Impact of Soaking and Germination Time on Nutritional Composition and Antioxidant Activity of Nigella Sativa

Indian traditional dishes make use of Nigella sativa seeds because of its distinctive aroma and taste but its application is restricted due to its pungent flavour which can be overcome by various methods of processing such as roasting, soaking, germination etc. Soaking and germination has a positive impact on the nutritional, sensorial and phytochemical attributes of Nigella sativa. The current study was carried out to standardize the optimum soaking and germination conditions with improved nutritional, sensorial and phytochemical attributes of seeds. Nigella sativa seeds were soaked for different time duration (0 hr, 6 hr, 12 hr and 18 hr) followed bygermination for0, 7, 9 and 11 days. The soaked and germinated samples were exposed to a temperature of 50ºC for drying till the constant moisture was obtained and analysed for various physiochemical, nutritional and sensory attributes. All the attributes under study were significantly affected by soaking and germination as compared to the control. Comparatively, except the moisture content all the phytochemicals and nutritional attributes decreased significantly from the control sample. Based on the qualitative attributes, soaking done for 18 hours along with 9th day of germination was observed to be the best and can be considered as the optimum condition to maintain the phytochemical to the safe level as well as reducing the antinutritional factors which can further be used for value addition.

Effect of processing on the antioxidant vitamins and antioxidant capacity of Vigna sinensis Var. Carilla

Cowpea (Vigna sinensis L. var. Carilla) flours obtained by fermentation with inoculum Lactobacillus plantarum (PF) or with the natural microorganisms present in the flour (NF) and subsequent heat treatment in an autoclave were prepared to study the effect of fermentation on the antioxidant vitamin content and on the antioxidant capacity. Bacterial counts and pH values, vitamins C and E, carotenoids, glutathione (GSH), superoxide dismutase-like activity (SOD-like activity), peroxyl radical-trapping capacity (PRTC), lipid peroxidation in unilamillar liposomes, and Trolox equivalent antioxidant capacity (TEAC) were evaluated in raw and processed cowpea flours. gamma-Tocopherol and delta-tocopherol were found in raw cowpea, whereas vitamin C and carotenoids were not detected. An increase in the vitamin E activity was observed in PF, whereas vitamin C and carotenoids were not detected in fermented cowpea flours. Fermentation or heat treatment in an autoclave after fermentation produced processed cowpea flours with lower PRTC, glutathione content, and SOD-like activity than those of the raw seeds. However, those processes increased the capacity to inhibit the lipid peroxidation in unilamellar lipoposomes and TEAC. According to the results obtained in this study, the fermentation of cowpeas (naturally or with L. plantarum) and fermentation and subsequent heat treatment in an autoclave are good processes to obtain functional cowpea flours having higher antioxidant capacity than the raw legume.