Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties

Accepted Manuscript Title: Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties Authors: Elnaz Salehi, Zahra Emam-Djomeh, Gholamreza Askari, Morteza Fathi PII: DOI: Reference:

S0144-8617(18)31368-7 https://doi.org/10.1016/j.carbpol.2018.11.035 CARP 14286

To appear in: Received date: Revised date: Accepted date:

30 August 2018 20 October 2018 11 November 2018

Please cite this article as: Salehi E, Emam-Djomeh Z, Askari G, Fathi M, Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties, Carbohydrate Polymers (2018), https://doi.org/10.1016/j.carbpol.2018.11.035 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. 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.

Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties

a

SC RI PT

Elnaz Salehia, Zahra Emam-Djomeha1, Gholamreza Askaria, Morteza Fathia

Transfer Research center for controlled release, Phenomena Laboratory (TPL), Department of Food Science,

Technology and Engineering, College of Agriculture and Natural resources, University of Tehran

1

U

Corresponding author : Zahra Emam-Djomeh [email protected]

M

A

OFIFG is a high molecular weight polysaccharide with an arabinoglucan structure The anti-DPPH radicals activity of the gum sample was comparable to that of BHT At low frequency, the OFIFG solution exhibited a concentrated behavior.

D

  

N

Highlights

TE

Abstract

A high molecular weight biopolymer was extracted from the fruits Opuntia ficus indica and

EP

characterized regarding physicochemical and rheological properties. Total carbohydrate, ash and

CC

moisture content of the polysaccharide extracted from the fruits of Opuntia ficus indica (OFIFG) were 88.85 ± 5.2%, 9.00 ±1.30%, and 7.65 ± 0.74%, respectively. OFIFG had glucose (78.0 %),

A

arabinose (12.9 %), xylose (4.8 %), galactose (2.4 %), and mannose (2.4 %), suggesting an arabinoglucan structure. Weight average molecular weight of OFIFG was to be 3.67×106 g/mol. The intrinsic viscosity of OFIFG was 0.37 dL/g in deionized water at 25 ºC. Steady shear measurement demonstrated that OFIFG is a shear thinning fluid. At low frequency, the gum

1

solution exhibited a concentrated behavior. The anti-DPPH radicals activity of the gum sample was comparable to that of BHT and more than the data cited for other natural polymers. It can be found that OFIFG can be used as thickener, stabilizer and antioxidant agent in food and

SC RI PT

pharmaceutical systems.

Keywords: Opuntia ficus indica; Chemical composition; Structural properties; Molecular

U

weight; Antioxidant capacity.

N

1. Introduction

A

Opuntia ficus indica is a plant extensively distributed in semi-dry countries such as Mexico,

M

Morocco, Tunisia, Eritrea, Ethiopia, Argentina, Peru, Bolivia, Brazil, the United States, Spain, Italy, Israel, Iran, and South Africa (Saénz, Tapia, Chávez & Robert, 2009). This plant belongs

D

to the Cactaceae family (Nharingo & Moyo, 2016). Opuntia ficus indica has a high ability to

TE

adapt to different environmental conditions, and therefore, can be planted in various ecological systems (Abdel-Hameed, Nagaty, Salman & Bazaid, 2014)]. Opuntia ficus indica is known with

EP

common names of chumbera in Spain, higo de las Indias in India, fico d’India in Italy, figue de

CC

Barbarie in France (Morocco, Tunisia, Eritrea, Ethiopia). In recent years, various parts of the plant such as root, stem, fruit, and flower have been used to

A

prepare beverage and dessert. For example, in Mexico, the fruits of this plant are eaten as fresh fruit (Sáenz, Sepúlveda & Matsuhiro, 2004) or canned. Furthermore, they also used to make the syrup, toffee (Sáenz, Berger, Rodríguez-Félix, Galleti, Corrales García & Sepúlveda, 2013). Gum extracted from different parts of Opuntia ficus indica is widely used for food applications. For example, it has been reported that the cactus mucilage is used to purify drinking water, and 2

also treat wastewater (Buttice, 2009; Mohamed, Saphira, Kutty, Mariam, Kassim & Hashim, 2014). The fruits of this plant have an extensive range of color (Sáenz, Berger, Rodríguez-Félix, Galleti,

SC RI PT

Corrales García & Sepúlveda, 2013). From a health point of view, a considerable amount of fibers with health effects such as weight control, blood cholesterol, and diabetes control have been detected in this plant (Uebelhack, Busch, Alt, Beah & Chong, 2014). Moreover, dietary

fiber present in the composition of opuntia clodade can reduce the risk of certain types of cancer, such as colon cancer (Lansky, Paavilainen, Pawlus & Newman, 2008).

U

Due to better functional properties and technological advantages of natural polymers than

N

synthetic ones, a growing interest is devoted to exploring new sources of hydrocolloid with

A

appropriate characteristics (Busch, Delgado, Santagapita, Wagner & Buera, 2018; Dokht,

M

Djomeh, Yarmand & Fathi, 2018; Hesarinejad, Razavi & Koocheki, 2015; Wang, Wang, Huang, Liu & Zhang, 2015). Thus, the present work was undertaken to characterize the chemical

D

composition, structural properties, rheological behavior and functional properties of the gum

EP

TE

extracted from the fruits of Opuntia ficus indica to predict its application in food industries.

CC

2. Materials and methods 2.1. Materials

A

Opuntia ficus indica fruit (OFIF) were purchased from a local market in Tehran. All the chemical used in this study were obtained from Sigma Aldrich Co.

2.1. Extraction 3

The extraction process was carried out by microwave assisted extraction as follows: 10 g OFIF was mixed with deionized water in a fruit: water ratio of 1:10 and then put into a PTFE extraction vessel. MAE was conducted using a microwave apparatus (CE2350F,

SC RI PT

Microwave Experiment Equipment, South Korea). Finally, the vessel was cooled at ambient temperature, filtered and freeze-dried.

2.2.Chemical composition

U

2.2.1. Proximate analysis

N

The yield of OFIF gum (OFIFG) was determined as the dry weight of the extracted gum relative

A

to the fruit weight. The amounts of moisture, fat, ash and protein in OFIFG composition were

M

quantified based on the standard methods of AOAC (International, 2005). In order to determine

D

the amount of carbohydrates in OFIFG; the phenol-sulfuric acid assay was used. D-galactose was

EP

TE

utilized as standard (Brummer & Cui, 2005).

CC

2.2.2. Elemental analysis The gum digestion using a mixture containing nitric acid and hydrogen peroxide with a ratio of

A

2:1 was conducted by a closed-vessel microwave system with a power of 400 W for 15 min. Then, the digested sample was cooled to 25 ºC and made up to 10 mL with deionized water. Elemental analysis of the prepared sample was done using an inductively coupled plasma optical emission spectroscopy (ICP-OES).

4

The details of the device operating conditions were as follow: RF generator power (W) = 1200, nebulization gas flow rate (L/min) = 0.1, auxiliary gas flow rate (L/min) = 0.2, plasma gas flow rate (L/min) =12, frequency of RF generator (MHz) = 40.68, sample uptake rate (mL/min) =1;

SC RI PT

Measurement replicates=3.

2.2.3. Monosaccharide determination

Monosaccharide constituent of OFIFG was measured by GC-MS analysis. Chromatographic

U

separation was performed by an Agilent gas chromatograph equipped with HP-5MS capillary

N

column under following conditions: The flow rate of helium as the carrier gas was kept at 1.2

A

mL/min. The chromatographic oven was programmed at 120 °C for 1 min, then increased to

M

300 °C at a constant rate of 6 °C/min-1, followed hold at 300 °C for 15 min.

D

For sample preparation, 1 g of the gum powder was admixed with 2 M trifluoroacetic acid (TFA)

TE

for 8 h at 100 °C and then subjected to microwave. Sodium borohydride was incorporated to the resulting reaction mixture to reduce the acid hydrolyzed polysaccharides (Wolfrom &

EP

Thompson, 1963). Finally, acetic anhydride and pyridine with a ratio of 10:1 were added and

CC

incubated at 100 °C for 20 min to acetylate the alditols.

A

2.3. Structural analysis 2.3.1. NMR analysis

5

1

H NMR spectrum was acquired to elucidate the structure of OFIFG. For this purpose, 5 mg of

OFIFG was dispersed in 0.5 mL D2O, and NMR spectrum was recorded on a 300 MHz Bruker

SC RI PT

model DRX Avance spectrometer. The measurement was conducted at 25 ºC.

2.3.2. FT-IR analysis

Fourier Transform Infrared (FTIR) spectrum of the gum sample was recorded on an FTIR

N

U

Spectrometer (PerkinElmer) in the wavenumbers of 400 to 4000 cm-1 at a resolution of 4 cm-1.

A

2.4. Antioxidant capacity

M

Total phenol content and anti-radical activity of gum solution against 2,2-diphenyl-1-

TE

D

picrylhydrazyl (DPPH) were determined to test its antioxidant capacity:

EP

2.4.1. Total phenol determination The phenolic compound of the gum was evaluated by the Folin Ciocalteau spectrophotometric

CC

assay (Singleton & Rossi, 1965) taking gallic acid as standard. 0.5 mL gum was mixed with 2.5 mL of 0.2 N Folin-Ciocalteau reagent and kept for 5 min, and 2.0 mL of 75 g/L Na2CO3 were

A

then incorporated and kept at 25 ᵒC for 1 h. At the final step, the absorbance of the resulting mixture was recorded at 760 nm with a UV/Visible spectrophotometer. Total phenol content of the sample was reported as mg gallic acid/100 g of the samples.

6

2.4.2. DPPH radical scavenging activity DPPH test was utilized to evaluate the antiradical activity of OFIFG according to the earlier reported assay (Blois, 1958) with slight modification. BHA was used as a reference standard. 0.5

SC RI PT

mL of methanolic DPPH solution (0.1 mM) was mixed with 3 mL of the tested gum solutions with various pre-determined concentrations, vigorously shook, and incubated for 30 min at 37 °C. Afterward, the absorbance of the solutions was read at 517 nm using a UV-VIS spectrophotometer (Shimadzu, Kyoto, Japan).

×100

(1)

N

AControl − 𝐴𝑆𝑎𝑚𝑝𝑙𝑒 𝐴𝑆𝑎𝑚𝑝𝑙𝑒

A

% inhibition =

U

The scavenging capacity of the samples was computed as follows:

TE

2.5. Rheological behavior

D

M

here, AControl and 𝐴𝑆𝑎𝑚𝑝𝑙𝑒 are the absorbance of the control and samples, respectively.

EP

2.5.1. Dilute solution behavior

The dilute solution properties of OFIFG solutions were analyzed by an Ubbelohde capillary

CC

viscometer (Cannon Instruments Co., USA). The device was immersed in a water bath to control temperature. The gum powders were readily dispersible. The stock solution was prepared by

A

dispersion of the pre-determined amount of gum in deionized water under constant mechanical stirring at ambient temperature (0.0017-0.020 g/mL). The prepared solutions were kept at refrigerator for overnight to be hydrated completely.

7

Firstly, the relative (ηrel) and specific (ηsp) viscosities were quantified, and then the intrinsic viscosity of OFIFG was determined using the following models:

𝜂𝑠𝑝 𝐶

= [𝜂] + 𝑘𝐻 [𝜂]2 𝐶

SC RI PT

Huggins equation (Huggins, 1942):

(2)

= [𝜂]+ 𝑘𝑘 [𝜂]2 𝐶

(3)

M

A

𝐶

N

ln 𝜂𝑟𝑒𝑙

U

Kraemer equation (Kraemer, 1938):

D

here, 𝑘𝐻 , 𝑘𝑘 , and C are the Huggins constant, Kraemer constant, and the polymer concentration,

TE

respectively.

EP

Tanglertpaibul & Rao model (Tanglertpaibul & Rao, 1987): 𝜂𝑟𝑒𝑙 = 1+ [η] C

CC

(4)

A

Higiro’s equations (Higiro, Herald & Alavi, 2006): 𝜂𝑟𝑒𝑙 = 𝑒 [𝜂]𝐶

(5)

8

1

𝜂𝑟𝑒𝑙 =1−[𝜂]𝐶

(6)

SC RI PT

2.5.2. Steady shear measurements The steady shear properties of OFIFG solutions with various concentrations were characterized by a rotational viscometer (DVR, USA) equipped with a heating circulator at 25 °C using an

SC4-18 spindle. The Power-law equation was employed to describe the steady shear behavior of

𝜏 = 𝑘𝑦 𝑛̇

A

N

(7)

U

the gum solutions:

M

where, 𝜏, 𝛾̇ , 𝑘 𝑎𝑛𝑑 n are the shear stress (Pa), shear rate (s-1), consistency coefficient (Pa sn) and flow behavior index (dimensionless), respectively.

D

In order to the preparation of the OFIFG solutions, the specific amount of gum powder was

TE

dispersed to deionized water on a magnetic stirrer at 25 ºC and then allowed to stand at the

EP

refrigerator for overnight to be hydrated completely.

CC

2.5.3. Dynamic rheological behavior

A

The dynamic rheological properties of the gum solutions were evaluated by a controlled-stress rheometer (Physica MCR 301, Anton Paar GmbH, Stuttgart, Germany) equipped with parallel plate geometry (50 mm diameter, and 1.000 mm gap). A P-PTD200/56 sensor was employed for the analysis. The values of storage modulus (G’) and loss modulus (G”) against strain at a frequency of 1 Hz were monitored to distinguish linear viscoelastic region (LVR), Frequency 9

sweep evaluation at LVR region was performed to analyze the viscoelastic behavior of the samples.

SC RI PT

2.6. Particle size measurements

To determine the surface-area-average diameter (d32) of the droplets of the emulsion, a particle

U

size analyzer was employed. The measurements were conducted in triplicates.

N

2.7. Molecular weight determination

A

Molecular weight properties (Mn and Mw) of OFIFG were estimated using gel permeation

M

chromatography (GPC) technique. The instrument was equiped with a PL Aquagel-OH MixedH column. For preparation f the sample, first, the gum powder was dispersed in deionized water,

TE

D

and de-dusted by passing through a 0.2 μm filter. Finally, the filtered solution was injected at a constant flow rate of 1 mL/min. Water was used as eluent and detection was conducted by a

EP

refractive index detector. A standard curve was plotted using dextran molecular weight

CC

standards (Mw between 5200 and 988000 g/mol). The measurement was performed at 25 ºC.

A

2.8. Statistics

All the analytical evaluations were performed in triplicate. The results of rheological properties were analyzed by one-way analysis of variance (ANOVA) using SPSS 16 (SPSS Inc., Chicago, IL). Duncan's multiple range test was utilized to compare the mean treatments.

10

3.

Results and discussions

3.1. Chemical composition Proximate analysis and monosaccharide constituent of OFIFG are summarized in Table 1. Total

SC RI PT

carbohydrate, ash and moisture content of OFIFG were 88.85 ± 5.2%, 9.00 ±1.30%, and 7.65 ± 0.74%, respectively. Furthermore, a trace amount of protein (0.86±0.03%) was also detected. Due to the sufficient hydrophobic, as bonding points and hydrophilic, as reducing surface tension, groups, the gums containing proteins are commonly used as a stabilizer (Segura-

U

Campos, Ciau-Solís, Rosado-Rubio, Chel-Guerrero & Betancur-Ancona, 2014). Furthermore, it

N

has been reported that carbohydrates can avoid the coalescence and flocculation of oil droplets

A

(Tomás, Bosquez-Molina, Stolik & Sánchez, 2005). Hence, it is expected that OFIFG can be

M

introduced as a stabilizer and emulsifier in food and other systems. Comparing the total carbohydrate content of OFIFG with commercial gums revealed that OFIFG has higher

D

carbohydrates than those registered for guar gum (71.1%) and gum ghatti (78.365), and near to

TE

that of locust bean gum (85.1-88.7%) (Busch, Kolender, Santagapita & Buera, 2015; Dakia, Blecker, Robert, Wathelet & Paquot, 2008; Kang, Cui, Chen, Phillips, Wu & Wang, 2011),

EP

which confirmed the purity of this gum.

CC

The monosaccharide composition of OFIFG measured by GC-MS is presented in Table 1. The results demonstrated that OFIFG is a complex polysaccharide containing glucose (78.0 %),

A

arabinose (12.9 %), xylose (4.8 %), galactose (2.4 %), and mannose (2.4 %). The small amount of xylose, mannose, and galactose in OFIFG structure exhibited a complex polysaccharide structure for this gum. It is observable that two monosaccharides of glucose and arabinose make

11

up about 91 % of total carbohydrate content, suggesting a backbone composed of arabinoglucan units. Based on most of the pharmacopeias, the moisture content of gums should be at about 15.0% due

SC RI PT

to its deterioration effect on quality and shelf-life of the gums (Malsawmtluangi et al., 2014). Ash content of PMG was 9.00 % which is greater than the data reported for locust bean gum

(0.7-1.5 %), lower than that of guar gum (11.9 %) (Cui & Mazza, 1996; Dakia, Blecker, Robert, Wathelet & Paquot, 2008). The elemental analysis of the sample was also performed to elucidate

U

its mineral profile. The results are shown in Table 1. It is evident that OFIFG has a considerable

N

amount of nutrient elements, and thus is a viable candidate for applying as a nutritional additive

TE

D

M

A

in the food formulations.

EP

Table 1

A

CC

Proximate analysis and monosaccharide composition of OFIFG* Composition (%) Carbohydrate Protein Ash Moisture Fat Monosaccharides Arabinose Galactose Xylose Mannose Glucose

OFIFG 88.85±5.2 0.86±0.03 9.00±1.3 7.65±0.74 MDL 12.19 2.40 4.80 2.40 78.00

Elements (ppm) Calcium (Ca) Magnesium (Mg)

14159.90 ± 248.90 2759.63 ± 61.71

12

Manganese (Mn) Potassium (K) Phosphorus (P) Copper (Cu) Aluminum (Al) Nickel (Ni) Sodium (Na) Arsenic (As)

8.51 ± 0.12 2161.02 ± 36.94 321.98 ± 2.13 177.53 ± 6.86 4004.94 ± 60.40 6.86 ± 0.02 2807.92 ± 91.14
CC

EP

TE

D

M

A

N

U

SC RI PT

Elements (ppm)

A

Fig. 1. GC-MS graph of OFIFG

13

3.2. Chemical structure Although various researches have been focused on the characterization of the gum obtained from different parts of O. ficus indica plant (Amin, Awad & El-Sayed, 1970; Majdoub, Roudesli,

SC RI PT

Picton, Le Cerf, Muller & Grisel, 2001; Matsuhiro, Lillo, Sáenz, Urzúa & Zárate, 2006; Paulsen & Lund, 1979), little is known about the structural characteristics of OFIFG. In the present work, the structure of OFIFG was elucidated by H1NMR and FT-IR analyses. The 1H NMR spectrum of OFIFG is depicted in Fig. 2, and the signals were assigned according to the literature (Cui, Eskin & Biliaderis, 1995; Sherahi, Fathi, Zhandari, Hashemi & Rashidi, 2017; Timilsena,

U

Adhikari, Kasapis & Adhikari, 2016). The diagnostic resonances at 1.07 and 1.16 ppm are

N

associated with the C-CH3 groups, and that observed is due to the presence of the COOCH3

A

group in OFIFG structure (Timilsena, Adhikari, Kasapis & Adhikari, 2016). The peaks at 4.46,

M

4.34, 4.07, 3.90 ppm are assigned to H5, H4, H3 and H2 of α-D-galactopyranuronic acid units connected 1→4, respectively (Grasdalen, Bakøy & Larsen, 1988; Vignon & Garcia-Jaldon,

D

1996). The peak observed at 4.10, 3.38 and 3.35 ppm arise from H2, H5, and H4 of

A

CC

EP

TE

rhamnopyranosyl residues, respectively (Matsuhiro, Lillo, Sáenz, Urzúa & Zárate, 2006).

14

SC RI PT U N A M

D

Fig. 2. 1H NMR spectrum of the OFIG

TE

The FTIR spectrum of OFIFG is presented in Fig 3. The FT-IR spectrum of the gum is similar to previously evaluated gums. The characteristics bands between 900 to 1200 cm-1 are known as

EP

polysaccharide's fingerprint region. In this region, the band at 893 cm-1 represents α and β

CC

linkages in the polymer structure (Percival & Percival, 1962). The wavenumbers around 1425 and 1621 cm-1 are related to symmetric stretching vibration of COO- present in the gum

A

structure. Due to the capability of calcium ion to interact with carboxyl groups present in the structure of OFIFG, It is expected that calcium ion can affect the thickening ability of this gum (Razavi, Cui, Guo & Ding, 2014).

15

The absorption at 2920 cm-1 is caused by the stretching vibration of C-H in a methylene group (CH2) and/or double overlapping with OH groups (Kacurakova, Capek, Sasinkova, Wellner & Ebringerova, 2000). The broad absorbance detected in wavenumbers of 3100 to 3500 cm-1 is

SC RI PT

arisen from the presence of hydroxyl groups. It has also been reported that this region is due to hydrogen bonding involving the hydroxyl groups of glucopyranose rings (Sharma & Mazumdar,

EP

TE

D

M

A

N

U

2013).

A

CC

Fig. 3. FT-IR spectrum of OFIFG

3.4. Molecular weight properties Macromolecular weight parameters of hydrocolloids including weight average molecular weight (Mw), number average molecular weight (Mn), the radius of gyration (Rg) and polydispersity index (PDI) profoundly affect the physicochemical and functional characteristics of polymers 16

(Yang, Jiang, Zhao, Shi & Wang, 2008). Here, the molecular properties of OFIFG were analyzed to explore its potential applications in food and other systems. The GPC profile of PFIFG is depicted in Fig. 3. Three small peaks and two large peaks are observable, demonstrating a low

SC RI PT

degree of homogeneity for this polysaccharide. The peaks corresponding to large peaks were utilized to estimate the molecular parameters of OFIFG. Accordingly, the value of Mw was found to be 3.67×106 g/mol, which is comparable to the data cited for guar gum (2.07 ×106

g/mol) (Busch, Kolender, Santagapita & Buera, 2015) and Descurainia Sophia seed gum (2.1

×106 g/mol) (Sherahi, Fathi, Zhandari, Hashemi & Rashidi, 2017) and greater than those of most

U

of hydrocolloids. As mentioned above, the molecular weight of polysaccharide has a notable

N

influence on their characteristics. For instance, the high molecular weight polysaccharide has

A

high inherent ability to reinforce the viscosity of foodstuffs (Faria et al., 2011). However, further

A

CC

EP

TE

D

conducted to confirm this result.

M

rheological analysis including dilute solution, steady state and viscoelastic analysis should be

17

SC RI PT U N A D

M

Fig. 3. GPC graph of OFIFG

TE

3.5. Antioxidant activity

EP

Polysaccharides are one of the most important antioxidants (Kardošová & Machová, 2006). These reports encourage us to analyze the antioxidant capacity of the gum extracted from

CC

Opuntia ficus indica fruit. DPPH radicals scavenging as well as total phenol content of OFIFG

A

were analyzed to estimate the ability of this gum to act as anti-oxidative agent. The DPPH radical scavenging activity is one of the most popular techniques for evaluating the antiradical activity of gums and mucilages (Abazović, Čomor, Dramićanin, Jovanović, Ahrenkiel & Nedeljković, 2006). The anti-DPPH radical ability of OFIFG with various concentrations in comparison to BHA, as the positive control, is depicted in Fig. 4. As it can be seen, the 18

antiradical activity of the sample is dependent on concentration. Following an increase in gum concentration from 50 to 400 μg/mL, the antiradical activity declined from 42 to 82%, exhibiting an electron-donating ability for OFIFG. The observed results are consistent with those of other

SC RI PT

previous researches (Malsawmtluangi et al., 2014; Pu et al., 2016). Polysaccharide interacts with free radical, and as a result, produces the products with high stability. The similar trend has been observed when the BHT concentration elevated. Surprisingly, the ability of OFIFG to inhibit

DPPH radicals was close to that found for BHT and more than the data cited for other natural polymers like Albizia stipulate and Prunus cerasoides gums (Malsawmtluangi et al., 2014;

CC

EP

TE

D

M

A

N

U

Thanzami et al., 2015).

A

Fig. 5. DPPH antiradical activity of various concentrations of OFIFG

Total phenol content of the sample was 45.23 ± 0.02 mg/g dry, as gallic acid, which is close to that of hsian-tsao leaf gum (43.47 mg/g dry, as gallic acid) (Lai, Chou & Chao, 2001). It has been reported that phenolic compounds impart antiradical activity to plant extracts (Bashi, Fazly Bazzaz, Sahebkar, Karimkhani & Ahmadi, 2012). As mentioned above, OFIFG has high phenol 19

content, and thus the antiradical activity of OFIFG arises from phenolic compounds. Further analysis should be conducted to characterize the phenolic profile of OFIFG. Overall, OFIFG can

SC RI PT

be introduced as a suitable substitute for BHA as synthetic antioxidants.

3.6. Rheological behavior 3.6.1. Dilute solution behavior

Various factors such as solvent quality, macromolecular structure, and molecular weight affect

U

the intrinsic viscosity of polymers. To detect the critical region, where the macromolecular

N

entanglements start, the plot of relative viscosity (ηrel) against polymer concentration was

A

depicted. According to the illustrated figure, the coil-overlap point for OFIFG was 0.37 g/dL. All

M

the experiments related to dilute solution properties were conducted below this point. Five most common equations were employed to estimate the intrinsic viscosity of the OFIFG solution. The

D

values of determination coefficient (R2), Adj-R2 and root mean square error were employed for

TE

the selection of the best model for describing the dilute solution behavior of the sample. The

EP

result indicated that Huggins model had the highest R2 and Adj-R2 and the lowest RMSE, demonstrating this model can be used to estimate the intrinsic viscosity of OFIFG. The intrinsic

CC

viscosity of OFIG was 1.57dL/g. Comparatively, the intrinsic viscosity of OFIFG was lower than the data cite for some commercial gums like Fenugreek (15.10 dL/g), Guar (15.80 dL/g), Tara

A

(14.55 dL/g) and Locust bean gum (14.20 dL/g). The quality of deionized water as a solvent for OFIFG was tested by Higgins constant (kHz). This parameter is commonly utilized to determine the solvent quality in dilute solution regime. Based on the literature, for a flexible molecule with an extended shape in the good solvent, this 20

parameter is in the range of 0.3-0.4. kHz. The value of kH for OFIFG was 0.35 (at 25 ºC), demonstrating that deionized water is a suitable solvent for OFIFG.

SC RI PT

3.6.2. Steady-state behavior

Fig. 7 exhibits the relationship between apparent viscosity and shear rate in the range of 1 to 100 s-1. As expected, with an increase of shear rate from 0 to 100 s-1, the magnitude of apparent

viscosity decreased. This effect is associated with the rearrangement of macromolecular chains

U

in the direction of flow which resulted in the reduction of the interaction between adjacent

N

polymer chains and improvement of apparent viscosity (Marcotte, Hoshahili & Ramaswamy,

A

2001). Furthermore, it has been attributed to the decrease in the number of chain entanglements

M

(Nehdi, 2011). As presented in Fig. 7-B, following an increase in OFIFG concentration, the apparent viscosity slightly increased which is related to the higher solid contents at higher

D

concentration. At higher gum concentration, increased macromolecular entanglements and

A

CC

EP

TE

interfacial film formation, in turn, increased the apparent viscosity (Maskan & Göǧüş, 2000).

21

SC RI PT U N A M D TE

CC

EP

Fig. 7. Viscosity-shear rate profile of OFIFG as a function of gum concentration.

3.6.3. Dynamic rheological behavior

A

In the present research, firstly, strain sweep test was conducted to determine the linear viscoelastic region (LVE) (data not shown). After determining LVE, frequency sweep evaluation was carried out to describe the oscillatory rheological behavior of OFIFG solution. Different types of rheological systems including dilute, concentrated and gels systems are recognizable by

22

frequency sweep test. Fig. 8 presents the frequency dependency of storage modulus (G') and loss modulus (G'') for OFIFG solution (2% w/w) is shown in Fig 8. It can be seen that in the range of frequency tested here, the magnitude of G’ and G” are frequency dependent, revealing the

SC RI PT

viscoelastic behavior of OFIFG. As it is observable in Fig. 8, at low frequency, the magnitude of G” was higher than G’,

reflecting concentrated solution behavior. But, at a higher frequency, the value of G' becomes

TE

D

M

A

N

U

higher than G", indicating a weak gel behavior.

EP

Fig. 8. Frequency sweep data of OFIFG solution at 25 ºC.

CC

2.3.3. Functional properties One of the most important functional properties of hydrocolloids is the control of emulsion shelf-

A

life (Dickinson, 2009). A convenient way to analyze the relative effectiveness of an emulsifier efficiency of the gums is the determination of emulsifier concentration needed to produce an emulsifying system with the minimum mean droplet size (Dickinson, 1988). The surface–volume mean diameter versus concentration of OFIFG is shown in Fig. 8. It can be seen that OFIFG can

23

serve as an emulsifier and stabilize oil in water emulsion. An excellent stabilizing property of polysaccharides is attributed to their high molecular weight and gelation ability (Koocheki,

M

A

N

U

SC RI PT

Taherian, Razavi & Bostan, 2009).

A

CC

EP

TE

D

Fig. 8. The surface–volume mean diameter versus concentration of OFIFG

24

4. Conclusion In the present work, we reported the physicochemical, structural and functional properties of a new source of hydrocolloid. OFIFG is a heterogenic polysaccharide composed of 88.85 ± 5.2%

SC RI PT

carbohydrate and 9.00 ±1.30% ash. The major monosaccharides present in OFIFG structure were glucose (78.0 %), arabinose (12.9 %), xylose (4.8 %), galactose (2.4 %), and mannose (2.4 %). Due to high molecular weight of 3.67×106 g/mol, it is expected that this gum can be used as a

good thickener and stabilizer. The apparent viscosity of OFIFG solutions were shear-dependent, indicating this gum can be employed in the formulations that need to high shearing such as

U

pumping. An excellent stabilizing property was observed for OFIFG which may be arise from its

N

high molecular weight and gelation ability. Thus, this gum can be as a stabilizing agent in drinks

A

and beverages. Furthermore, due to high viscofying ability of OFIFG, this gum can be

A

CC

EP

TE

D

M

incorporated into some dairy products such as yogurt.

25

Accepted Manuscript Title: Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties Authors: Elnaz Salehi, Zahra Emam-Djomeh, Gholamreza Askari, Morteza Fathi PII: DOI: Reference:

S0144-8617(18)31368-7 https://doi.org/10.1016/j.carbpol.2018.11.035 CARP 14286

To appear in: Received date: Revised date: Accepted date:

30 August 2018 20 October 2018 11 November 2018

Please cite this article as: Salehi E, Emam-Djomeh Z, Askari G, Fathi M, Opuntia ficus indica fruit gum: Extraction, characterization, antioxidant activity and functional properties, Carbohydrate Polymers (2018), https://doi.org/10.1016/j.carbpol.2018.11.035 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. 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.

Cui, W., Eskin, N., & Biliaderis, C. (1995). NMR characterization of a water-soluble 1, 4-linked β-d-glucan having ether groups from yellow mustard (Sinapis alba L.) mucilage. Carbohydrate Polymers, 27(2), 117-122.

International, 29(3), 397-402.

SC RI PT

Cui, W., & Mazza, G. (1996). Physicochemical characteristics of flaxseed gum. Food Research

Dakia, P. A., Blecker, C., Robert, C., Wathelet, B., & Paquot, M. (2008). Composition and

physicochemical properties of locust bean gum extracted from whole seeds by acid or water dehulling pre-treatment. Food Hydrocolloids, 22(5), 807-818.

N

evaluation/[edited by] JMV Blanshard, JR Mitchell.

U

Dickinson, E. (1988). structure and stability of emulsions. Food structure: its creation and

A

Dickinson, E. (2009). Hydrocolloids as emulsifiers and emulsion stabilizers. Food

M

Hydrocolloids, 23(6), 1473-1482.

Dokht, S. K., Djomeh, Z. E., Yarmand, M. S., & Fathi, M. (2018). Extraction, chemical

D

composition, rheological behavior, antioxidant activity and functional properties of Cordia myxa

TE

mucilage. International Journal of Biological Macromolecules.

EP

Faria, S., de Oliveira Petkowicz, C. L., de Morais, S. A. L., Terrones, M. G. H., de Resende, M. M., de França, F. P., & Cardoso, V. L. (2011). Characterization of xanthan gum produced from

CC

sugar cane broth. Carbohydrate Polymers, 86(2), 469-476. Grasdalen, H., Bakøy, O. E., & Larsen, B. (1988). Determination of the degree of esterification

A

and the distribution of methylated and free carboxyl groups in pectins by 1H-NMR spectroscopy. Carbohydrate Research, 184, 183-191.

27

Hesarinejad, M., Razavi, S. M., & Koocheki, A. (2015). Alyssum homolocarpum seed gum: Dilute solution and some physicochemical properties. International Journal of Biological Macromolecules, 81, 418-426.

SC RI PT

Higiro, J., Herald, T., & Alavi, S. (2006). Rheological study of xanthan and locust bean gum interaction in dilute solution. Food Research International, 39(2), 165-175.

International, A. (2005). Official methods of analysis of AOAC International. AOAC International.

Kacurakova, M., Capek, P., Sasinkova, V., Wellner, N., & Ebringerova, A. (2000). FT-IR study

U

of plant cell wall model compounds: pectic polysaccharides and hemicelluloses. Carbohydrate

N

Polymers, 43(2), 195-203.

A

Kang, J., Cui, S. W., Chen, J., Phillips, G. O., Wu, Y., & Wang, Q. (2011). New studies on gum

M

ghatti (Anogeissus latifolia) part I. Fractionation, chemical and physical characterization of the gum. Food Hydrocolloids, 25(8), 1984-1990.

TE

Fitoterapia, 77(5), 367-373.

D

Kardošová, A., & Machová, E. (2006). Antioxidant activity of medicinal plant polysaccharides.

EP

Koocheki, A., Taherian, A. R., Razavi, S. M., & Bostan, A. (2009). Response surface methodology for optimization of extraction yield, viscosity, hue and emulsion stability of

CC

mucilage extracted from Lepidium perfoliatum seeds. Food Hydrocolloids, 23(8), 2369-2379. Kraemer, E. O. (1938). Molecular weights of celluloses and cellulose derivates. Industrial &

A

Engineering Chemistry, 30(10), 1200-1203. Lai, L.-S., Chou, S.-T., & Chao, W.-W. (2001). Studies on the antioxidative activities of Hsiantsao (Mesona procumbens Hemsl) leaf gum. Journal of Agricultural and Food Chemistry, 49(2), 963-968.

28

Lansky, E. P., Paavilainen, H. M., Pawlus, A. D., & Newman, R. A. (2008). Ficus spp.(fig): Ethnobotany and potential as anticancer and anti-inflammatory agents. Journal of Ethnopharmacology, 119(2), 195-213.

SC RI PT

Majdoub, H., Roudesli, S., Picton, L., Le Cerf, D., Muller, G., & Grisel, M. (2001). Prickly pear nopals pectin from Opuntia ficus-indica physico-chemical study in dilute and semi-dilute solutions. Carbohydrate Polymers, 46(1), 69-79.

Malsawmtluangi, C., Thanzami, K., Lalhlenmawia, H., Selvan, V., Palanisamy, S., Kandasamy, R., & Pachuau, L. (2014). Physicochemical characteristics and antioxidant activity of Prunus

U

cerasoides D. Don gum exudates. International Journal of Biological Macromolecules, 69, 192-

N

199.

A

Marcotte, M., Hoshahili, A. R. T., & Ramaswamy, H. (2001). Rheological properties of selected

M

hydrocolloids as a function of concentration and temperature. Food Research International, 34(8), 695-703.

D

Maskan, M., & Göǧüş, F. (2000). Effect of sugar on the rheological properties of sunflower oil–

TE

water emulsions. Journal of Food Engineering, 43(3), 173-177.

EP

Matsuhiro, B., Lillo, L. E., Sáenz, C., Urzúa, C. C., & Zárate, O. (2006). Chemical characterization of the mucilage from fruits of Opuntia ficus indica. Carbohydrate Polymers,

CC

63(2), 263-267.

Mohamed, R., Saphira, R. M., Kutty, A. I., Mariam, N., Kassim, M., & Hashim, A. (2014).

A

Efficiency of using commercial and natural coagulants in treating car wash wastewater treatment. Australian Journal of Basic and Applied Sciences, 8(16), 227-234. Nehdi, I. (2011). Characteristics, chemical composition and utilisation of Albizia julibrissin seed oil. Industrial Crops and Products, 33(1), 30-34.

29

Nharingo, T., & Moyo, M. (2016). Application of Opuntia ficus-indica in bioremediation of wastewaters. A critical review. Journal of Environmental Management, 166, 55-72. Paulsen, B. S., & Lund, P. S. (1979). Water-soluble polysaccharides of Opuntia ficus-indica cv

SC RI PT

“Burbank's Spineless”. Phytochemistry, 18(4), 569-571. Percival, E. G. V., & Percival, E. (1962). Structural carbohydrate chemistry.

Pu, X., Ma, X., Liu, L., Ren, J., Li, H., Li, X., Yu, S., Zhang, W., & Fan, W. (2016). Structural

characterization and antioxidant activity in vitro of polysaccharides from angelica and astragalus. Carbohydrate Polymers, 137, 154-164.

U

Razavi, S. M. A., Cui, S. W., Guo, Q., & Ding, H. (2014). Some physicochemical properties of

N

sage (Salvia macrosiphon) seed gum. Food Hydrocolloids, 35, 453-462.

A

Sáenz, C., Berger, H., Rodríguez-Félix, A., Galleti, L., Corrales García, J., & Sepúlveda, E.

M

(2013). Agro-industrial utilization of cactus pear. Rome: Food and Agriculture Organization. Sáenz, C., Sepúlveda, E., & Matsuhiro, B. (2004). Opuntia spp mucilage's: a functional

D

component with industrial perspectives. Journal of Arid Environments, 57(3), 275-290.

TE

Saénz, C., Tapia, S., Chávez, J., & Robert, P. (2009). Microencapsulation by spray drying of

EP

bioactive compounds from cactus pear (Opuntia ficus-indica). Food Chemistry, 114(2), 616-622. Segura-Campos, M. R., Ciau-Solís, N., Rosado-Rubio, G., Chel-Guerrero, L., & Betancur-

CC

Ancona, D. (2014). Chemical and functional properties of chia seed (Salvia hispanica L.) gum. International Journal of Food Science, 2014.

A

Sharma, V. K., & Mazumdar, B. (2013). Feasibility and characterization of gummy exudate of Cochlospermum religiosum as pharmaceutical excipient. Industrial Crops and Products, 50, 776-786.

30

Sherahi, M. H., Fathi, M., Zhandari, F., Hashemi, S. M. B., & Rashidi, A. (2017). Structural characterization and physicochemical properties of Descurainia sophia seed gum. Food Hydrocolloids, 66, 82-89.

SC RI PT

Singleton, V., & Rossi, J. A. (1965). Colorimetry of total phenolics with phosphomolybdicphosphotungstic acid reagents. American journal of Enology and Viticulture, 16(3), 144-158.

Tanglertpaibul, T., & Rao, M. (1987). Intrinsic viscosity of tomato serum as affected by methods of determination and methods of processing concentrates. Journal of Food Science, 52(6), 16421645.

U

Thanzami, K., Malsawmtluangi, C., Lalhlenmawia, H., Seelan, T. V., Palanisamy, S.,

N

Kandasamy, R., & Pachuau, L. (2015). Characterization and in vitro antioxidant activity of

A

Albizia stipulata Boiv. gum exudates. International Journal of Bological Macromolecules, 80,

M

231-239.

Timilsena, Y. P., Adhikari, R., Kasapis, S., & Adhikari, B. (2016). Molecular and functional

D

characteristics of purified gum from Australian chia seeds. Carbohydrate Polymers, 136, 128-

TE

136.

EP

Tomás, S., Bosquez-Molina, E., Stolik, S., & Sánchez, F. (2005). Effects of mesquite gumcandelilla wax based edible coatings on the quality of guava fruit (Psidium guajava L.). Journal

CC

de Physique IV (Proceedings) (Vol. 125, pp. 889-892): EDP sciences. Uebelhack, R., Busch, R., Alt, F., Beah, Z.-M., & Chong, P.-W. (2014). Effects of cactus fiber

A

on the excretion of dietary fat in healthy subjects: a double blind, randomized, placebocontrolled, crossover clinical investigation. Current Therapeutic Research, 76, 39-44. Vignon, M. R., & Garcia-Jaldon, C. (1996). Structural features of the pectic polysaccharides isolated from retted hemp bast fibres. Carbohydrate Research, 296(1), 249-260.

31

Wang, F., Wang, W., Huang, Y., Liu, Z., & Zhang, J. (2015). Characterization of a novel polysaccharide purified from a herb of Cynomorium songaricum Rupr. Food Hydrocolloids, 47, 79-86.

SC RI PT

Yang, B., Jiang, Y., Zhao, M., Shi, J., & Wang, L. (2008). Effects of ultrasonic extraction on the physical and chemical properties of polysaccharides from longan fruit pericarp. Polymer

A

CC

EP

TE

D

M

A

N

U

Degradation and Stability, 93(1), 268-272.

32