Browsing by Author "Wijewardana, R.M.N.A."

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    Development and Quality Evaluation of Avocado (Persea americana) Based Nutritious Supplement Food
    (Uva Wellassa University of Sri Lanka, 2021) Lionel, U.P.L.M.; Wijewardana, R.M.N.A.; Arachchi, M.P.M.; Wedamulla, N.E.
    Postharvest loss of avocado (Persea americana) is very high due to lack of proper indices for maturity detection, seasonality, uneven ripening, and less attention for using product development. This study was aimed to develop avocado-based nutrient-rich supplementary food using dehydrated avocado powder. The avocado fruits in proper maturity were selected and dehydrated using an air dryer(55°C), heat pump dryer(40°C), and freeze dryer(-55°C) followed by blanching and without blanching. The pretreatments (1.5g/L) were used such as citric, ascorbic, combination of citric and ascorbic, and control. The best treatment was selected based on Browning Index (BI). Supplement food was prepared using a different combination of avocado (40%, 50%, and 60% w/w). Proximate composition, physicochemical properties, and sensory properties of the avocado powders and initial physicochemical properties (as; pH, total soluble solids (TSS), lightness (L*), red/green coordinate (a*), yellow/blue coordinate (b*) for the final product was determined. Sensory data were analyzed by Friedman's non-parametric test using 7 points hedonic scale by 20 untrained panelists. Physicochemical properties data analyzed using ANOVA test by MINITAB 17. The lowest moisture (7.57±0.01%) and highest ash (3.86±0.00%) content were recorded by heat pump-dried samples, while the highest crude protein (14.84±0.00%) was recorded by freeze-dried samples, and the highest crude fat (20.31±0.00%) was given by the sample dried using air dryer. A significant difference (P≤0.05) was observed in all physicochemical properties. The TSS content was significantly increased while pH, ascorbic acid content, and colorimetric measures were reduced during the two months of storage period. Heat pump dried without blanching ascorbic acid-treated (BI=56.03±3.28) avocado powder was selected as a qualitatively and economically best treatment for product development based on its properties. Initial physicochemical properties of the product as pH, TSS, L*, a*, b* were 5.67±0.03, 1.53±0.05%, 63.86±0.26, -4.40±0.40, 27.32±0.13 respectively. Based on sensory evaluation the 50:50 avocado powder can be used for product preparation with oats, soybean, Centella asiatica, and vanilla in 25:15:5:5 ratio. The dehydrated avocado powder can be successfully used to develop avocado-based nutrient-rich supplementary food. Further studies are needed to evaluate its shelf life and select a suitable packaging. Keywords: Supplement food; Avocado powder; Blanching; Citric; Ascorbic
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    Shelf Life Extension of Minimally Processed Lettuce Leaves (Lectuca sativa)
    (Uva Wellassa University of Sri Lanka, 2020) Thilakarathna, K.G.C.R.; Wijewardana, R.M.N.A.; Lochana, E.A.L.; Wijesinghe, W.A.J.P.
    Cold storage is one of the best methods to maintain the qualitative and quantitative properties of Minimally Processed lettuce (Lectuca sativa). The study was conducted to optimize the shelf life of minimally processed lettuce which were stored in three different packing materials. Lettuce which was obtained from same cultivation with similar maturity level was stored in Biaxially-oriented polypropylene (BOPP) Antifog 35 micron, Polypropylene (PP) Micro Perforated and Biaxially-oriented polypropylene (BOPP) Antifog Breathable 40 micron at 12ᵒC were evaluated separately for Physiological Loss in Weight, pH, Total Soluble Solids, Total Chlorophyll Content, Ascorbic Acid Content, Total Phenolic Content, Total Anthocyanin Content, Visual Quality Assessment, Total Plate Count and sensory evaluation at the one-day interval. The minimally processed lettuce stored in BOPP Antifog Breathable 40 micron, BOPP Antifog 35 micron, and PP Micro Perforated had shelflife of ten days, eight days, and three days respectively. Lettuce from both BOPP Antifog Breathable 40 micron, and BOPP Antifog 35 micron packs reported a significantly lower physiological loss in weight throughout the storage period. In the tenth day of storage, the lowest total soluble solid (3.7±0.09) was with the BOPP Antifog Breathable 40 micron pack. The highest pH value (6.61±0.03) and total chlorophyll content (2.22±0.04) were recorded in the BOPP Antifog Breathable 40 micron pack on the last day of storage. PP Micro Perforated pack, BOPP Antifog 35- micron pack, and BOPP Antifog Breathable 40-micron pack failed the visual quality assessment on the third day, the seventh day, and the tenth day of storage respectively. The results indicate that BOPP Antifog Breathable 40 micron film is the most suitable packaging material for minimally processed lettuce. Keywords: Lettuce, Minimally processing, Cold storage, Packaging materials