Paras Sharma

Phenolic Content and Antioxidant Activity of Germinated and Cooked Pulses

Five commonly consumed pulses, Mah (Vigna mungo), Green mung (Vigna radiata), Arhar (Cajanas cajan), Masur (Lens esculantus), and Moth (Vigna aconitifolia), were studied for their total phenolic content and antioxidant activity after germination (12 and 24 h) and pressure cooking. Arhar had the highest total phenolic content (6.71 mg ferulic acid/g flour) whereas Moth had the least (1.54 mg/g). All pulses, except Moth, showed a significant decrease in total phenolic content after germination. The antioxidant activity of the pulses varied from 10.61 to 36.38% (DPPH radical scavenging activity), which significantly decreased with germination in all pulses except Moth. The total phenolic content highly correlated with the antioxidant activity in the pulses. Cooking lowered the total phenolic content by 10–45% and antioxidant activity by 27–68% in the control and germinated pulses.

Total Phenolic Content and Antioxidant Activity of Extruded Brown Rice

Three paddy cultivars varying in l/b ratio (2.67–4.59) were dehusked to obtain brown rice. The brown rice was germinated for 24 and 48 h, dried, and milled into grit. The grit from controlled (un-germinated) and germinated brown rice was extruded at 100 and 120°C and the total phenolic content and antioxidant activity of the extrudates was determined. The total phenolic content of the control and germinated brown rice varied from 0.803–0.992 mg/g ferulic acid equivalent and germination increased total phenolic content by 8.8–12.0%. The antioxidant activity varied from 6.96–15.86% (decrease in absorbance of 2,2-diphenyl-1-picrylhydrazyl) and germination increased the antioxidant activity by 18.2–37.2%. Upon extrusion at 100°C, the total phenolic content decreased by over 50%. A further decrease of 6–15% in total phenolic content was observed when the extrusion temperature was increased from 100 to 120°C. Similar decrease in the antioxidant activity was observed upon extrusion and rise in extrusion temperature. Significant increase in water solubility, water absorption capacity, and percent expansion of extrudates was observed upon extrusion. The extrudates from germinated brown rice were used to make an instant pudding, which upon evaluation scored higher as compared to the pudding from control brown rice.

Anti-staling effects of β-glucan and barley flour in wheat flour chapatti.

Chapatti making behaviour of wheat flour containing barley flour (28%, 56% and 84%) or β-glucan (1.5%, 3.0% and 4.5%) and their effect on staling of chapatti was studied. The dough water absorption increased significantly up to 76.7% and 78.3% upon incorporation of barley flour and β-glucan, respectively. Bake loss significantly increased (up to 20%) upon incorporation of barley flour but was not significantly affected by β-glucan. The peak (PV) and final viscosity (FV) significantly increased upon incorporation of barley flour (up to 105% and 65%), whereas incorporating β-glucan decreased the PV and FV by 20.3% and 20.6%, respectively. The stored chapatties exhibited higher pasting viscosities compared to the fresh chapatties. Incorporation of barley flour exhibited a gradual increase in the enthalpy of gelatinisation (ΔHgel), similarly β-glucan at 1.5% increased the ΔHgel. Retrogradation was lowered by 23.7%, 41.5% and 63.5% by barley flour and by 19.9%, 27.4% and 44.8% by β-glucan.

Physiochemical, Pasting, and Thermal Properties of Starch Isolated from Different Barley Cultivars

Starches from eight different barley cultivars were isolated and evaluated for their physiochemical, thermal, and pasting properties. The amylose content varied significantly among cultivars and ranged from 21.0 to 28.3%. The majority of the starch granules were of the B-type (20 to 40 μm) in size and accounted for 50.5 to 61.6% of the total granules. The starch gel from RD-2052 showed the highest firmness (0.55 N). The pasting behavior of starch varied significantly; the PL-172 cultivar showed the highest peak viscosity (2622 cP) while it was lowest for RD-2035 (1913cP). The time to peak of pasting properties exhibited a significant (p ≤ 0.05) negative correlation with water solubility index (r = −0.74). The pasting temperature showed a significant (p ≤ 0.05) positive correlation with water binding capacity (r = 0.73) and significant negative correlation with water solubility index (r = −0.82). The highest enthalpy of gelatinization (ΔH) was exhibited by DWR-28 cultivar (4.9 J/g). Amylose content showed a significant (p ≤ 0.01) negative correlation with ΔH (r = −0.90). A significant (p ≤ 0.01) positive correlation was observed between gelatinization temperature range and water binding capacity of starch (r = 0.85).

Dough-Handling and Cookie-Making Properties of Wheat Flour–Watermelon Protein Isolate Blends

There is a growing interest in fortifying cereal-based products with proteins. In this study, protein isolates prepared from defatted seed meals of two watermelon cultivars, Mateera and Sugar baby, were blended with medium strength wheat flour at levels of 2.5% to 10%. Dough handling properties such as farinographic parameters, dough extensibility, pasting properties, textural and sensory properties of cookies revealed significant (p ≤ 0.05) changes in dough and cookies. Irrespective of watermelon cultivars, protein isolates at 5% and 10% levels, significantly (p ≤ 0.05) increased dough stability and mixing tolerance index while pasting properties decreased considerably with incorporation of 5% protein isolate in wheat flour. Similar changes were observed in textural, colour and sensory properties of cookies fortified with protein isolates. The protein content of cookies supplemented with protein isolates increased significantly (p ≤ 0.05) while a significant (p ≤ 0.05) decrease occurred in total carbohydrate content. Cookie fracture force (kg) significantly (p ≤ 0.05) increased above 5% fortification levels for both protein isolates. Cookie spread factor (W/T) increased with 2.5% to 7.5% fortification levels, but further increase in protein levels decreased spread factor. Sensory scores of cookies showed that protein isolates incorporation up to 7.5% were acceptable. This study revealed that watermelon protein isolates can be successfully incorporated in a range of cereal products to improve their protein quality and functionality.

Effects of incorporating germinated brown rice on the antioxidant properties of wheat flour chapatti

Brown rice after germinating for 24 and 48 h was milled into flour and incorporated in whole wheat flour at a level of 10% to prepare chapattis. The objective was to use chapatti as a delivery vehicle for germinated brown rice. The flour blends and chapattis made from the flour blends were evaluated for their antioxidant properties. Incorporating germinated brown rice flour increased the total phenolic content of the flour blend from 1897 to 2144 µg FAE/g. The total flavonoids content increased significantly from 632.3 to1770.9 µg CAE/g and metal chelating activity significantly increased by 71.62%. Antioxidant activity increased significantly by the addition of brown rice flour and addition of 24- and 48-h germinated brown rice flour further increased the antioxidant activity significantly. The total phenolic content and total flavonoids content decrease significantly in all the blends after baking the flour into chapatti. A decrease of 3% to 29% was observed in the total phenolic content and a decrease of 25% to 42% was observed in the total flavonoids content. However, baking of the flour blends into chapatti increased the reducing power, metal chelating activity by three folds and antioxidant activity from 64% to 104%.

Effect of incorporating hydrothermal, kilned and defatted oats on antioxidant and chapatti making properties of wheat flour.

Oats were subjected to treatments like defatting, hydrothermal cooking and kilning, milled into flour and then the control and treated flours were incorporated into wheat flour at 25% and 50% levels and chapatti making behaviour and antioxidant properties were studied. The treatments significantly affected the antioxidant properties of oats. Incorporating oat flours to wheat increased total phenolic content but lowered the antioxidant activity however both were decreased significantly upon baking. The reducing power of the oat blended flour was higher than the wheat flours and ranged from 8.0 to 15.5 μmol AAE/g and was further increased upon baking. The metal chelating activity of flour blends varied from 62.0% to 73.8% and further increased upon baking. After baking the total flavonoid content was lowered and ranged from 308 to 389 μg CE/g. The non-enzymatic browning index significantly increased up to 27.6% upon baking.

Antioxidant properties of legumes and their morphological fractions as affected by cooking

The antioxidant properties of 6 legumes: green gram (Vigna radiate), red kidney beans (Phaseolus vulgaris), chickpea (Cicer arietinum), red lentil (Lens esculenta), soybean (Glycine max), and moth beans (V. aconitifolia), and their morphological fractions were evaluated before and after cooking. Kidney beans had the highest total phenolic content (8.9 mg ferulic acid equivalents/g), DPPH free radical scavenging activity (38.1%), reducing power (85.5 μmol ascorbic acid equivalents/g), and total flavonoid content (0.9 mg catechin equivalents/g). Highest metal chelating activity was observed for moth beans (93.3%). The antioxidant properties of the seed coat in all the legumes were manifold higher as compared to the whole legume or its respective endosperm and removal of the seed coat significantly reduced the antioxidant activity. Although cooking brought about a reduction in the antioxidant activity of the legumes in majority of the legumes and their fractions, an increase in the metal chelating activity was observed.

Antioxidant Properties of Sand Roasted and Steam Cooked Bengal Gram (Cicer arietinum)

Nine different Bengal gram (Cicer arietinum) cultivars were subjected to sand roasting and steam cooking and the effect on antioxidant properties were evaluated. The control untreated Bengal gram cultivars varied significantly with respect to their antioxidant properties. Both the thermal treatments lead to a significant increase in total phenolic content of up to 54% upon roasting and 97% upon steam cooking, respectively. Similarly, a significant increase in antioxidant activity was also observed by roasting (up to 64.5%) and steam cooking (up to 225%). A significant decrease in total color difference was noticed upon roasting (up to 11%) and steam cooking (up to 21%). The reducing power was increased significantly after roasting and steam cooking, however, steam cooking brought about greater increase in reducing power (up to 109%). Metal chelating activity was increased by up to 91.5% upon roasting and steam cooking. The study revealed that the steam cooking brought about greater increase in total phenolic content, reducing power, and metal chelating activity as compared to roasting.