Effects of cooking methods at different time durations on total phenolics and antioxidant activities of fresh and dried-stored fruits of Sonneratia apetala (Buch.-Ham.)

Cooking is the major method of consumption of the edible mangrove fruit of Sonneratia apetala (Buch.-Ham.). Effects of cooking methods-autoclaving, boiling, microwaving, pressure cooking and steaming on total polyphenol contents and antioxidant activities of both fresh and dried-stored seeds and pericarps of the fruits were studied. All the methods significantly (p < 0.01) enhanced total polyphenol contents, reducing power and total antioxidant capacity of both fresh and stored seeds on cooking for 20 min. Cooking for 20 min released two times higher amount of polyphenols from fresh seeds than from stored seeds. DPPH free radical scavenging activity of fresh seeds decreased at 2, 5 and 10 min cooking but increased the activity of stored seeds at 5, 10 and 20 min significantly. Cooking of both fresh and stored seeds significantly showed the higher contents of total polyphenol, DPPH scavenging, reducing power and total antioxidant capacity than pericarps did. In general, 20 min cooking is essential to obtain the highest amount of polyphenols and antioxidants from the fruit. No cooking method showed more significant advantages than the others. However, heat and pressure-tolerant polyphenols and antioxidants of S. apetala seeds might be used in food industries to produce functional foods and dietary supplements.