Ritika B. Yadav

Characterization of banana, potato, and rice starch blends for their physicochemical and pasting properties

Abstract The properties of blends of banana, potato, and rice starches were studied to assess their suitability as an alternate for chemically modified starches. The blends of banana, potato, and rice starches were prepared in the respective ratio of 1:3:2, 3:2:1, and 2:1:3. The blend with higher proportion of banana and rice starches (BPR-213) showed highest water absorption capacity and oil absorption capacity. The blend with higher proportion of banana starch (BPR-321) showed highest swelling power at 95°C but lowest water solubility at 95°C among other starch blends. The blend made with higher amount of potato starch (BPR-132) had significantly higher paste clarity than other blends (p < 0.05). The potato starch had significantly higher least gelation concentration than all other starches and their blends (p < 0.05). The banana starch and blend with highest proportion of banana starch (BPR-321) showed significantly lesser percent syneresis and thus highest freeze–thaw stability. Potato starch as well as it blends with greater amount of potato starch (BPR-132) showed highest value for peak viscosity, hot paste viscosity, and final viscosity than other blends.

Electrophoretic Characterization and Functional Properties of Rice Proteins from Indian Rice Cultivars

Rice protein isolates and extracts of protein fractions were prepared from Indian rice cultivars, namely, Jaya, HKR-120, P-44, Sharbati, Bas-370, and HBC-19. The protein extracts were characterized using SDS-PAGE. The total protein contents of rice cultivars ranged from 5.46 to 7.02 g/100 g sample with albumin and glutelin fractions showing the highest variability among rice cultivars. The electrophoretic patterns of protein fractions exhibited many varietal differences with glutelin fraction revealing the most heterogeneous (10–17 polypeptide units) and prolamin fraction revealing the most homogenous polypeptide composition (3 polypeptide units). The alkali extracted rice endosperm protein isolates showed favorable emulsifying and foaming capacities particularly at an alkaline pH of 11. The total protein content was significantly correlated positive with foaming capacity (r = 0.917, p < 0.01) and negative with oil absorption capacity (r = −0.914, p < 0.05). The total protein content was also correlated significantly positive with cooking time (r = 0.956, p < 0.01) and cooked grain hardness (r = 0.966, p < 0.01).

Effect of incorporation of hydrocolloids on the physicochemical, pasting and rheological properties of colocasia starch

The effect of the addition of acacia gum and HPMC at the concentrations of 1.0, 1.5, and 2.0% on the physicochemical, pasting and rheological properties of colocasia starch was studied. The swelling power and solubility of colocasia starch increased significantly with increasing the concentration of both acacia gum and HPMC. The addition of acacia and HPMC to colocasia starch also influenced the pasting properties and showed a decrease in peak, breakdown, cold paste viscosity, and setback viscosity. This effect was more pronounced as the concentration of acacia or HPMC increased except HPMC at 2% concentration. The storage modulus (G′) was higher than the loss modulus (G″) and both increased with the increasing frequency. The magnitude of G′ and G″ decreased with the increase in gum (acacia and HPMC) concentration. The result indicated that the colocasia starch–HPMC paste exhibited slightly inferior viscoelastic properties as compared to colocasia starch–acacia paste.

Phenolic profile and antioxidant activity of thermally processed sponge gourd (Luffa cylindrica) as studied by using high performance thin layer chromatography (HPTLC)

ABSTRACT The effect of different extracting solvents (methanol, ethanol and butanol) and cooking treatments such as pressure cooking, microwave cooking and frying was studied in regards to phenolic profile and antioxidant activity of Sponge gourd (L. cylindrica). The antioxidant activity was investigated using different assays, namely, ferric thiocyanate test (FTC), thiobarbituric acid test (TBA), ferric reducing antioxidant power (FRAP) and DPPH free radicals scavenging test. A densitometric HPTLC analysis was performed for the analysis of phenolic acids and flavonoids. The inconsistent effect of cooking treatments on antioxidant potential was observed. In general, frying was most potent cooking treatments to retain the maximum antioxidant capacity. Correlation studies indicated that the phenolic compounds including flavonoids were mainly responsible for ferric reducing power, free radical scavenging activity and percent inhibition activity.

Physicochemical, pasting and rheological properties of colocasia starch as influenced by the addition of guar gum and xanthan gum

Starch–hydrocolloids blends have been used in foods to provide texture, moisture retention and desirable pasting and rheological properties. The study was aimed to assess the influence of addition of selected gum hydrocolloids like guar gum and xanthan gum at varied concentration of 1, 1.5 and 2% on the physicochemical, pasting and rheological properties of colocasia starch. The addition of gums significantly improved the water absorption, swelling power and solubility of colocasia starch. The results showed that the addition of gums increased the paste viscosities, storage and loss (G′ and G″) modulus and pseudoplastic behavior of the starch gels but reduced the retrogradation tendency of colocasia starch. Xanthan gum exerted a more pronounced effect in modifying the pasting and rheological properties of colocasia starch.

Quality characteristics of pearl millet malt as affected by steeping temperature and germination period

The effect of malting conditions on pearl millet malt quality was investigated. Grains were steeped for 24 h at different temperatures of 25, 30 and 35 °C and germinated at 25 °C for 24, 48 and 96 h. Generally, malt quality parameters such as malting loss, diastatic power, α- and β-amylase activity, free amino nitrogen (FAN), water extracts were significantly affected (P<0.05) by steeping temperature and germination time. Malting loss, FAN, hot water extract, diastatic power of the malt increased with increase in germination time as well as steeping temperature However germination time from 24 h onwards to 48 h exerted more pronounced enhancing effect on malting loss (140%), hot water extract (145%) and FAN (41%) of the malt. A steeping temperature of 30-35 °C and germination time of 4 days were found to be optimal for pearl millet malting as these conditions resulted in high diastatic power, α- and β-amylase activity, hot water extract, FAN and moderate malting loss.