Effects of Processing Methods on Total Phenolic, Total Flavonoid and Antioxidant Capacities of Moringa Seeds

Abstract

This study evaluated the effects of fermentation time (48-120 h), roasting temperatures (120-150oC), cooking time (10-40 min) and germination time (2-5 days) on total phenolics, total flavonoids, reducing power and antioxidant potentials of moringa seeds. The results revealed that fermentation time significantly (p<0.05) decreased the total phenolic and antioxidant capacities with increasing fermentation time. However, there was significant (p<0.05) increase in total flavonoid where the values peaked at 96 h (7.20 mg/100 g) and 120 h (7.21 mg/100 g) fermentation time. Roasting temperatures had negetive impact where the total phenolic, total flavonoid, reducing power and antioxidant capacity significantly (p<0.05) reduced with increasing roasting temperatures. There were significant (p<0.05) and steady increases in total flavonoid, reducing power and antioxidant capacity with increasing cooking time. However, total phenolic exhibited significant reduction. Germination length exhibited increase in all the parameters measured. However, total phenolic and flavonoid contents peaked at the fourth day of germination 31.96 mg/100 g and 5.62 mg/100 g, respectively. The reducing power was highest at the second germination day (26.96 mmol/100 g) while antioxidant capacity was highest at the fifth day (39.42 mmol/100 g). Therefore, cooking and germiantion are most preferred in enhacing the bioactive compounds in moringa seeds.