Browsing by Author "Rajapakse, S."

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    Development of a PCR based genotyping procedure to identify the adulterations to beef in Sri Lankan meat market
    (Uva Wellassa University of Sri Lanka, 2013) Dunuwille, S.W.M.B.; Premachandra, T.N.; Rajapaksha, P.; Rajapakse, S.; Sooriyapathirana, S.D.S.S.; Jayawardane, B.C.; Himali, S.M.C.; Kodithuwakku, S.
    Meat is consumed by the Sri Lankan people as a major source of dietary protein. Meat contains over 20 different proteins with a high biological value and contains almost all the essential amino acids (Vercoe et al., 1997). Substitution of an expensive meat type with a cheaper or unaccepted meat type is a major problem associated with the meat industry. Therefore, the determination of food authenticity and the detection of adulteration are important to protect consumer rights (Gupta et al., 2012). Identification of the species of origin of the meat sample is relevant to consumers for several reasons such as possible economic loss due to fraudulent adulterations, medical requirements of individuals who might have specific allergies and religious reasons (Miguel et al., 2004). The beef industry in Sri Lanka is relatively small scale when compared with other countries. The per-capita availability of beef was 1.71 Kg/year in 2011 (Department of Animal Production and Health, 2011). However, a considerable amount of the Sri Lankan population consumes beef and the potential for beef to be substituted by other meat types is higher. Buffaloes are considered as a protected species in Sri Lanka and therefore slaughtering is banned (Animal act, 1958). However, Buffalo meat is often used to adulterate beef. This is mainly because Buffalo meat is comparable to beef in many of the physicochemical, nutritional, functional properties and palatable attributes (Anjaneyulu et al., 1990). Apart from taking buffalo meat as a possible adulterant of beef, this study also tried to distinguish goat meat and dog meat from beef as well using DNA fingerprinting approaches. Methodology Sample collection and DNA extraction: blood samples from Cattle, Goat and Dog and a Buffalo meat sample was obtained. Blood samples were stored at 4°C and meat samples were stored at - 20°C. DNA was extracted from blood samples using the Phenol-Chloroform-Isoamyl alcohol method with modifications (Sambrook and Russell, 2001). DNA was extracted from the meat sample using the Promega Wizard SV Genomic DNA Purification System. DNA samples were quantified using UV absorption spectrophotometer at 260 nm. By using the quantified DNA solutions, working DNA solutions with the concentration of 60 ng/µl were prepared.
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    Production of Bio Ethanol from Sri Lankan Overripe Fruits Using Batch Fermentation and Optimization of Ethanol Yield
    (Uva Wellassa University of Sri Lanka, 2019-02) Kularathne, I.W.; Rathnaweera, A.C.; Kalpage, C. S.; Rajapakse, S.; Gunathilaka, C. A.
    Bio ethanol produced by bio materials are used in many countries around the world as an alternative to gasoline mainly due to better emission characteristics. Since Sri Lanka imports its whole transportation fuel requirement and also committed to reduce greenhouse gas emission, there is a necessity of searching for alternative freely available and low-cost bio resources to produce bio ethanol. The aim of this research was to study the possibility to produce ethanol from Sri Lankan overripe fruits using batch fermentation and then optimization ethanol yield by kinetic modelling. In this research, ethanol production was carried out by fermentation of three different freely available Sri Lankan overripe fruits. Fermentation was carried out by varying fermentation parameters such as type of fruits (banana, papaya, jackfruit), type of inoculums (Saccharomyces Cerevisiae (yeast) and a novel microorganism: Pseudomonas Mendocina (PM)), concentration of the substrate (1:1, 1:1.5, 1:2 w/w ratio of fruit and water), pH (4.3, 5.0, 5.7), and temperature (27, 32, 35 oC). Kinetic modelling was carried out using Monod and modified Gompertz equations. Optimization was carried out by fitting experimental data to the theoretical curves using MATLAB software and then selecting the fermentation process with highest correlation between the theoretical and the experimental curve. The highest correlation was obtained by fermentation banana fruit (embul variety) with PM microorganism, 1:1 w/w concentration at pH value 5 and 35 oC temperature. The concentration of the produced ethanol was 13% V/V. Monod and modified Gompertz equations were well fitted to the experimental data showing higher regression coefficients respectively 99.81% and 99.37%. Compared to the literature a considerable higher ethanol concentration was obtained by fermentation of banana (embul variety) with the novel microorganism: PM than with Saccharomyces Cerevisiae.