Browsing by Author "Madushani, R.V.C."

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    Comparative Study on Physicochemical Properties of Sunflower Oil, Palm Oil and Virgin Coconut Oil Available in Sri Lankan Market
    (Uva Wellassa University of Sri Lanka, 2021) Madushani, R.V.C.; Sandarekha, K.A.S.M.; Wijesinghe, W.A.J.P.; Wedamulla, N.E.
    Sunflower oil (SO), palm oil (PO) and virgin coconut oil (VCO) are three different types of widely consumed edible oils, in Sri Lanka. At the time of purchasing the physicochemical parameters among the same oil type can be varied. The study was designed to evaluate the quality attributes of randomly picked oil samples in Sri Lankan local market at the moment of purchasing. Twelve samples (Three brands of SO, four brands of PO and five brands of VCO) of oils were purchased from the supermarkets in Badulla and Colombo area. Specific gravity, viscosity, colour, free fatty acid (FFA) and peroxide value (PV) of all the oil samples were measured. PV and FFA values of SO ranged from 14.80±3.02 meq/kg to 7.67±0.70 meq/kg and 0.86±0.30% to 0.53±0.11%% respectively. The recorded PV values of some brands of SO are complying with the SLS standards and PV values of remaining brands and all FFA values are not complying with SLS standard (946: maximum FFA as oleic acid: 0.25% and maximum PV: 10 meq/kg). Specific gravity, viscosity and colour of the three brands of SO were significantly different (P˂0.05). PV and FFA of PO ranged from 0.36±0.12meq/kg to 0.25±0.02 meq/kg and 11.13±1.43% to 7.07±0.69% respectively. Thus, the recorded PV and FFA of some brands comply with the SLS standards (720: maximum FFA as palmitic acid 0.25% and maximum PV: 10meq/kg). The colour and specific gravity of PO were significantly different (P˂0.05) within the three brands but viscosity was not significantly differed (P˃0.05). PV and FFA of VCO ranged from 3.07±0.17 meq/kg to 2.27±0.13 meq/kg and 0.31±0.03% to 0.20±0.05%, respectively. Thus, the recorded PV values and FFA values are complied with some brands while some are not conformity with SLS standard (32:2002) (maximum FFA as lauric acid: 0.2% and maximum PV: 3 meq/kg). Values for specific gravity, colour and viscosity of three brands of VCO were not significantly different (P˂0.05). In conclusion, the physicochemical properties of some brands in three different oil types do not comply with the SLS standards and also show significant differences within the brands. Keywords: Edible oil; Free fatty acid; Peroxide value; Sunflower oil
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    Effect of Gamma Irradiation on Microbiological and Physicochemical Properties of Dehydrated Carrot (Daucus carota L.) and Dehydrated Ripe Jackfruit (Waraka) (Artocarpus heterophyllus L.)
    (Uva Wellassa University of Sri Lanka, 2020) Madushani, R.V.C.; Wijesinghe, W.A.J.P.; Ranasinghe, R.D.R.; Silva, P.D.P.M.D.
    Dehydrated ripe Jackfruit (waraka) and carrot have a high demand in the local and export market due to their health benefits and the use as ingredients for the food industry. The study was carried out to evaluate the effect of different gamma irradiation doses on physicochemical parameters and microbial quality of dehydrated waraka and carrot in Sri Lanka. Dehydrated waraka and carrot samples were collected and irradiated at doses of 0 kGy, 2 kGy, 4 kGy, 6 kGy, 8 kGy, and 10 kGy by industrial Co-60 gamma irradiator at dose rate 5.3 of Gy min-1 . Under physical parameters, water activity and moisture content were measured for each of the treatments. Total plate count, yeast, and mold count and coliform counts were determined by using ISO modified method. Antioxidant content by following DPPH free radical scavenging method, total phenolic content by following Folin- Ciocalteu (FC) method, and beta carotene content by using AOAC 1980 method was analyzed in all the irradiated samples and non-irradiated samples and all physicochemical and microbial treatments were replicated in three times. The average moisture content of irradiated waraka and carrot samples was 97.04±0.09% and 96.37±0.09% respectively. The average water activity of irradiated waraka and carrot samples was 0.49±0.00 and 0.50±0.00 respectively. Antioxidant activity and total phenolic content of the waraka and carrot samples showed no significant difference (P˃0.05) among different-irradiation doses. However, the content of beta carotene has been reduced (P˂0.05) with the increase of irradiation-dose. Both irradiated waraka samples and carrot samples showed a reduction (P˂0.05) of total plate count with the increase of irradiation dose. There was no growth of yeast and mold and Escherichia coli in all the gamma-irradiated samples. It was concluded that the most preferable irradiation doses for preserving the physical and nutritional quality and microbial safety of dehydrated waraka and dehydrated carrot were 2 kGy and 4 kGy. Keywords: Dehydration, Waraka, Carrot, Gamma irradiation, Dose