) ( C)
Tortillas made with the TNP had 2.99% resistant starch content, n-Villalobos et al. a value consistent with reports from Rendo (2002) and Campas-Baypoli et al. (1999). There were no significant differences in RS between the nixtamalisation processes, except for saturated ash CNP, which showed lower value (Table 4). The amount of RS increased significantly when the maize was transformed into nixtamal and into tortillas, as result of the heat treatments that the grain is subjected to during the process steps. These treatments promote the interaction of the starch with other components (proteins, lipids or itself) making it less susceptible to enzyme hydrolysis (Saura-Calixto et al., 1993). Santiago-Ramos et al. (2015a) reported a range of 2.8e3.8% of resistant starch in tortillas obtained from ecologic however, those differences are in function of the different concentrations of calcium salts used.
To(I) ( C)
3.5. Resistant starch and glycemic index
Table 3 Thermal properties of nixtamal and tortillas from different nixtamalisation processes.a
Native maize showed an A type X-ray diffraction pattern, with peaks at approximately 15 , 17 and 23.4 (angle 2q), typical for cereal starches (Zobel, 1988). The A-type pattern is lost when maize is submitted to the nixtamalisation process and it is substituted by a V-type pattern denoting the formation of amylose-lipid complexes (Fig. 2). The latter one exhibits an additional peak at angle 2q ¼ 20 , which can be interpreted as a Vform due to the presence of these amylose-lipid complexes €ssler et al., 2006). After tortilla preparation and with the (Fa combination of water and temperature, amylose-lipid complex formation is stronger compared to the pattern of nixtamal. In Fig. 2, X-rays diffraction patterns for the five nixtamalisation processes evaluated in this study are shown. After nixtamalisation the maize lost part of the typical crystalline structure. The A-type was replaced by V-type in tortillas and nixtamal. The process that showed the highest degree of replacement was the saturated wood ash CNP.
Tp(G) ( C)
3.4. X-ray diffraction
e
Tf(G) ( C)
DH(G) (J/g)
DG (%)
To(II) ( C)
Tp(II) ( C)
Tf (II) ( C)
DH(G) (J/g)
Table 3 shows the thermal properties of maize, nixtamal and tortillas demonstrating significant differences in the majority of the parameters. The increase of onset, peak and final temperature of starch gelatinisation in all the nixtamalisation processes compared with native starch in maize is an evidence of starch annealing. These results are in agreement with previous reports that indicated the increase thermal properties was caused by starch modification in the nixtamalisation process (Campas n-Villalobos Baypoli et al., 1999; Figueroa et al., 2013; Rendo et al., 2002). The alteration within the starch crystallites of nixtamalised maize kernels might explain the increase in gelatinisation temperatures of annealed nixtamal starch samples compared to the native maize starch. In contrast, there was a reduction in entalphy from native maize to nixtamal, which can be attributed to starch gelatinisation. The enthalpy of native maize starch (7.290 J/g) was reduced between 3.365 and 6.630 J/g in annealed nixtamal. Gelatinisation was higher for ENP with Calcium propionate and CNP with saturated ash. Baks et al. (2007) mentioned that a typical gelatinisation endotherm of starch occurs in the thermogram between 51 and 76 C (Table 3). However, a shift of the gelatinisation endotherm of tortillas starch can be seen at lower temperatures compared to native starch. Table 3 shows that the transition endotherms in tortillas occur between 37 and 65 C. These values agree with the reports of García-Rosas et al. (2009) using TNP and SantiagoRamos et al. (2015a) with the TNP and ENP found the thermal transition in tortillas with temperature range of 23.4e64.0 C attributed it to the dissociation of retrograded amylopectin.
0.01d 0.04c 0.03a 0.02b 0.01a
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Fig. 2. X-ray diffraction patterns from the different nixtamalisation processes: A. Traditional with Ca(OH)2; B. Classic saturated wood ash, C. Ecological with 1% CaCO3, D. Ecological with 1% Ca(C2H5COO)2. Patterns are shifted along the linear intensity axis for clarity by adding constants of 1000 cps to each pattern except, for raw maize that maintains the original counts per second (cps) value.
Glycemic index for different products are shown in Table 4. Fifteen minutes after the tortillas were ingested, the lowest glucose values were seen for tortillas made with the 1% wood ash CNP, and the highest value for tortillas made from the saturated wood ash CNP. The GI was affected by the chemical composition of the tortillas and the amount of resistant starch present (Table 4). A low glycemic response is considered beneficial from a nutritional point of view, especially for individuals suffering from impaired glucose tolerance. Table 4 shows that the four non-traditional processes used in this study gave tortillas with a lower GI than traditional tortillas. According to the classification of GI by Foster et al. (2002), tortillas from the traditional process were found to be a food with intermediate GI. Consequently, tortillas made from the 1% calcium propionate ENP and the 1% wood ash CNP can be classified as low GI foods. These results are in agreement with those reported by Santiago-Ramos et al. (2015a) for traditional tortillas. 4. Conclusion
composition, influencing minerals, functional quality and nutritional properties. The nixtamalisation and salts used may inhibit the enzyme activity or increase the resistant starch content in the majority of tortillas. Tortillas made with ecological nixtamalisation process had lower Glycemic Index than tortillas made with traditional nixtamalisation process, however Classic nixtamalisation process with 1% ash had the lowest Glycemic Index and the highest iron content in tortillas. Tortillas elaborated with the Classic nixtamalisation process 1% ash and ENP with Ca propionate could be a healthier option for tortilla consumption, due to nutritional advantages. Acknowledgments Rosa María Mariscal-Moreno and David Santiago-Ramos thank the CONACYT for the Ph. D. scholarships. We thank Rosa María lez-Amaro from ECOSUR, Martín Adelaido Herna ndezGonza nica Flores-Casamayor from CinvestavLandaverde, and Vero taro for their technical support. Quere
Different nixtamalisation processes affected chemical tortilla References Table 4 Glycemic index for tortillas made from the different nixtamalisation processesa. Process for tortilla preparation
Resistant starch (%)
Glycemic Index
Traditional Ca(OH)2 Ecological CaCO3 Ecological Ca(C2H5COO)2 Classic 1% ash Classic saturated ash Glucose Maize
2.99 ± 0.11a 3.06 ± 0.19a 2.79 ± 0.12a 2.96 ± 0.11a 2.15 ± 0.09b e 0.86e0.93
70.0 ± 2.11b 60.0 ± 1.45d 37.4 ± 0.87e 29.2 ± 3.02f 69.6 ± 0.93 c 100.00a
a Means ±SD followed by the same letter in the same column are not significantly different (P < 0.05). SD ¼ standard deviation.
AACC International, 2000. Approved Methods of Analysis. Method 44 19.01 Moisture; Method 08e03.01 Ash; Method 46-16.01 Crude-Protein; Method 30-25.01 Fat; Method 32-10.01 Crude fiber; Method 32-40.01 Resistant Starch; Method 76-13.01 Total Starch; Method 40-75.01 Mineral content, eleventh ed. AACC International, St. Paul, MN. Asp, N.G., Van-Amelsvoort, J.M.M., Hautvast, J.G.A.J., 1996. Nutritional implications of resistant starch. Nutr. Res. Rev. 9, 1e31. Baks, T., Ngene, I.S., Van-Soest, J.J.G., Janssen, A.E.M., Boom, R.M., 2007. Comparison of methods to determine the degree of gelatinisation for both high and low starch concentrations. Carbohydr. Polym. 67, 481e490. rez, L.A., Flores-Silva, P.C., Agama-Acevedo, E., Figueroa-Ca rdenas, J.D., Bello-Pe pez-Valenzuela, J.A., Campanella, O.H., 2014. Effect of the nixtamalization Lo with calcium carbonate on the indigestible carbohydrate content and starch digestibility of corn tortilla. J. Cereal Sci. 60, 421e425.
146
R.M. Mariscal Moreno et al. / Journal of Cereal Science 65 (2015) 140e146
rez, L.A., Flores-Silva, P.C., Camelo-Me ndez, G.A., Paredes-Lo pez, O., Bello-Pe Figueroa, J.D.C., 2015. Effect of the nixtamalization process on the dietary fiber content, starch digestibility, and antioxidant capacity of blue maize tortilla. Cereal Chem. 92, 265e270. Bressani, R., Benavides, V., Acevedo, E., Ortiz, M.A., 1990. Changes in selected nutrient content and in protein quality of common and quality protein maize during tortilla preparation. Cereal Chem. 67, 515e518. nez, S.J.S., Campechano, C.E.M., Figueroa, J.D.C., Ar ambula, V.G., Martínez, F.H.E., Jime Luna, B.J.G., 2012. New ecological nixtamalisation process for tortilla production and its impact on the chemical properties of whole corn flour and wastewater effluents. Int. J. Food Sci. Technol. 47, 564e571. Campas-Baypoli, O.N., Rosas-Burgos, E.C., Torres-Ch avez, P.I., Ramirez-Wong, B., Serna-Saldívar, S.O., 1999. Physicochemical changes of starch during maize tortilla production. Starch/Starke 5, 173e177. €ssler, C., Arrigoni, E., Venema, K., Hafner, V., Brouns, F., Amado , R., 2006. DiFa gestibility of resistant starch containing preparations using two in vitro models. Eur. J. Nutr. 45, 445e453. Figueroa, J.D.C., Acero, M.G., Vasco, N.L., Lozano, A.G., Flores, L.M.A., 2003. Nutritional quality of nixtamal tortillas fortified with vitamins and soy proteins. Int. J. Food Sci. Nutr. 54, 189e200. gico de Figueroa, J.D.C., Rodríguez-Chong, A., Veles-Medina, J.J., 2011. Proceso ecolo n de harinas, masa y tortillas integrales. 15 de nixtamalizacion para la produccio agosto de 2011. Patente mexicana número 289339 (in Spanish). les, J.J.M., Herna ndez, L.M.A., Arago n, C.F., Gayta n, M.M., Figueroa, J.D.C., Ve Ch avez, M.E., Palacios, N., Willcox, M., 2013. Effect of annealing from traditional nixtamalisation process on the microstructural, thermal, and rheological properties of starch and quality of pozole. J. Cereal Sci. 58, 457e464. Foster, P.,R., Holt, S.H.A., Brand-Miller, J.C., 2002. International table of glycemic index and glycemic load values. Am. J. Clin. Nutr. 76, 5e56. rez, A., Yee-Madeira, H., Ramos, G., Flores-Morales, A., García-Rosas, M., Bello-Pe Mora-Escobedo, R., 2009. Resistant starch content and structural changes in maize (Zea mays) tortillas during storage. Starch/St€ arke 61, 414e421. mez, M.H., Lee, J.K., McDonough, C.M., Waniska, R.D., Rooney, L.W., 1992. Corn Go starch changes during tortilla and tortilla chip processing. Cereal Chem. 69, 275e279. lez-Amaro, R.M., Figueroa, J.D.C., Perales, H., Santiago-Ramos, D., 2015. Maize Gonza races on functional and nutritional quality of tejate:A maize-cacao beverage. LWT-Food Sci. Technol. 63, 1008e1015. Gujral, H.S., Park, S.J., Baik, B.-K., 2008. Effect of added minerals on pasting of partial waxy wheat flour and starch and on noodle making properties. Cereal Chem. 85, 97e101. Katz, S.H., Hediger, M.L., Valleroy, L.A., 1974. Traditional maize proccessing tecniques in the new world. Science 184, 765e773.
s, D.C., Figueroa-Ca rdenas, J.D., Garnica-Romo, M.G., CuevasMaya-Corte s-Martínez, R., Ve les-Medina, J.J., Martínez-Flores, H.E., Villanueva, R.A., Corte 2010. Whole-grain corn tortilla prepared using an ecological nixtamalisation process and its impact on the nutritional value. Int. J. Food Sci. Technol. 45, 23e28. ez-Gonza lez, D.E., Figueroa, J.D.C., Taba, S., Rinco n, F.S., 2006. Kernel microNarva structure of Latin American races of maize and their thermal and rheological properties. Cereal Chem. 83, 605e610. Pappa, M.R.P., Palacios, P., Bressani, R., 2010. Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics. Plant Foods Hum. Nutr. 65, 130e135. n-Villalobos, R., Bello-Pe rez, L.A., Osorio-Díaz, P., Tovar, J., Paredes-Lopez, O., Rendo 2002. Effect of storage time on in vitro digestibility and resistant starch content in nixtamal, masa and tortilla. Cereal Chem. 79, 340e344. n ~ez-Limo n, M., Alvarado-Gil, J.J., Vargas, H., Sa nchez-Sinencio, F., Rodríguez, M.E., Ya Figueroa, J.D.C., Martínez-Bustos, F., Martínez-Montes, J.L., Gonz alezHern andez, J., Silva, M.D., Miranda, L.C.M., 1996. Influence of the structural changes during alkaline cooking on the thermal, rheological, and dielectrical properties of corn tortillas. Cereal Chem. 73, 593e600. ndez, L.L.L., 2013. Nutraceutical Rodríguez, M.L.I., Figueroa, J.D.C., Ramos, M.G., Me properties of flour and tortillas made with an ecological nixtamalization process. J. Food Sci. 78, 1529e1534. Santiago-Ramos, D., Figueroa, J.D.C., Veles-Medina, J.J., Mariscal-Moreno, R.M., mez, M., Gayta n-Martínez, M., MoralesReynoso-Camacho, R., Ramos-Go nchez, E., 2015a. Resistant starch formation in tortillas from an ecological Sa nixtamalization process. Cereal Chem. 92, 185e192. Santiago-Ramos, D., Figueroa, J.D.C., Veles-Medina, J.J., Reynoso-Camacho, R., mez, M., Gayta n-Martínez, M., Morales-Sa nchez, E., 2015b. Effect of Ramos-Go annealing and concentration of calcium salts on thermal and rheological properties of maize starch during ecological nixtamalization process. Cereal Chem. 92. http://dx.doi.org/10.1094/CCHEM-12-14-0258-R. ~ i, I., Bravo, L., Man ~ as, E., 1993. Resistant starch in foods: Saura-Calixto, F., Gon modified method for dietary fiber residues. Food Sci. 58, 642e643. Shogren, R.L., Fanta, G.F., Felker, F.C., 2006. X-ray diffraction study of crystal transformations in spherulitic amylose/lipid complexes from jet-cooked starch. Carbohydr. Polym. 64, 444e451. Trejo-Gonz alez, A., Feria-Morales, A., Wild-Altamirano, C., 1982. The role of lime in the alkaline treatment of corn for tortilla production. In: Feeney, R.E., Whitaker, J.R. (Eds.), Modifications of Proteins: Food, Nutritional and Pharmacological Aspects. Advances in Chemistry. American Chemical Society, Washington, DC, pp. 245e263. Zobel, H.F., 1988. Starch crystal transformation and their industrial importance. €rke 40, 1e7. Starch/Sta