The Effect of Germinated Sorghum Extract on the Pasting Properties and Swelling Power of Different Annealed Starches.

Starches were extracted from chickpea (C.P.), corn (C.S.), Turkish bean (T.B.), sweet potato (S.P.S.), and wheat starches (W.S.). These starches exhibited different amylose contents. The extracted starches were annealed in excess water and in germinated sorghum extract (GSE) (1.0 g starch/9 mL water). The α-amylase concentration in the GSE was 5.0 mg/10 mL. Annealing was done at 40, 50, and 60 °C for 30 or 60 min. The pasting properties of annealed starches were studied using Rapid Visco-Analyzer (RVA), in addition to the swelling power. These starches exhibited diverse pasting properties as evidenced by increased peak viscosity with annealing, where native starches exhibited peak viscosity as: 2828, 2438, 1943, 2250, and 4601 cP for the C.P., C.S., T.B., W.S., and S.P.S., respectively, which increased to 3580, 2482, 2504, 2514, and 4787 cP, respectively. High amylose content did not play a major role on the pasting properties of the tested starches because sweet potato starch (S.P.S.) (22.4% amylose) exhibited the highest viscosity, whereas wheat starch (W.S.) (25% amylose) had the least. Therefore, the dual effects of granule structure and packing density, especially in the amorphous region, are determinant factors of the enzymatic digestion rate and product. Swelling power was found to be a valuable predictive tool of amylose content and pasting characteristics of the tested starches. The studied starches varied in their digestibility and displayed structural differences in the course of α-amylase digestion. Based on these findings, W.S. was designated the most susceptible among the starches and S.P.S. was the least. The most starch gel setback was observed for the legume starches, chickpeas, and Turkish beans (C.P. 2553 cP and T.B. 1172 cP). These results were discussed with regard to the underlying principles of swelling tests and pasting behavior of the tested starches. Therefore, GSE is an effortless economic technique that can be used for starch digestion (modification) at industrial scale.

Wheat-millet flour cookies: Physical, textural, sensory attributes and antioxidant potential.

Millet flour (water washed or alkali washed) was replaced with wheat flour (WF) at 0, 25, 50, 75, and 100% levels. Objectives of the research were to characterize the flour blends for their technical properties and to produce cookies with less or no gluten contents. All types of flour blends were evaluated for their pasting properties. The cookies were baked and evaluated for their textural and physical attributes. Inclusion of millet flour (both types) in wheat flour resulted in significant reduction in peak and final viscosities while setback viscosities were affected non-significantly. Pasting temperature was increased from 65 ℃ (100% wheat flour) to 91 ℃ (100% millet flour). The hardness of cookies was reduced in the presence of millet flour. Fracturability values of cookies with higher millet flour were higher as compared to control cookies (prepared from 100% wheat flour). Cookies prepared from blends having more that 50% millet flour were not much liked by sensory panelists. The phenolic contents of cookies containing higher levels of either water washed or alkali washed millet flour were found to be higher when compared to cookies prepared from plain WF (1.90 ± 0.14 mg gallic acid/g sample). The 2,2-diphenyl-1-picrylhydrazyl activity (%) of cookies ranged from 16.39 ± 0.34 (100% water washed millet flour) to 10.39 ± 0.26 (100% WF; control). The study will help the non-coeliac people to consume low gluten (≈1.6-6.5%) or gluten intolerant people to consume gluten-free cookies (0%) from millet flour having abundant of antioxidants and health-promoting polyphenols.

Dynamic rheological properties of corn starch-date syrup gels.

The rheological, pasting, and gel textural properties of corn starch blended with date syrup (DS) or sugar (SG) were studied. The average amylose content of the starch was 27.8%. Corn starch gel is considered elastic since the elastic modulus (G') was much greater than the viscous modulus (G″). Different effect between DS and SG on corn starch gel was observed, where SG addition and DS replacement experiments exhibited the highest G'. The tan δ of all samples was in the range of 0.02-0.20 indicating elastic behavior since it is less than unity. The hardness of starch gel ranged from 13 to 146 g and 212-145 for DS replacement and DS addition, respectively. Unlike the replacement experiment, the addition experiment exhibited significant increase in peak viscosity, setback and pasting temperature (p > 0.05). The magnitude of the effect of DS on corn starch gel was more evident compared to SG. This was apparent by looking at the slopes of the linear regression of the log of G' or G″ versus the log of frequency. Based on the information provided here, date syrup application can expand to cover the baking and beverage industries.