The present study was carried out to evaluate the total phenolic content and antioxidant properties of four selected underutilized fruits species: Manilkara hexandra (Roxb.) Dubard (Palu), Salacia chinensis L. (Himbutu), Schleichera oleosa (Lour.) Oken (Koan) and Eugenia uniflora (Cherry) grown in Sri Lanka. Antioxidative constituents were extracted into water and the antioxidant activity of fruit extracts was assessed using biochemical assays: 1,1-diphenyl-2(2,4,6-trinitrophenyl) hydrazine (DPPH) radical scavenging assay (n=3) and ferric reducing power assay (FRAP)(n=3). The total phenolic content was estimated using Folin-Ciocalteu's colorimetric assay and expressed as milligrams of gallic acid equivalents per 100 g of both fresh and dry weight of fruit. The fruit extracts tested exhibited a broad range of antioxidant activity as measured by DPPH radical scavenging and FRAP assays. The highest antioxidant activity was exhibited by Manilkara hexandra (Palu) in both assays performed. Furthermore, it was observed that the antioxidant activity as measured by the DPPH radical scavenging activity and FRAP assay strongly correlated (R 2 = 0.997) with total phenol content for extracts of all four underutilized fruit species tested. Therefore, the antioxidant activity of the fruits could be attributed to phenolic compounds present in the samples. This is the first time that antioxidant potential of some of the above fruits is reported.

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Lyophilized aqueous extracts of four underutilized fruit species namely Diospyros discolor (Velvet apple), Pouteria campechiana (Lavulu/Canistel), Phylanthus acidus (Mal-Nelli/Star gooseberry) and Phyllanthus emblica (Nelli/Indian gooseberry) were investigated for the antioxidant potential (AP) by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay and ferrous reducing antioxidant power (FRAP) assay. Total phenolic content (TPC) and total monomeric anthocyanin content (TMAC) were determined by Folin-Ciocalteu's colorimetric assay and pH differential method, respectively. Vitamin C (VitC) content of fresh fruit was evaluated titrimertically and expressed as mg of ascorbic acid in 100 g of fresh weight (FW). The TPC and TMAC were expressed as mg of gallic acid equivalents (GAE)/100g FW and mg of cyanodin-3-glucoside (C3G)/100g FW. The measured parameters differed significantly among four fruit species. The values ranged between 84. 42 -1939.70 mg GAE/100g FW, 10.41 -55.64 mg C3G/100g FW, 0.067 -310.63 mg FW/ml, 9 -81.29%, 238.25 -2891 Fe 2+ mol/100g FW and 17.12 -523.14 mg/100g FW for TPC, TMAC, IC50, RSA, FRAP and VitC, respectively. Phyllanthus emblica possessed highest values in all parameters while Phyllanthus acidus showed the lowest except in TPC. The lowest TPC was observed in Diospyros discolor. The extract of Pouteria campechiana also showed considerable amount of TPC (640 mg C3G/100g FW), RSA (76%) and VitC of 53 mg/ 100g. The results revealed that these underutilized fruit crops can be used as sources of natural antioxidants and vitamin C.

Fruits at 50% maturity stage were selected and six different treatments were applied to find the best storage conditions where, ambient temperature packed in transparent polythene (T1), stored in black polythene (T2), without packing (T3), refrigerator packed in transparent polythene (T4), refrigerator packed in black polythene (T5) and refrigerator without packing (T6).Physiological characters (weight, firmness, juice content and rotten %) and TSS, pH and Acidity of the initial and stored fruits were examined on every 7 th day for a period of 35 days. Sensory evaluation was conducted using 10 panelists to find out consumer preferences. During storage period minimum weight losses (from 85.1g to 73.1g), highest TSS (11.2), gradually decreasing of firmness, increase of pH ( from 2.6 ± 0.1) and reduction of acidity (from 1.6 ± 0.1 to 1.2 ± 0.06) were observed in fruits stored in refrigerator with packed of black polythene with glossy appearance yellow colour and 0% of rotten fruits. Sensory evaluation results of black colour polythene covered fruit stored in refrigerator had significantly higher (Pr>F 0.05) values such as 98% peel colour appearance, taste (88) and juice content (88). Therefore, stored in refrigerator packed in black polythene were the best quality fruits.