ABSTRACT
Objective: To evaluate the free radical scavenging ability and antiradical activities of Ximenia caffra fruit extracts in their different ripening stages. Methods: Using standard procedures, Ximenia caffra fruit extracts were determined for ferrous ions chelating ability, nitric oxide and hydroxyl radical scavenging ability. Antiradical activities were assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) in which the fruit extracts were evaluated for the number of antiradical units (AU515), the number of antiradical units per 1 mg of extracts (EAU515) and the total number of antiradical units per 1g of raw fruits (TAU515). Results: The fruit extracts exhibited significant higher ferrous ion chelating and free radical scavenging capacity compared to synthetic antioxidants (standard). Fruit extracts in early ripening stage (ERS) exhibited stronger ion chelation, nitric oxide and hydroxyl radical scavenging ability with low effective fruit extract concentration required to reduce free radicals by 50% (EC50) that were 14, 25 and 30µg/ml respectively than the late ripening stage (LRS) extracts. The fruit extracts also showed high AU515, EAU515 and TAU515. The values of AU515 ranged from 0.93 to 0.95, while EAU515 from 78.30 to 79.34 and TAU515 ranged from 19762.46 to 23821.23 of the extracts in LRS and ERS respectively. Conclusion: Based on these observations Ximenia caffra is potentially beneficial to human health due to its strong ability to scavenge free radicals. Its utilization can potentially reduce the risk of degenerative diseases to human beings.
ABSTRACT
Aims: Emblica officinalis, locally known as Amla, is a highly nutritious seasonal fruit. The processed fruit could be an important dietary source of natural vitamin C with potent antioxidant activity. The aim of present investigation was to study factors influencing antioxidant potential of Amla and its products. Methodology: Three Indian varieties of Amla fruits in three ripening states (unripe, semi ripe and fully ripe) were analyzed for total phenolic contents, vitamin C as well as antioxidant potential. Two Amla products were studied over a period of 33 days for these parameters. Results: In the present data, the fully ripe stage of Amla had the highest value of vitamin C (804.4±0.8mg/100g) and polyphenols (1300.3±99.6mg/100g) than the unripe, semi ripe stages. The DPPH Scavenging activity was found to be highest in semi ripe stage. ABTS radical scavenging (IC50 values) of unripe, semi ripe and ripe were 18.5±0.0071, 34.7±0.026, 21.9±0.024 respectively. The stability study for syrup and pickle, processed from Amla fruit, demonstrated sharper decrease of the vitamin C content for pickle than decrease for syrup over the time 33 days but the polyphenols and the free radical scavenging activity remained the same over the time. Conclusion: The present study suggested that ripening stages influence the antioxidant potential of Amla fruit. The contents of vitamin C showed a significant decrease over time in syrup and pickle but the antioxidant potential remained unaffected.