Browsing by Author "Sarananda, K.H."

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    Ascorbic Acid and Antioxidant Level of Ceylon Olive (Elaeocarpus serratus) as Affected by Variety, Stage of Maturity at Harvest and Different Methods of Preservation
    (Uva Wellassa University of Sri Lanka, 2010) Rasanayaka, R.M.D.D.M.; Sarananda, K.H.; Ranawana, S.R.W.M.C.J.K.
    There has been growing interest in the beneficial health effects of edible fruits as well as certain beverages. Their protective mechanisms against chronic-degenerative diseases are thought to be attributed to the presence of natural antioxidants, minerals and vitamins. In this study attempts were made to investigate. the dynamics of changes in ascorbic acid, antioxidant activity, pH, titratable acidity and Total Soluble Solids (TSS) in two varieties of Ceylon Olive (Elaeocarpus serratus); Pol weralu and Heen weralu and to evaluate the quality of Ready to Serve (RTS) drinks prepared from both varieties. Ready to serve drinks made of olive have evaluated for sensory attributes. The level of ascorbic acid was measured using 2, 6-Dichlorophenol-Indopenol (DCPIP) method. Methanolic extracts of fruits and RTS drinks were analyzed by DPPH (1, 1-dipheny1-2- picrylhydrazyl) antioxidant assay. The highest content of ascorbic acid was detected in mature fruits of Heen weralu (66.15 mg per 100 g), while it was lowest (27.30 mg per 100 g) in Pol weralu at ripe. Ascorbic acid contents in RTS drinks Pol weralu and Heen weralu were 13.3 mg per 100 ml and 27.65 mg per 100 ml respectively as compared to 27.30 mg per 100 g and 43.40 mg per 100 g in ripe fruits. The highest value of TSS (17.05) and pH (4) was observed in full ripe Heen weralu. The IC50 (inhibition concentration 50) which represent the antioxidant activity of the methanolic extracts of Po! weralu and Heen weralu were 6.68 and 5.54 mg/ml respectively. Result confirmed that among two varieties, Heen weralu was best in terms of antioxidant activity for both fruit and RTS drink. RTS drink (Heen weralu) was the best sample which showed the highest rank sum value for sensory attributes. Key words: Ceylon Olive (Elaeocarpus serratus), Ascorbic acid, Antioxidant activity, IC50 (inhibition concentration)
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    Effect of Maturation Stage on the Anti-Amylase Factor in Bitter Gourd (Momordica charantia)
    (Uva Wellassa University of Sri Lanka, 2010) Pussewatta, K.G.; Sarananda, K.H.; Wimalasiri, K.M.S.
    Bitter gourd (Momordica charantia) is one of the most nutritive and commercially important cucurbit vegetables, popular due to its medicinal properties. The phenolic compounds containing in the fruits are believed to have an inhibitory effect on amylase activity. It decreases the glucose release during carbohydrate digestion, and therefore considered to exhibit a hypoglycemic effect. This study was carried out to determine the anti-amylase activity of bitter gourd at different stages of maturity and in different parts of the fruit (flesh and seeds). The variety "Thinnavelly white" was used to determine the effect of maturity stage and the composition of fruit (seeds, flesh, seeds and flesh) on anti-amylase activity. Lane-Eynon titration method for reducing sugar quantification was used to quantify the glucose reduction percentage. Precooked white -rice was used as the source of starch. According to the results recommended harvesting stage (by the Department of Agriculture) of Thinnavelly white has the highest glucose reduction percentage (5.73%) in comparison to the commercial stage (5.30%). According to the comparison of the parts of the fruit, combination of flesh and seeds has the highest glucose reduction percentage in comparison to the individual components irrespective of the harvesting stage. According to that, a synergistic effect on the glucose reduction percentage of flesh and seeds of bitter gourd can be expected. Key words: Anti- amylase activity, Hypoglycemic effect, Maturity stages, Harvesting stage, Lane-Eynon titration, Glucose reduction percentage Key words: Anti-Amylase Factor, Bitter gourd, Hypoglycemic
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    Effect of Potassium (KCI) Application on Postharvest Disease Condition and Fruit Quality of Ripe Papaya (carica papaya L.)
    (Uva Wellassa University of Sri Lanka, 2010) Rathnayake, R.P.S.H.; Sarananda, K.H.; Abesekara, C.P.
    Fusarium is one of the most destructive postharvest diseases of the papaya variety red lady. Fusarium species are a weak pathogen and there are several species causing diseases, where Fusarium moniliform is the most common species causing fruit rot in tropical countries. Initially disease symptoms appear as circular water-soaked lesions on ripening fruit which later becomes depressed. At the advanced stage of disease development, the soft rotted area is covered with a white mycelial mat of the fungus. Fungus also penetrates into the tissues of the fruit, causing it to become darker and softer than the surrounding tissues. Nutritional conditions under which the plants are grown have shown significant impact on the disease severity and disease occurrence. In this study four treatments (0%, 2%, 4% and 6% of KCI) were applied as spray solutions in to the papaya fruits three weeks before harvesting. Treatments were arranged in a Randomized Complete Block Design (RCBD). After fruits were harvested they were inoculated with the fungi and kept under the ambient conditions. Then disease severity, disease lesion development and time taken to disease occurrence were observed. Fruit quality parameters were also measured such as TSS (Total Soluble Solids), pH, peel color, flesh color and fruit firmness. Application of 4% KCI significantly reduced the Fusarium rot than other treatments and it also resulted in fruits having the highest pH and TSS values. Treatments with 4% and 6% KCI gave the best flesh color (dark red / red) and highest fruit firmness at the table ripe stage. There was no significant impact of the 4% and 6% KCI on decreasing the percentage of weight loss during ripening and increasing the peel color development. In this study it was found that the continuous increase of KCI levels, beyond an optimum level caused negative impact on fruit quality. Key words: Fusarium fruit rot, Red Lady papaya, Potassium, Fruit quality, Disease severity
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    Effect of Stage of Maturity at Harvest and Artificial Ripening on Postharvest Quality of “Red Lady” Papaya
    (Uva Wellassa University of Srilanka, 2011) Gamage, P.G.N.C.; Ranawana, S.R.W.M.C.J.K.; Sarananda, K.H.; Senarathne, S.M.A.C.V.
    Papaya (Carica papaya L.) is one of the major fruit crop cultivated in tropical and sub-tropical zones. Over 10.48 million tonnes of fruits were produced in 2009 on about 420,279ha (FAO, 2009) worldwide. It is consumed as a table fruit in both fresh and processed forms and cultivated mainly for its nutritive value (Singh, 1990). Tropical fruits are highly perishable and need to be handled with extreme care from the time they are harvested until they reach the consumer. A considerable quantity of production is lost in the postharvest phase. According to the Department of Agriculture, the highest percentage of postharvest loss is found in papaya (46 %) compared to banana and pineapple (20-30 %). Many of the indigenous as well as introduced varieties of papaya fruits are subjected to the post-harvest losses due to a range of disease causing agents such as Fusarium moniliforme,Lasiodiplodia theobroniae, Photnopsis caricae-papayae, and Colletotrichumgloeosporioides. Red Lady is an introduced variety to Sri Lanka from Taiwan. Harvesting, handling and transporting of papaya are very difficult since it is having an easily damageable soft skin. Many people harvest papaya at the immature stage to avoid these physiological damages but those fruits do not ripe correctly and give off flavours. The peel colour and flesh colour also do not develop well and skin gets damaged due to high latex exudation in immature fruits during harvesting. Those damages cause negative consumer preference in the market place. Uneven ripening causes poor quality peel colour and flesh colour in Red Lady papaya. Dark yellow peel colour and the thick red colour flesh in ripe fruits attract the consumer (Sarananda and Wijesundara, 2009). Papaya is oftenharvested at a mature but unripe condition, and is subsequently allowed to ripen further. Under natural conditions, they ripe slowly, lead to weight loss, desiccation and uneven ripening. Thus, fruit ripening is a very important process in order to get good quality ripened fruits for the consumption. This study was conducted to select the best harvesting stage for artificial ripening using Ethrel ((2-chloroethylphosphonic acid), effect of artificial ripening on postharvest quality considering the peel and flesh colour and disease severity of the red lady papaya to minimize the post-harvest losses.
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    Effect of Stage of Maturity at Harvest on Susceptibility to Fusarium Rot in “Red Lady Papaya”
    (Uva Wellassa University of Sri Lanka, 2010) Sivanathan, N.; Sarananda, K.H.
    Main cause for postharvest loss of papaya was pathological rot followed by mechanical injuries. Fusarium fruit rot, caused by Fusarium moniliforme is the main postharvest disease affecting quality of papaya. Disease becomes evident during fruit ripening. Lesions become enlarge rapidly causing a severe postharvest loss. Fruit harvested at different maturity stages colour break, 10% ripen, 25% ripen and 30% ripen. Yellow colour developments were used as treatments to find out the effect of stage of maturity on disease developments. A set of fruits from all maturity stages, were kept at room temperature for ripening. Another set of fruits were inoculated with 0.1x103 conidial/ml and allowed for natural ripening. Percentage weight loss, Peel colour development, Visual quality rating, Disease severity, Lesion development were observed in ripe fruits. The highest percentage weight loss was observed in the 30% ripen stages. Least colour development of peel was observed in fruits harvested at colour break stages. Fruits harvested at 30% peel colour development stages showed the maximum peel colour development. Higher disease severity was observed in fruits harvested at 30% yellow colour stage and it was the minimum in fruits harvested at 10% yellow colour stages. The same trend in all parameters was observed in inoculated fruits with Fusarium spp. Results showed that Fusarium rot in "Red lady" papaya is mainly affected by stage of maturity at harvest. Key words: Red lady papaya, Fusarium fruit rot, Fusarium moniliforme