Effects of fermentation time on the bioactive constituents of Kinema, a traditional fermented food of Nepal.

Kinema is a traditional food prepared by the natural fermentation of cooked soybeans. The fermented Kinema is known to have several bioactive constituents, however, only limited reports on the effect of fermentation time on the bioactivity of Kinema are available. Therefore, in this work, changes in phenolics content and radical scavenging activity of Kinema at different fermentation times were explored. Furthermore, the optimum fermentation time for maximum bioactivities (total phenolic content, total flavonoid content, and DPPH radical scavenging activity) was determined using one-factor response surface methodology. The numerical optimization suggested an optimum fermentation time of 29.6 h with significantly higher total phenolics and flavonoid contents of 62.84 ± 0.89 mg GAEs/g dry extract, 45.41 ± 0.57 mg QEs/g dry extract, respectively (p < 0.05) compared to traditionally fermented Kinema. Similarly, the IC50 concentration for DPPH radical scavenging activity of 1.78 ± 0.01 mg dry extract/mL, was significantly lower than those for traditionally prepared Kinema (p < 0.05). Moreover, optimized Kinema had significantly higher overall sensory scores compared to the traditional sample. The results suggested that fermentation time affects the amount of bioactive constituents of Kinema. Further studies are needed to explore the changes in the type of phenolic and flavonoid compounds.

Phytochemicals, nutritional, antioxidant activity, and sensory analyses of Moringa oleifera Lam. collected from mid-hill region of Nepal.

This study was aimed to determine the phytochemicals and nutritional compositions, antioxidant activity and sensorial properties of Moringa oleifera extracts. The powders prepared from leaves and pods were mixed separately at the ratios of 1:0, 0:1, 0.25:0.75, 0.5:0.5 and 0.75:0.25 and labelled as mixtures A, B, C, D and E, respectively. Mixture A exhibited highest chlorophylls, tannins, phenolics and flavonoids contents (17.8 mg/g, 9.1 mg GAE/g, 91.1 mg GAE/g and 38.1 mg QE/g, respectively). The crude proteins content was higher (18.03%) in mixture A. The fats, fibres and carbohydrates amounts were higher (2.96%, 11.02% and 67.86%, respectively) in mixture B. The highest energy value (335.62 Kcal/100 g) and the highest antioxidant activity (83.2%) were in mixture A. However, most of the sensory attributes were ranked high for mixture D, signifying to use the equal proportion of leaves and pods powder of M. oleifera for the development of food products.