Legume Starches and Okra (Abelmoschus Esculentus) Gum Blends: Pasting, Thermal, and Viscous Properties

Food Sci. Technol. Res., 19 (3), 381–392, 2013

Legume Starches and Okra (Abelmoschus esculentus) Gum Blends:

Pasting, Thermal, and Viscous Properties

* Mohammed S. Alamri , Abdellatif A. Mohamed, Shahzad Hussain and Hassan A. Almania

Department of Food Science & Nutrition, King Saud University, Riyadh, Saudi Arabia, P.O. Box 2460, Riyadh 11451

Received November 26, 2012; Accepted February 25, 2013

The physical properties of chickpeas (CP) (Cicer arietinum var. surutato) and Turkish dry beans (TB) (Phaseolus vulgaris var. pinto) starches, as affected by Abelmoschus esculentus extract (OE), were examined. The properties were examined by rapid visco-analyzer (RVA), Brookfield viscometer, differential scanning calorimetry (DSC), and texture analyzer. The extract (OE) was added at 5, 10, and 15% of the starch to develop dry or wet blends. The RVA revealed that the peak and final viscosity as well as the setback of both starches were reduced in the presence of OE. The higher peak temperature (DSC) of the blends indicates slower starch gelatinization. Brookfield profiles demonstrated increase in shear stress at higher shear rate confirming pseudoplasticity of the system (n < 1). Arrhenius type model showed that starch blends viscosities exhibited higher activation energy indicating temperature dependency. Gener- ally, it can be concluded that OE has changed the properties of the starches, particularly, by decreasing viscosity, setback, and pseudoplasticity, gel hardness, and increasing syneresis of gels.

Keywords: okra gum, rheology, chickpea, beans, RVA, DSC, Brookfield, viscosity

Introduction suffer low stability and go down on viscosity against stress Starch granule-shape and degree of crystalinity varies and prolonged mixing (Temisiripong et al., 2005). Syneresis depending on its source. Amylose and amylopectin contents is the separation of water form starch gel and it occurs most- are the major determinants of the physicochemical properties ly during freeze-thaw of starch-containing frozen foods. of starch (Boudries et al., 2009). Amylopectin has a much Plant-derived non-starch polysaccharides (gums) such as higher molecule weight than amylose and it is branched at locust bean, guar, and flax seeds gums are excellent stabiliz- α-1-6- d-glucose unit. Amylose is linear chain of α-1- 4-d- ing and thickening agents used in many food systems. They glucose, in the most part, which is known to form a helix help to modify or control textural and rheological properties with different ligands, such as iodine and fatty acids. This and improve food stability (Hallagan et al., 1997; Chaisawa- characteristic is important because amylose-lipids complex ng and Suphantharika, 2005; Nagano et al., 2008). Several influences starch flow properties and its interaction with researchers reported that hydrocolloids such as flaxseed, other components in food systems. guar, xanthan, gellan, and carrageenan gums have significant Functionality of a particular starch paste is determined by effects on starch-pastes viscosity (Achayuthakan and Su- its water binding capacity, gelatinization temperature, paste phantharika, 2008; Rosell et al., 2011; Sae-kang and Suphan- clarity, solubility, swelling power, paste viscosity, retrogra- tharika, 2006; Nagano et al., 2008; Rodríguez-Hernández dation behavior and gel properties (Adebowale and Lawal, et al., 2006; Tischer et al., 2006). The viscosity of potato 2002). During processing/cooking of food, starch gelatini- starch is reduced by negatively charged hydrocolloids (cara- zation occurs due to heat and shear action. Upon cooling, geenans, CMC, xanthan gum), but increased by guar gum, starch paste retrograde which results in increase in paste vis- a neutral hydrocolloids (Shi and BeMiller, 2002). Natural cosity (Whistler and BeMiller, 1999). Native starches often gums or mucilages are sometime preferred due to their low cost, availability, and low reactivity (Baveja, 1988). *To whom correspondence should be addressed. Chickpeas (Cicer arietinum L.) originated in Turkey and E-mail: [email protected] have been produced in India and Middle Eastern countries. 382 M.S. Alamri et al.

The Kabuli type, which is called garbanzo bean, has a thin on top was removed and the white material at the bottom white seed coat with white flowers which is used mainly in of the bottle (the pellet) was re-suspended in distilled water salad bars or vegetable mixes and has larger seed than the and centrifuged at the same conditions mentioned above. desi type (Salunkhe et al., 1985). The Kabuli type chickpeas This process was repeated 5 times, after which, a white pure are of Mediterranean and Middle Eastern origin. Chickpeas starch fraction was obtained. The isolated starch was then contain 52.4 to 70.9% total carbohydrates, where starch is air-dried using acetone and ground in a coffee grinder, placed a major component of total carbohydrates (Salunkhe et al., in air-tight glass bottles, and stored at 4℃ for further use. 1985; Chavan et al., 1986) and constitutes 37.2 to 50.8% 2. Okra gum extraction Seedless okra (100 g) was of the whole seed and 55.3 to 58.1% of the dehulled seed. blended in 500 mL 0.05 M NaOH for 5 min in heavy duty There are many products require low amylose starch because blender. After centrifugation at × 2000 g, the supernatant of the retrogradation phenomena, such as frozen products, was collected and the extraction was repeated on precipitate. where freeze-saw cycles can damage the product’s texture. Supernatants were combined, pH was adjusted to 7, freeze Therefore, the amount of amylopectin is higher than amy- dried, ground and stored at 4℃ in air tight glass bottles for lose, where thermo-stable hot paste without breakdown and further use. This material will be called okra gum-extract restricted swelling is required making this starch useful for (OE) during the course of this work. The extracted okra gum special applications, e.g soups, porridges etc (Milao et al., was characterized in a previous publication by the same au- 2009; Polesi et al., 2011). Native chickpea starch contains an thors (Mohammed et al., 2013). average of 45.8% amylose, while Turkish beans starch aver- 3. Preparation of okra-starch blends Okra extract/ ages 52% amylose and the rest is amylopectin (Grelda et al., starch blends were prepared by replacing 5, 10 and 15% 1997). The gelatinization temperature of isolated legumes of each starch with okra gum powder (OE). Blending was starch (garbanzo beans, mung beans, red kidney, navy beans, done in two ways; mixing starch and okra gum powders in and fava beans) is 63.5 to 68℃ (Biliaderis et al., 1981). dry forms and labeled as dry mixed (DM). In the second Abelmoschus esculentus (L)Moench plant, commonly type, slurry (60% moisture content) of starch and OE was known as okra is rich in water extractable polysaccharides hand mixed in a test tube, vortexed, freeze dried, ground, that can develop high viscosity at very low concentrations and labeled as freeze dry mixed (FD). The reason for using (Onunkwo, 1996). Characterization of okra polysaccharide freeze-drying was to prevent starch gelatinization that may revealed that hot water or buffer extracted fractions were rich take place if heating method was used to dry the starch after in galactose, rhamnose and galacturonic acid (Sengkhamparn mixing. Additionally, mixing starch, gum, and water before et al., 2010). Due to their thickening properties, okra gum gelatinization was one of the points this work intended to polysaccharides are being used as fat and egg substitutes in discuss. The plain chickpea and Turkish beans starches (0% many dairy based products (Costantino and Romanchick- okra) were used as controls. Cerpoviez 2004; Romanchik-Cerpovicz et al., 2006). The 4. Rapid Visco Analyzer measurements (RVA) Pasting objectives of this work were to determine the effect of okra properties of both blends were determined using a Rapid Vis- gums (polysaccharides) on the functional and rheological co Analyzer (RVA) (Newport Scientific, Sydney, Australia). properties of chickpeas and Turkish beans starches. The wet Starch control or starch/okra blends (3 g at 14% moisture versus dry mixing of the blend will be investigated. basis) were directly weighed into aluminum RVA canisters and the total weight was brought to 28 g by adding distilled Materials and Methods water. The obtained slurry was held at 50℃ for 30 s, heated Materials Okra was purchased from a local supermar- to 95℃ in 4.40 min (at 10.23 ℃/ min) and held at 95℃ for ket. Okra pods were cut and seeds were removed before 4 min. It was then cooled to 50℃ in 2 min (at 22.5℃/min) extraction. Kabuli type Chickpea (CP) (Cicer arietinum and held at 50℃ for 2 min. The rotating speed of paddle var. surutato) and Turkish white dry beans (TB) (Phaseolus was 960 rpm for the first 10 s which was reduced and kept vulgaris var. pinto) starch was isolated from grains obtained at 160 rpm through the rest of the experiment. All measure- from local market. ments were done in triplicate and the Thermocline software Methods for Windows® version 3.11 (Newport Scientific Pvt. Ltd., 1. Starches isolation Slurry was prepared by mixing Warriewood, Australia) was used to process the data. chickpea (CP) or Turkish bean (TB) meal in distilled water 5. Syneresis studies on starch gels Gels obtained from (50/50) in heavy duty blender for 5 min. The slurry was RVA canisters were dispensed in graduated plastic centri- filtered through 200 mesh sieve. The filtrate was then centri- fuge-tubes and stored in a freezer at −20℃. After 4 day of fuged at × 2000 g for 15 min. After centrifugation, the layer storage, gels were placed in water bath at 50℃ for 30 min Legums Starch-gum Interaction 383 and centrifuged at × 3000 g for 15 min. The water separated 9. Gel texture Gel texture parameters were determined from gels, via centrifugation, was recorded and the gels were on RVA-prepared gels as described in section 5. with slight restored in freezer for another 4 days and water separation modification in method followed by (Lee and Yoo, 2011). after 8 day was recorded using same procedure. Percent The gels (35 mm in height) were transferred into 25 mL syneresis for the two freeze-thaw cycles was reported on 4th beakers having internal diameters of 30 mm and stored over- day, 4 days after that, and total after 8 days. night at room temperature. Gels were compressed using 6. Differential scanning calorimetry (DSC) The thermal Brookfield CT3 Texture Analyzer (Brookfield Engineering properties of the blend were determined using DSC analy- Laboratories, Inc. Middleboro, USA) in two penetration sis (Setaram instruments Micro DSC III Evo, SETARAM, cycles at a speed of 0.5 mm/sec to a distance of 10 mm us- France) using the method described by Mohammed et al. ing 12.7 mm wide and 35 mm high cylindrical probe. Gel (2012). hardness, springiness, cohesiveness and adhesiveness were 7. Rheological measurements Starch/okra cooked paste recorded. The gumminess was calculated as a product of obtained at 50℃ from RVA experiment (section 4) were used hardness and cohesiveness while chewiness as a product of for the determination of the viscosity and steady shear mea- gumminess and springiness. surements using a DV-III Brookfield rheometer (Brookfield 11. Statistical analysis All measurements were done in Engineering Laboratories, Inc. Middleboro, USA). So as to triplicate. One way analysis of variance technique was used maintain the temperature at 50℃, tests were done without to determine the effect of okra levels on chickpea (CP) and delay. In addition, since the samples will be transferred into Turkish beans (TB) starches including the two types of mix- a glass cylinder for rheological testing, the empty cylinder ing procedures. Duncan’s Multiple Range (DMR) test at p ≤ ® was kept in an oven at 50℃. Therefore, the temperature 0.05 was used to compare means using PASW (Chicago, IL, throughout the testing was maintained at 50℃. LV3 spindle USA) Statistics 18 software. with 0.7 cm diameter was used. The internal radius of the cylinder used for measurements was 1.15 cm. The calculat- Results and Discussion ed values of shear rate constant (SRC) and spindle multiplier Rapid Visco Analyzer (RVA) measurements Chickpea constant (SMC) were 0.33 and 128, respectively. Apparent starch (CP) exhibited 35 % higher peak viscosity (PV) com- viscosity was recorded at 25 different rpm’s starting upward pared to Turkish beans (TB) starch (Table 1) without influ- from 20 to 200 rpm with an increment of 15 rpm and down ence of mixing type. There was significant drop in PV of DM from 200 to 20 rpm with a decline of 15 rpm. The shear rate CP at higher OE, while the FD blend exhibited significant was ramped up and downward between 6.6 (20 rpm) and decrease at 15% OE. The final viscosity exhibited signifi- 66.6 s−1 (200 rpm). Data was recorded for apparent viscos- cant drop in the presence of OE for both starches including ity (mPa.s.) and shear stress (N.m2) for each freshly prepared FD and DM samples. It is well established in the literature sample. that, starch/water/ gum (OE) mixture is considered a biphasic 8. Temperature dependency (Arrhenius Equation) The system, where OE is located in the continuous phase and its temperature dependency was assessed by fitting the Ar- concentration increases as starch granules swell by absorbing rhenius equation model to the experimental data using water following heating (Achayuthakan and Suphantharika consistence index (n) as marker for the viscous character of 2008) which instigates higher viscosity of the system. The the starch paste. So that to bring the paste thickness down release of the absorbed water into the continuous phase fol- to a measureable range by Brookfield, the solid content of lowing granules rupture causes drop in the overall peak vis- these starch samples was scaled down to 1.5 g (14% basis) cosity (break down). Chaisawang and Suphantharika (2005) in a total of 28 g rather than the 3.0 g (14% basis) in 28 g and Gonera and Cornnillion (2002) proposed a different used for other tests. The slurry was placed in RVA canisters mechanism in regards to PV change at higher xanthan gum and tested using the same protocol described in section 4. compared to guar gum. The occurrence can be accredited Brookfield apparent viscosity and shear stress were recorded to xanthan gum capacity to completely cover starch gran- at 25 different rpm’s starting upward from 2 to 26 rpm at an ules and alleviate granules association, restrict swelling, and increment of 2 rpm and downward from 26 to 2 rpm at a dec- cause lower peak viscosity. The increase in PV of CP starch rement of 2 rpm. The shear rate was ramped up and down- + 5% OE blend could be due to adequate granules swelling ward between 0.66 s−1(2 rpm) and 8.58 s−1 (26 rpm). Data and OE ability to promote granule association which resulted was recorded at 50, 30 and 20℃ for apparent viscosity (mPa. in higher OE concentration located in the continuous phase, s) and shear stress (N.m2) at three replicates for each freshly whereas 10 and 15% OE lowered PV (Table 1). This can prepared sample. be interpreted by the limited granules swelling and associa- 384 M.S. Alamri et al.

Table 1. RVA peak and final viscosities of chickpea and dry beans (Turkish) starches as a function of okra extract content.

Chickpea Peak Viscosity (mPa.s.) Final Viscosity (mPa.s.) Set Back (mPa.s.) % OEa FDb DMc FD DM FD DM

0 2828 ± 91.92b 2828 ± 91.92a 4066 ± 194.45a 4066.5 ± 194.45a 2471 ± 106.77a 2471 ± 106.77a 5 3330 ± 60.81a 2572 ± 77.78b 3626 ± 66.47b 2989.5 ± 164.76b 1784 ± 152.74b 1198 ± 1.41b 10 2688 ± 32.53b 2221 ± 12.73c 2784 ± 21.92c 2354 ± 0.0c 1124 ± 103.24c 627 ± 29.70c 15 2146 ± 105.36c 1973 ± 19.80bd 2266 ± 128.69d 2080 ± 31.11c 608.5 ± 44.55d 470 ± 24.04c Turkish beans Peak Viscosity (mPa.s.) Final Viscosity (mPa.s.) Set Back (mPa.s.) % OE FD DM FD DM FD DM

0 1943 ± 43.13b 1943.5 ± 43.13a 3095 ± 67.18a 3095 ± 67.18a 1848 ± 145.66a 1848 ± 145.66a 5 2368 ± 232.64a 2215 ± 173.95a 2834 ± 241.83a 2570 ± 197.28b 840 ± 209.30b 627.5 ± 16.26b 10 2048 ± 79.20ab 1867 ± 115.97a 2351 ± 106.77b 2111 ± 56.57c 427.5 ± 27.58c 335 ± 4.24c 15 1887 ± 52.33b 1959.50 ± 142.13a 2129 ± 82.73b 2094 ± 166.88c 348.5 ± 21.92c 307.00 ± 52.33c

Means carrying same letters in columns are statistically non-significant aOE = okra extract; bFD = freeze-dried; cDM = dry mixed ; mPa.s.= millipascal Second tion theory, where OE covered starch granules and limited the pasting properties of the starch. The granule size of CP their swelling. It appears that the 10 and 15% OE provided and TB starches are 20 and 30µm, respectively, while the enough OE material to cover starch granules as contrasted amylose content for CP was reported around 47% and TB with the 5%. Unlike CP starch, the PV of TB starch was less 52.5% (Grelda et al., 1997). The amylose content is directly affected by OE higher than 5%. The comparison between related to granule structure and could influence its pasting FD and DM of CP samples reveled significantly lower PV as behavior, especially the final viscosity. a function of OE level (p ≤ 0.05) (Table 1). The final viscos- The setback values were significantly (p ≤ 0.05) lower at ity (FV) picture was different compared to PV, where signifi- all OE levels for the FD and DM for both starches (Table 1), cant drop in FV was noticed as a function of OE increase for but FD samples exhibited higher setback at each OE levels both starches and their blends. The viscosity data showed (statistics were not included), which points to premixing significantly higher PV and FV of FD CP starch compared of the blends that caused stronger network between starch to DM starch; while no significant difference was recorded components (amylose/amylopectin) and OE molecules. between FD and DM TB starch (statistics of this comparison Starch granules are affected by OE in two different ways, at was not included in Table 1). The PV of the FD samples the beginning of the starch gelatinization (OE covers starch could be due to more OE presence in the continuous phase of granules) and at the end where OE interacts with starch the blend which limits water mobility thus increases viscosi- components (amylose / amylopectin) after gelatinization. In ty. The different behavior of the two starches in the presence both situations OE had an effect on the peak viscosity and of OE can be attributed to starch granule structure as indicat- the setback of the starch. Therefore, the effect of premixing ed by higher peak viscosity of the pure CP compared to TB of starch and OE can be considered a significantly important starch. It is reasonable to state that, covering starch granules factor that affects starch pasting behavior. theory mentioned above does not apply when observing the The higher FV of starch gels as compared to PV is due to effect of higher OE levels on PV of TB starch, which could lower heat energy in the system caused by cooling as well as be attributed to the surface properties of TB starch granules amylose retrogradation. Although the final viscosity (FV) of such as the presence of proteins covalently bound to the the pure starch was higher than PV, the FV of either DM or surface of the granule. It is clear that the presence of higher FD blends was lower at higher OE content (Table 1). Since OE did not influence water absorption or granules associa- this is a replacement study, the drop in FV in the presence tion, but it did not allow increase in OE concentration in the of OE could be attributed to lesser amount of starch in the continuous phase rendering PV of TB unchanged. The same blend, which restrained starch retrogradation as shown by the trend continued for the FV of TB (Table 1). In addition, lower setback. granule size and amylose content could have direct effect on The setback data in Table 1 was further analyzed so as to Legums Starch-gum Interaction 385 determine the effect of OE on starch retrogradation and to culated and measured, respectively. The difference between establish whether the drop in setback is due to lower starch the theoretical and the RVA-measured was designated as the content or to some sort of actual OE functionality. In Table reduction in setback due to the presence of OE (Table 2). 2, setback data was presented as theoretical or actual (mea- Higher OE caused more setback reduction, but the drop in sured) values. For instance, the theoretical value for the 5% setback was not linear in the presence of OE. Arocas et al. OE blends was calculated based on subtracting 5% of the (2009) reported reduction in setback viscosity in the pres- measured setback value of pure starch since we have 5% ence of xanthan gum, which implies reduction in amylose less starch. This value was compared with the actual RVA- retrogradation, consequently, improvement in freeze-thaw measured value of the blends. So as to show the linearity of stability of starch gels. As reported by previous researchers, the drop in calculated setback shown in Table 2, chickpea positive correlations were observed between setback and fi- and Turkish beans control starches were tested by RVA simi- nal viscosity, but swelling power, amylose content, and peak lar to above. This time, the amount of starch used was 5, viscosity exhibited negative correlation (Singh et al., 2004). 10, and 15% less, i.e., for the 5% blend, the standard method The FD blends of both starches showed lower setback than call for 2.8 g of starch in a total of 28 g, but this time 2.66 g DM (Table 2), which is in line with other pasting properties was added in a total of 28 g (less solids). The same action presented and discussed above. In general, the overall effect was repeated for the 10 and 15% blends. The regression of FD on starch pasting properties can be attributed to better comparison between the calculated and measured setback spread of OE on the surface of starch granules, which facili- showed R2 values as follows; for chickpea starch 0.99 and tated for better interaction (contact). 0.98 for calculated versus measured setback, respectively, Freeze-thaw stability (syneresis) The syneresis of while Turkish beans starch exhibited 0.99 and 0.98 for cal- pure TB starch was higher than CP, which can be credited

Table 2. Calculated, RVA-measured starches setback, and the % setback reduction due to okra extract.

b c Calculated setback Measured setback Measured setback Difference d a % reduction % OE value due to starch value due to less starch value due to OE in setback due OE e in setback due OE replacement (mPa.s.) (mPa.s.) (mPa.s.) (mPa.s.) Chickpea Starch Setback Freeze dried (FD) 0 2471 2471 − − − 5 2347 1838 1748 599 26 10 2224 1298 1124 1100 49 15 2100 999 609 1491 71 Dry mixed (DM) 5 2347 1838 1198 1149 49 10 2224 1298 627 1597 72 15 2100 999 470 1630 78 Turkish bean Starch Setback Freeze dried (FD) 0 1848 1848 − − − 5 1756 1261 840 916 52 10 1663 793 427 1236 74 15 1571 480 349 1222 78 Dry mixed (DM) 5 1756 1261 628 1128 64 10 1663 793 335 1328 80 15 1571 480 307 1264 80

aOE=Okra extract bstarch dilution effect measured experimentally (cP) cdifference = calculated value – measured value. ddifference/calculated value ×100. emPa.s.= millipascal Second 386 M.S. Alamri et al. to higher amylose content of TB starch (52%) versus CP ties. The unnoticed changes could be attributed to the dry (47%). The higher amylose content squeezes the water out mixing process where the OE was located around the starch of the starch gel network attributable to retrogradation. Af- granules; unlike FD samples where the gum covered the ter the first freeze-thaw cycle (4 days), the syneresis of FD granules thus had more influence of the gelatinization prop- blends of both starches was significantly higher as a function erties of the starch. This effect was previously mentioned in of greater OE content (Table 3), despite the lower CP blend the course of discussing RVA pasting properties. A distinct syneresis compared to TB (p < 0.5). Higher OE content ap- endothermic transition was observed on the DSC profile pears to have no significant effect on TB starch syneresis (profile not shown), which represents starch gelatinization behavior (Table 3). Overall, FD samples exhibited signifi- curve at 62℃ for CP starch and 70℃ for TB starch (Table 4). cantly higher syneresis compared to DM (statistical analysis Indistinguishable peak was observed around 100℃, which results were not shown in Table 3). The second cycle (after can be attributed to amylose-lipids complex. The onset and 8 days total) was not significantly different for both starches peak temperatures of pure CP or TB starches were 56.1, at all OE levels aside from the DM of the CP. The syneresis 62.9℃; 57.7 and 70.5℃, respectively, whereas the pres- data was expected to show lower values than the pure starch, ence of OE has significantly increased the temperatures (p ≥ but it was higher as confirmed by the data (Charoenrein et 0.05) of both starches (Table 4). The area under the curves al., 2011). This data could mean that OE interacted with which represents the ΔH was 11.5 and 14.3 (J/g) for CP and amylose or controlled water mobility thus reduced setback TB starch, respectively. This data showed that TB starch has (lower retrogradation), but that was at 50℃. Therefore, OE more crystalline structure and more compact granules com- was not effective in preventing amylose retrogradation at pared to CP starch as indicated by the higher gelatinization freezing temperatures, causing syneresis of the blends to be temperature and higher ΔH (Table 4). Additionally, given higher than the control. It is likely that, OE molecules ag- that starch gelatinization is moisture-dependent process, gregated under freezing and became less effective which in samples were prepared at 60% moisture content, which al- turn caused amylose molecules to retrograde. It is apparent lows sufficient amount of water for starch gelatinization. A that there was no correlation between setback and syneresis clear increase in peak temperature as a function of OE con- action of OE. tent was observed (Table 4). This behavior can be related Differential scanning calorimetry (DSC) The DSC anal- to OE ability to limit starch water-absorption as was noticed ysis was done only on the FD samples because DM blends in the RVA peak viscosity discussed above. In conjunction showed no noticeable change in the starch thermal proper- with the delay in water absorption, the ΔH value was de-

Table 3. Effect of okra extract on the % syneresis for chickpea and dry beans (Turkish) starch gels freeze-dried and dry mixed blends as a function of higher Okra extract content.

Chickpea 1st 4 days 2nd 4 days Total %OEa FDb DMc FD DM FD DM 0 15.50 ± 0.73c 15.50 ± 0.73a 4.44 ± 0.09a 4.44 ± 0.09b 19.93 ± 0.64c 19.93 ± 0.64b 5 15.84 ± 1.16c 16.55 ± 1.77a 7.32 ± 0.48a 4.20 ± 1.30b 23.16 ± 1.64b 20.75 ± 0.47ab 10 20.03 ± 1.16b 8.71 ± 1.30b 6.97 ± 0.65a 12.06 ± 0.03a 27.00 ± 0.51a 20.77 ± 1.27ab 15 25.36 ± 1.00a 15.78 ± 2.22a 3.93 ± 2.24a 6.80 ± 3.15b 29.29 ± 1.24a 22.58 ± 0.93a Turkish bean 1st 4 days 2nd 4 days Total %OE FD DM FD DM FD DM 0 19.04 ± 1.15b 19.04 ± 1.15b 7.58 ± 3.22a 7.58 ± 3.22a 26.63 ± 2.07b 26.63 ± 2.07a 5 26.60 ± 1.45a 21.08 ± 1.26b 6.62 ± 2.62a 6.83 ± 3.19a 33.22 ± 1.17a 27.91 ± 4.66a 10 24.05 ± 1.52a 21.23 ± 2.41b 8.69 ± 0.42a 11.38 ± 1.84a 32.74 ± 1.95a 32.62 ± 4.25a 15 27.32 ± 2.55a 27.94 ± 1.60a 4.15 ± 0.64a 5.24 ± 0.76a 31.47 ± 1.91ab 33.18 ± 2.36a

Means carrying same letters in columns are statistically non-significant aOE=okra extract bFD=Freeze-dried blends; cDM=dry mixed blends Legums Starch-gum Interaction 387

Table 4. Effect of okra extract on the DSC profiles of chickpea and dry beans (Turkish) starches as a function of okra extracts content.

Chickpea starch + %OE a 0% 5% 10% 15% ∆H J/g 11.5 ± 0.35a 11.3 ± 0.09a 11.1 ± 0.00a 10.5 ± 0.64a b P T℃ 62.9 ± 0.14d 64.4 ± 0.08c 65.8 ± 0.13b 66.9 ± 0.18a c O T℃ 56.1 ± 0.57b 56.0 ± 0.18b 57.6 ± 0.08a 58.2 ± 0.13a Turkish bean starch + %OE a 0% 5% 10% 15% ∆H J/g 14.3 ± 0.08a 14.1 ± 0.10a 13.7 ± 0.18b 13.2 ± 0.06c b P T℃ 70.5 ± 0.42d 74.4 ± 0.14c 75.4 ± 0.02b 76.4 ± 0.08a c O T℃ 57.7 ± 1.80c 61.6 ± 0.71b 64.0 ± 51ab 65.3 ± 0.11a

Means carrying same letters in rows are statistically non-significant. a b c OE=Okra extract; Peak T℃; Onset T℃ creased as a function of higher OE. The drop in ΔH in the from Newtonian flow, which is n = 1. The n value for all presence of OE could be due to synergetic effect of the gum samples was n < 1 (Table 5) signifying that OE blends were on starch gelatinization mechanism i.e, faster gelatinization pseudoplastic material irrespective of the blends composi- rate and not only the initial steps. The behavior of CP starch tion, which is in agreement with previous reports (Mandala was different compared to TB, possibly due to the difference and Bayas, 2004). The data showed that, higher OE caused in amylose content and granule size (Table 4). Singh et al. the blend to become more pseudoplastic. The high coeffi- (2004) reported negative correlation between ΔH and setback cients of determination (R2) obtained confirm the power law and final viscosity of Indian rice cultivars as well as positive model to be amply appropriate for linking the flow properties correlation with peak viscosity. of OE-starch blends within the studied viscosity range. It is Rheological Measurements The rheological properties reported that pseudoplasticity of macromolecules solutions of starch pastes prepared in RVA were measured by Brook- is due to disentanglement of long chain molecules which field rotational viscometer at 50℃. Given that, non-standard causes reduction in intermolecular resistance to flow under Brookfield spindle (LV 3) was used, the spindle multiplier shear conditions (Nurul Azemi and Manan, 1999). Never- constant (SMC) and the shear rate constant (SRC), were theless, when sugar is added to macromolecules solutions calculated according to Alamri et al. (2013). Apparent vis- it suppresses disentanglement due to water molecules im- cosity measurements were carried out at 50℃ (Brookfield) mobilization; therefore it reduces pseudoplasticity (Chang to obtain shear rate versus shear stress data. The shear rate et al., 2004). Based on the mechanism of the effect of sugar (rpm) was set to increase from 20 to 200 rpm with 15 rpm on the flow properties of macromolecules and the increase in increment (ramping up) followed immediately by a reduction K value (equation 1) caused by sugar, it can be established (ramping down) from 200 to 20 rpm at the same rate. The that, the effect of OE on the mobility of water molecules rpm were converted to shear rate and the power law model was not observed due to the drop in K as a function of higher (equation 1) was fitted to the experimental data for ramping OE (Table 5). Wang et al. (2009) reported that addition of up and down. sugar moderately increased K value, but it was significantly boosted by a combination of sugar and xanthan gum. The Τ = Kγ· n (1) drop in K indicates that OE presence enhanced disentangle- Where T is shear stress (Pas), γ· is shear rate (s−1) converted ment of long starch chains causing lower resistance to shear from rpm, K is the consistency coefficient (Pas−1/n), and n is i.e., shear thinning (Table 5). This behavior was similarly flow behavior index (dimensionless). The K and n values evident in the drop of n (flow behavior index), which is the were obtained by taking the natural log of the shear stress reason for starch pseudoplastic nature (n < 1). Limited drop plotted against shear rate. The slope of the line as deter- in k value was noticed for the ramped down freeze-dried mined by linear regression was considered as n and the inter- blends of both starches (Table 5), which could mean that the cept as K (graphs were not shown). Linear regression results effect of OE on K was not concentration dependent. for ramping up and down are presented as K and n values Flow curves of shear stress versus shear rate were de- and shown in Table 5. termined at 50℃ at different shear rates (curves were not The flow behavior index, n, signifies sample deviation shown). The slope of the shear rate versus shear stress was 388 M.S. Alamri et al.

Table 5. The K =consistency coefficient (Pa.s) and the n = flow behavior index (dimensionless) of chickpea and dry beans (Turkish) starch pastes.

Chickpeas Ramping UP DM a FD b % OE c K d n e R2 % OE K n R2 0 5.17 0.12 0.85 0 5.17 0.12 0.85 5 4.19 0.39 0.99 5 4.49 0.28 0.88 10 3.59 0.58 0.97 10 4.03 0.42 0.97 15 3.81 0.36 0.97 15 3.37 0.45 0.97 Ramping Down 0 4.76 0.24 0.87 0 4.77 0.24 0.85 5 4.42 0.35 0.99 5 4.68 0.23 0.92 10 4.03 0.49 0.99 10 4.07 0.42 0.99 15 3.96 0.34 0.99 15 4.06 0.39 0.99 Turkish Beans Ramping UP DM FD % OE K n R2 % OE K n R2 0 4.19 0.40 0.99 0 4.19 0.40 0.99 5 3.35 0.50 0.99 5 4.39 0.23 0.99 10 3.43 0.41 0.99 10 3.82 0.33 0.99 15 3.78 0.29 0.99 15 3.73 0.34 0.99 Ramping Down 0 4.87 0.24 0.99 0 4.87 0.24 0.99 5 4.36 0.29 0.99 5 4.56 0.19 0.95 10 3.91 0.30 0.98 10 4.08 0.28 0.99 15 4.13 0.22 0.99 15 4.18 0.26 0.99

a DM = dry mix; b FD= freeze-dried; c OE = okra extract; d K =consistency coefficient (Pa.s.);e n = flow behavior index (dimensionless) calculated and used as indicator of OE influence on starch FD blends behaved alike. The slopes (obtained by linear re- gel flowing properties-change as a function of shear rate. gression) of ramped up FD CP starch blends were 0.12, 0.28, The curves showed no sign for counterclockwise shape at the 0.42, and 0.45 for the 0, 5, 10, and 15% OE respectively, beginning, which represents hysteresis loop (anti-thixotropic while the ramped down exhibited 0.23, 0.23, 0.42, and 0.39. behavior) in ramping up or down. Achayuthakan and Su- Therefore, based on these values, it appears that higher OE phantharika (2008) reported the presence of hysteresis loop content increased the slope value, thus have increased shear of waxy corn starch blended with guar gum at low shear stress change value within the same set of shear rate. The rates. The waxy corn starch systems are dominated with dry mixed CP exhibited similar trend. amylopectin molecules responsible for the thickening and Temperature dependency (Arrhenius Equation) Tables shear induced structure formation (Dintzis et al., 1996). The 6 and 7 show the effect of temperature on the rheological difference between the behavior of OE-starch blends, in properties of chickpea starch and OE-blends. A decrease in terms of hysteresis relative to reports in the literature were; the consistency coefficient (K) was observed at higher tem- previous researchers tested waxy starch at 25℃, while this peratures signifying a decrease in viscosity as a function of work tested common starches (47 − 52% amylose) at 50℃. temperature. The significant influence of temperature on the The TB control exhibited higher slope value, which could viscosity of bio-materials was reported by previous research- be interpreted as larger change in shear stress at higher shear ers (Sharoba et al., 2005; Ibarz et al., 1996). Koocheki et rate values as compared to CP. Overall, the curves of freeze- al. (2009) observed a decline in flow behavior index (n) dried (FD) and dry-mixed (DM) CP starch blends seem to with temperature of tomato ketchup, which indicates higher be influenced by OE content, where higher OE caused grater pseudoplasticity at higher temperature. Temperature has change in shear stress at higher shear rate. Evident differenc- limited influence on the apparent viscosity of considerably es between TB control and FD or DM blends were present in pseudoplastic products (Sharoba et al., 2005). Razavi et al. the course of ramping up or down, while the 10 and 15% OE (2007) reported a decrease in flow behavior index of starch- Legums Starch-gum Interaction 389

Table 6. Effect of okra extract levels and temperature on consistency coefficient (K) and flow behavior index (n) of freeze-dried chickpea and dry beans (Turkish) starch and blends measured at 20, 30, and 50℃. This Table was used for Arrhenius equation. Chickpea starch Temp. °C %OEa 0 5% 10% 15% n b K c R2 n K R2 n K R2 n K R2 Ramping up 20 0.18 2.66 0.87 0.11 2.23 0.87 0.18 1.94 0.98 0.19 1.99 0.98 30 0.12 2.58 0.96 0.29 1.64 0.99 0.24 1.66 0.99 0.24 1.74 0.99 50 0.26 1.79 0.99 0.39 0.84 0.98 0.49 0.87 0.99 0.49 0.96 0.99 Ramping down 20 0.28 2.45 0.95 0.28 1.86 0.98 0.34 1.57 0.99 0.24 1.86 0.99 30 0.29 2.19 0.99 0.53 1.05 0.99 0.42 1.28 0.99 0.32 1.56 0.99 50 0.43 1.42 0.99 0.94 0.23 0.98 0.63 0.59 0.99 0.50 0.87 0.99 Turkish beans Starch Ramping up 20 0.15 3.46 0.60 0.11 2.59 0.81 0.11 2.70 0.70 0.17 2.48 0.98 30 0.13 2.32 0.79 0.27 1.93 0.99 0.26 2.11 0.98 0.27 2.09 0.99 50 0.24 1.52 0.98 0.49 1.07 0.99 0.50 1.26 0.98 0.51 1.26 0.99 Ramping down 20 0.08 3.11 0.64 0.14 2.74 0.93 0.16 2.65 0.97 0.21 2.37 0.97 30 0.23 2.08 0.91 0.38 1.63 0.98 0.32 1.91 0.99 0.31 1.98 0.99 50 0.64 0.64 0.99 0.70 0.66 0.99 0.57 1.11 0.99 0.52 1.23 0.99

a OE=Okra extract; bn (dimensionless) and c K (Pa.s) indices are obtained by fitting the data to power law Τ = Kγ· n. This Table was used for Arrhenius equation. past/date syrup blends with temperature. Therefore, lower Table 7. Effect of different okra extract levels on Arrhenius-type n value indicates higher pseudoplasticity. The data in Table equation parameters of freeze-dried okra extract-chickpea and okra extract-dry beans (Turkish) starch and blends. 6 shows higher n at higher temperature, which means that in Chickpea starch the presence of OE, chickpea starch exhibited lower pseudo- % Oe a µ (Pasn)b Ea c R2 plasticity. This outcome, clearly indicate a less pseudoplastic o Ramping up material at higher temperatures, whereas a decrease in k was -2 2 0 3.25 × 10 10846 0.93 observed at higher temperature. The high R value con- -5 5 6.38 × 10 25535 0.99 firms the power law model to be a good fit to the data (Table 10 3.32 × 10-4 21264 0.99 -4 6). The behavior of chickpea starch and OE-blends during 15 8.00 × 10 19075 0.97 ramping up or down showed similar trend with respect to Ramping down the n and k. The temperature dependence of the viscosity 0 6.44 × 10-3 14566 0.93 5 3.08 × 10-1 55061 0.99 of chickpea starch and its blends was evaluated by fitting -5 10 3.38 × 10 26344 0.97 the data to Arrhenius type model; the confidence coefficient 15 5.19 × 10-4 20037 0.99 was plotted as a function of the selected temperatures (20, Turkish dry beans 2 30, 50℃). The high R is indicative of good relationship Ramping up between apparent viscosity and the temperature and obeys 0 6.29 × 10-4 20878 0.97 Arrhenius model (Table 6). Observed increase in the activa- 5 9.10 × 10-5 25190 0.99 -4 tion energy (Ea) of a bio-system signifies its temperature 10 8.01 × 10 19823 0.99 15 1.78 × 10-3 17715 0.99 dependency (Barbosa and Peleg, 1983). It can be seen in Ramping down Table 7 the increase in Ea of all blends relative to the con- 0 1.23 × 10-7 41693 0.99 trol, indicating more temperature dependency, whereas the 5 7.46 × 10-7 36828 0.99 Ea decreased with higher OE content. The lowest Ea value 10 2.61 × 10-4 19824 0.99 -3 among the blends was marked for the 15% OE, which is still 15 1.99 × 10 17301 0.99 a b n higher than the control. Therefore, the control showed the OE=Okra extract; μo (Pas ) = is the apparent viscosity at a reference temperature; c Ea = activation energy (J/ mol K-1) pa- lowest temperature dependence and the 5% OE registered rameters were obtained by fitting experimental data to Arrhenius the highest. The magnitude of hydrocolloids effect on the Ea equation (ln μa = ln μo + Ea/RT). 390 M.S. Alamri et al. of food systems is relative to hydrocolloid type and concen- drop in Ea value of the control at higher OE level except for tration. Additionally, Ea increases with soluble solid con- the 5% OE during ramping up (Table 7). The two starches tent increase in the system, such as sugar and other soluble exhibited different temperature dependency as indicated by molecules (Rani and Bains, 1987). Marcotte et al. (2001) the different Ea values recorded in Table 6 and 7, where CP reported lower activation energy for food systems containing starch appeared to be more temperature dependent compared xanthan gum, whereas Ea for starch and pectin-containing to TB starch. Additionally, if we consider higher Ea denotes systems was intermediate. The increase in Ea in the pres- high temperature dependency, higher Ea also means greater ence of OE can be attributed to its high solubility in water, influence of temperature on the viscosity. Therefore, TB vis- as indicated by its extraction method. The range of n for the cosity is more influenced by temperature because the Ea val- control starch was 0.18 to 0.26 and 0.15 to 0.24 for CP and ue, for both ramping up and down, was higher than CP starch TB, respectively. It is evident that CP starch is less pseudo- (Table 6 and 7). Similar difference between the two starches plastic than TB for ramping up and down due to the higher n was recorded in Table 1, where the final viscosity of TB was value (Table 6). The trend can be observed for all three OE lower than CP at the same holding temperature (50℃). levels and the three temperatures, whereas blends containing Gel texture After storage overnight at room tem- higher OE exhibited higher n value (less pseudoplastic). As perature, gels were tested mechanically for their hardness, it was the case for the CP starch, it is clear that OE causes cohesiveness, springiness, adhesiveness, gumminess, and drop in pseudoplasticity of TB starch due to its high water chewiness (Table 8). Turkish beans starch gel exhibited solubility (Table 6). The calculated Ea values for TB starch higher hardness than CP starch which is consistent with its are shown in Table 7. Unlike CP starch, the behavior of TB higher syneresis as well. Therefore, this could be attributed starch indicates less temperature dependency because of the to higher amylose content of TB starch (52%) versus CP

Table 8. Textural properties of starch gels stored overnight at room temperature. Chickpea starch + %OE a Freeze dried 0% 5% 10% 15% Hardness (N) 0.32 ± 0.01a 0.13 ± 0.01b 0.10 ± 0.00c 0.07 ± 0.00d Cohesiveness b 0.40 ± 0.04b 0.43 ± 0.01b 0.54 ± 0.01a 0.57 ± 0.01a Springiness (mm) 9.50 ± 0.28a 7.90 ± 0.14b 7.7 ± 0.14b 7.45 ± 0.21b Adhesiveness (mJ) 0.15 ± 0.07a 0.25 ± 0.07a 0.2 ± 0.00a 0.20 ± 0.00a Chewinessd (N.mm) 1.22 ± 0.01a 0.44 ± 0.00b 0.42 ± 0.00b 0.30 ± 0.00c Dry mixed Hardness (N) 0.32 ± 0.01a 0.19 ± 0.01b 0.15 ± 0.01c 0.14 ± 0.01c Cohesiveness 0.40 ± 0.04c 0.49 ± 0.02b 0.52 ± 0.00b 0.60 ± 0.01a Springiness (mm) 9.50 ± 0.28a 9.50 ± 0.28a 9.35 ± 0.35a 9.10 ± 0.14a Adhesiveness (mJ) 0.15 ± 0.07a 0.20 ± 0.00a 0.2 ± 0.00a 0.10 ± 0.00a Chewiness (N.mm) 1.22 ± 0.01a 0.88 ± 0.01b 0.73 ± 0.01b 0.76 ± 0.01b Turkish bean starch + %OE a Freeze dried 0% 5% 10% 15% Hardness (N) 0.41 ± 0.01a 0.26 ± 0.00b 0.22 ± 0.01c 0.11 ± 0.01d Cohesiveness 0.44 ± 0.01b 0.49 ± 0.04ab 0.44 ± 0.01b 0.55 ± 0.04a Springiness (mm) 8.55 ± 0.35a 8.90 ± 0.28a 9.00 ± 0.14a 8.65 ± 0.21a Adhesiveness (mJ) 0.10 ± 0.00a 0.10 ± 0.00a 0.20 ± 0.00a 0.30 ± 0.00a Chewiness (N.mm) 1.71 ± 0.01a 1.33 ± 0.00b 0.87 ± 0.01c 0.52 ± 0.01d Dry mixed Hardness (N) 0.41 ± 0.01a 0.27 ± 0.03b 0.21 ± 0.01c 0.15 ± 0.02d Cohesiveness 0.44 ± 0.01c 0.47 ± 0.01c 0.55 ± 0.02b 0.61 ± 0.02a Springiness (mm) 8.55 ± 0.35a 9.00 ± 0.42a 9.30 ± 0.00a 8.90 ± 0.14a Adhesiveness (mJ) 0.10 ± 0.00c 0.40 ± 0.00ab 0.50 ± 0.14a 0.25 ± 0.07bc Chewiness (N.mm) 1.71 ± 0.01a 1.14 ± 0.01b 1.07 ± 0.00bc 0.81 ± 0.01c a OE = Okra extract; gumminess = hardness × cohesiveness; bchewiness = gumminess × springiness; gumminess data was not shown in the table because it was used for calculating chewiness. Means in rows with the same letter are not significantly different. Legums Starch-gum Interaction 391

(47%), which forces water out of the gel as it retrogrades and References give rise to harder gel. Higher amylose content tends to cre- Achayuthakan, P. and Suphantharika, M. (2008). Pasting and rheo- ate stronger network caused by hydrogen bonding which can logical properties of waxy corn starch as affected by guar gum translate to higher retrogradation. As indicated by Liu and and xanthan gum. Carbohydr.Polym.,71, 9-17. Thompson (1998), and Yao and Ding (2002), starch retrogra- Adebowale, K.O. and Lawal, O.S. (2002). Effect of annealing and dation can be influenced by moisture distribution, which is heat moisture conditioning on the physicochemical characteristics possibly the case here in the presence of OE. Although TB of Bambarra groundnut (Voandzeia subterranea) starch. Food / gel was expected to have lower gel hardness due to its lower Nahrung, 46, 311-316. final viscosity and setback at 50℃ (Table 1and 2), the higher Arocas, A., Sanz, T. and Fiszman, S.M. (2009). Improving effect TB gel hardness can be attributed to the testing conditions, of xanthan and locust bean gums on the freeze-thaw stability of since gel-hardness was done at room temperature (about white sauces made with different native starches. Food Hydro- 25℃). Starches that exhibit harder gels tend to have higher coll., 23, 2478-2484. amylose content and longer amylopectin chains. Relatively Barbosa, C.G.V and Peleg, M. (1983). Flow parameters of selected high gel hardness of some starches could be desirable for commercial semi-liquid food products. J. Texture Studies., 14, specific food applications. Most of the tested parameters 213-234. decreased at higher OE content except for cohesiveness and Baveja, S.K., Ranga Rao, K.V. and Arora, J. (1988). Examination springiness (Table8). Gel hardness was significantly reduced of natural gums and mucilages as sustaining materials in tablets at higher OE (p ≤ 0.05). TB starch-gel displayed the high- dosage forms. Ind. J. Pharma. Sci., 50, 89-92. est value for hardness, and chewiness regardless of mixing Biliaderis, C.G., Grant, D.R. and Vose, J.R. (1981). Strructural method (FD or DM). Springiness of both starches, which characterization of legume starches. I.Studies on amylose, amylo- symbolizes recovery from deformation, was not influenced pectin and beta-limit dextrins. Cereal Chem., 58, 496-502. by the presence of OE at all levels except for FD CP starch Boudries, N., Belhaneche, N., Nadjemi, B., Deroanne, C., (Table 8). The amylose content of CP was 45.8% and TB Mathlouthi, M., Roger, B. and Sindi, M. (2009). Physicochemical was 52% which means that CP starch gel has weaker texture and functional properties of starches from sorghum cultivated in i.e., softer gel with more free water on surface and more the Sahara of Algeria. Carbohydr. Polym., 78, 475-480. sticky. In the presence of okra gum the springiness was sig- Chaisawang, M. and Suphantharika, M. (2005). Effects of guar gum nificantly lower compared to the control. and xanthan gum additions on physical and rheological properties of cationic tapioca starch. Carbohydr. Polym., 61, 288-295. Conclusion Chang, Y.H., Lim, S.T. and Yoo, B., (2004). Dynamic rheology of This work made clear that the thermal, pasting, and corn starch-sugar composites. J. Food Eng., 64, 521-527. rheological properties of chickpea and dry beans (Turkish) Charoenrein, S., Tatirat, O., Rengsutthi, K. and Thongngan, M. starches were largely affected by alkaline okra-gum extract, (2011). Effect of Konjac glactamnnan on syneresis and textural the extent of which depended on its concentration. The properties and microstructure of frozen rice starch. Carbohydr. peak, final, setback viscosities of starch were depressed at Poly., 83, 291-296. higher OE concentration. The freeze-dried and the dry- Chavan, J.K., Kadam S.S. and Salunkhe, D.K. (1986). Biotechnol- mixed blends exhibited different pasting behavior, which ogy and technology of chickpea (Cicer arietinum L.) seeds. CRC signify the importance of mixing. The drop in the setback Crit. Rev. Food Sci. Nutr., 25, 107-158. of FD chickpea starch was 26 to 71%, whereas the FD TB Costantino, A.J. and Romanchick-Cerpoviez, J.E. (2004). Physical starch exhibited increase in setback between 52 and 78% due and sensory measures indicate moderate fat replacement in frozen to OE, while DM showed values from 64 to 80%. Lower K dairy dessert is feasible using okra gum as a milk-fat ingredient values at higher OE indicates lower viscosity at higher OE substitute. J. Am. Diet. Assoc., 104, 44. and reaffirms the systems pseudoplasticity (n < 1). The in- Dintzis, F.R., Berhow, M.A., Bagley, E.B., Wu, Y.V. and Felker, F.C. crease in activation energy at higher OE content calculated (1996). Shear-thickening behavior and shear-induced structure in from Arrhenius type equation showed that the viscosity of gently solubilized starches. Cereal Chem., 73, 638-643. both starches was temperature dependent. Grelda, A., Yañez-Farias, J., Moreno-Valencia, G., Ma, R.F. and Je- sus, M.B. (1997). Isolation and partial characterization of starch Acknowledgements The Authors extend their appreciation to the from dry beans (Phaseolus vulgaris) and chickpeas (Cicer arieti- Deanship of Scientific Research at King Saud University for funding num). Starch/Starke, 49(9), 341-345. the work through the research group project No: (RGP-VPP-114) i. Gonera, A. and Cornillon, P. (2002). Gelatinization of starch/gum/ sugar systems studied by using DSC, NMR, and CSLM. Starch/ 392 M.S. Alamri et al.

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