The Change in Contents of Vitamin C, Total Phenolic, Total Flavonoid and Antioxidant Activities of Selected Fruits Stored under Refrigeration.

Abstract

Epidemiological studies pro\jde convincing evidence of the beneficial role of antioxidants present in fruits and vegetables for reducing the risk of non­communicable diseases. As many fruits are highly perishable, after harvesting, they are stored in cold conditions for many days before consumption. Therefore, understanding the changes in phytonutrient content during postharvest low­temperature storage is important for consumers, scientists and industrialists. This study aimed to evaluate the effect of cold storage, on contents of ascorbic acid (AA), total vitamin C (TVC), total phenolic (TPC), total flavonoid (TFC) and total antioxidant activities (TAA). AA was determined using AOAC method and TVC was determined using 2,4-DNP method. TPC and TFC were studied using Folin­Ciocalteu's reagent and AlCb colourimetric method respectively. TAAs were determined using DPPH and FRAP assays. Seven selected fruit cultivars grown in Sri Lanka namely, mango (Mangifera indica 'Seeni'), banana (Musa sp. 'Sour'), papaw (Carica papaya 'Red lady'), rose apple (Syzygium jambos 'Malaysian'), cashew apple (Anacardium occidentale), santol (Sandoricum koetjape), yellow sapote (Pouteria campechiana) have been used for the study. The fruits were freshly harvested and AA, TVC, TPC, TFC and TAA were determined just after harvesting, at their edible maturity.