Research Symposium-2013

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A Comparative Study on the Diversity of Seagrass Species in a Selected Area of Puttalam Lagoon
(Uva Wellassa University of Sri Lanka, 2013) Ranahewa, T.H.; Jayamanne, S.C.; Gunasekara, A.J.M.
Seagrasses are aquatic angiosperms which are widely spread in shallow marine environment (Kuo and Hartog, 2000). Providing habitat grounds for large numbers of fish and shellfish species, act as a largest carbon sink, support a large number of epiphytic organisms, bind the sediment together and stabilizing sea bottom (Johnson and Johnstone, 1995) are the importance of seagrasses. Puttalam lagoon which is located in Puttalam district of Northwestern Province of Sri Lanka that covers 32700 ha (Johnson and Johnstone, 1995). There are fifteen species of seagrasses have been recorded in Sri Lanka including two families, 12 genera (Amarasinghe and De Silva, 2007). Main objective of the research is to compare changes of seagrass distribution from 1991 to 2013 where as to evaluate relationship between distribution of seagrasses with the states of water quality of selected locations of Puttalam lagoon and to compare the distribution of seagrass species according to salinity levels of each location are specific objectives. Methodology The present study was carried out in selected areas of Puttalam lagoon during the period of May to September in 2013. Kalpitiya, Kuringipitiya, Palliwasalthurai, Kandakuda, Palavi and Puttalam were the selected sites for the data collection (Figure 1). Geographic Position System (GPS) data of the site were recorded and point transect method was used for the sampling. Three line transects of each location were used. Typically transects were perpendicular to the shore and parallel to each other. Cover of seagrasses within a quadrant with 0.5 m * 0.5 m was measured at every 3 m mark of the 30 m by walking and snorkeling until transect was completed. Transects were selected and procedure was carried out in such a way that as same as Jayasuriya, 1991 conducted. Water quality parameters including water temperature (°C), pH, salinity (ppt), conductivity (mS/cm) and dissolved oxygen (mg/L) were measured at the middle of transect two at 10 cm below to the sea surface using Multiparameter meter (Orion Water quality testing was repeated at the same time in the same place once a month and average values were calculated. Same procedure was repeated in other selected locations. Average abundance of seagrass distribution of three transects were calculated. Diversity of seagrass species of each sites were calculated using Shannon - Weiner diversity index. Comparision was conducted using analysis of variance (ANOVA). Percentage abundance of each species were calculated by dividing six sites into two regions as Northwestern and Southeastern according to Jayasuriya, 1991 and compared with the values recorded by Jayasuriya, 1991. Linear regression was conducted to find out relationship between seagrass distribution and water quality parameters.
Comparison of Properties of Leather Made using Plant Oil and Fish Oil as Fatliquors
(Uva Wellassa University of Sri Lanka, 2013) Dunukedeniya, D.M.H.E.; Samaraweera, A.M.; Tharangani, R.M.H.; Wickramasingha, W.
The skin of animal which has been processed to retain its flexibility, toughness, and water proof nature is known as leather (Deluca and Longley, 2008). Leather is a durable and flexible material created via the tanning of animal raw hide and skin, primarily cattle hide. In shoe making process flexibility of the leather is very important. In addition to that leather should be water proof to avoid wearing leather clothes, shoes, hand bags and etc. Major leather making processes involves soaking, tanning, retanning, fatliquoring and finishing (Anon, 2011). Among the steps, fatliquoring is the most critical step in the leather manufacturing procedure. Fatliquoring is the process of introducing oil into a skin following tannage but before the leather is dried (Sivakumar et al., 2007). Therefore, this research was carried out to introduce Castor oil and Gingerly oil as fat liquors as a replacement for high cost fish oil. Methodology This study was carried out at Ceylon Leather Products PLC (CLPLC). The laboratory analysis was done at CLPLC and Uva Wellassa University laboratories. For the fatliquoring purpose, castor oil and gingerly oil were selected according to the lubrication power and unsaturation level of the oil. Then, the selected oils were sulfated using 10% and 20% sulfation levels (Anon, 2011) and were used for the fatliquoring purpose, where fish oil was used as the control. The wet blue of cow hides were selected which used for manufacturing of cow tung lining leather. surface area were selected and divided into five samples. After fatliquoring, retanning, toggle drying and staking was carried out for all treatments with equal time and relevant chemical recipe. Finally, the finishing of leather was done by applying color using hand pad and wax using spray machine. Finally the tensile strength and distention were measured using a universal testing machine and a lastometer, respectively. Then sensory evaluation was conducted to evaluate the softness, fullness, loose grain, oiliness in leather surface and the overall acceptability using 10 trained panelists. The sensory data were analyzed using non-parametric procedure, using the Friedman test incorporated in MINITAB 16 software package. Complete Randomized Design (CRD) was used and data obtained were analyzed using analysis of variance (ANOVA) incorporated in MINITAB 16 with 95% confidence level (p=0.05). Results and Discussion There is no significant difference in distension of the leather versus different fat liquors used (p>0.05). However, the highest and the lowest mean values for distension were given by gingerly oil with 20% sulfation level (according to the weight of the oil) and castor oil with 10% of sulfation level (according to the weight of the oil), respectively (Figure 1). Higher sulfation levels in oil resulted in higher values in distension due to increased penetration ability of oil into the hide (Anon, 2011).
Comparison of Properties of Vegetable Tanned Leather made from Imported Mimosa and Locally Available Tanning Agents
(Uva Wellassa University of Sri Lanka, 2013) Wijethunge, G.P.R.D.; Samaraweera, A.M.; Tharangani, R.M.H.; Wickramasinghe, W.
Leather is a product produced by skins and hides that have been treated to preserve them and make them suitable for use. Leather is a major by-product of meat industry. In Sri Lanka, buffalo, cow and goat hides are used mainly for leather industry producing leather products such as shoes, bags, belts. There are two methods of tanning used in leather production such as vegetable tanning and mineral tanning. In vegetable tanning, plant extracts are used as tanning agent/ tannin and mimosa, an imported product at a high cost is used. In vegetable tanning process there are two types of tannin as catechole and pyragallol (Reed, 1972). Mimosa and tea waste contain catechole tannin and king coconut contains pyragallol tannin. This study was undertaken to find out the properties of locally available tanning agents as an alternative for leather tanning compared to commercially used mimosa. Methodology This study was carried out at the Ceylon Leather Products PLC, Mattakkuliya. Laboratory analysis was done at CLP and Uva Wellassa University laboratories. Cow and buffalo hides were used separately for the leather tanning process. Three tanning agents, mimosa powder, tea waste extract and extract from king coconut husks were used as treatments with three replicates for each treatment. her production process (tanning, bleaching, fat liquoring, drying and plating) was carried ). Tannin extraction from both tea waste and king coconut husk was done manually. King coconut husk was chopped to get tannin extract and tannin density was increased by boiling. Tea waste was boiled to extract tannin from the waste and increased density using high amount of tea waste. During tanning period density and pH of tanning media were adjusted at four days intervals according to the requirement. Tanning penetration and pH changes of the media was measured. Yield, thickness reduction, water absorption, hardness, shrinking temperature and tensile strength were measured in final leather. The sensory evaluation for softness, fullness and overall acceptability of final leather was done using 10 trained panelists. The sensory data were analyzed using non-parametric procedure, according to the Friedman test using Minitab 16 software. Complete Randomized design was conducted and data from tannin absorption, pH changes and properties of leather were analyzed using analysis of variance (ANOVA) procedure of Minitab 16 software. Tannin absorption was different with treatments. Mimosa has the highest absorption rate both in cow and buffalo hides (Figure 1). However, absorption rate was low compared to other day. But considering tea and king coconut it absorption was low at the beginning and then gone high and again low with the time (Figure 2). That could be due to type of tannin and purity of them.
Comparison of the Effectiveness of Fertilizer Produced from Tannery Waste with Synthetic Fertilizer for Plant Growth
(Uva Wellassa University of Sri Lanka, 2013) Asangika, H.L.T.; Samaraweera, A.M.; Herath, H.M.S.K.; Wickramasinghe, W.
Tanning is a process by which hides are converted into leather. There are large amount of waste generated during leather processing. Among them fleshing waste, the removed flesh parts from the limed skin during fleshing operation are produced in large quantities (Rach et al., 1997). Animal fleshing, generated from pre-tanning operations constitute about 50 to 60% among tannery solid wastes that are high in protein (50.9%) and collagen (3.5%) (Anim, 2013). Conversely, nitrogen is the most important nutrient which is required for plant growth (Abubakar et al., 2004). Therefore, animal flesh can be used as a good source of nitrogen for the plant growth and this research was carried out to produce liquid nitrogen fertilizer from fleshing waste generated in the tannery. Methodology Flesh samples were collected from Ceylon Leather Products PLC at Mattakkuliya in Sri Lanka. Enzymatic and Alkaline hydrolysis were done separately to hydrolyze the flesh using Erhavit DMC (a proteolytic enzyme) and carbide lime, respectively. Carbide lime (6%), Erhavit DMC (0.4%) and water (200%) were used according to the weight of the flesh (5 kg each) for hydrolysis at 11-13 pH and 37 C and 5 g of bactericide was added to each mixture. Three replicates were done for each treatment and liquid extracts were collected on day 2, 4, 6, 8 and 10 to measure the Soluble N % using kjedhal method. Liquid extracts which gave the highest nitrogen content (%) were selected from each treatment as liquid N fertilizer. According to the trials liquid extract from day 6 alkaline hydrolysate and day 10 enzymatic hudrolysate were selected. Selected alkaline and enzymatic hydrolysates, urea (positive control) and without any N fertilizer (Negative control), were applied to 14 days old lettuce plants (Lactuca sativa) to check the effectiveness of fertilizer. Equal quantities of phosphorous and potassium were added to all treatments considering the nutrient requirement of the lettuce plant. Four treatments consisted three replicates including three lettuce plants per replicate. Complete Randomized Design (CRD) was conducted and data was analyzed using analysis of variance (ANOVA) and mean comparison was done by Tukey test. Results There is a significant difference among the four treatments and number of leaves of the plant (p<0.05). According to the Figure 1 treatment one was the best because it gave the highest mean value (12.967) compared to other treatments while treatments. Similarly, there is a significant difference among the four treatments and height of the plant in the experiment. According to Figure 2 treatment two was the best because it gave the highest mean value (22.600) compare to other treatments.
Consumer Attitude on Fresh and Processed Meat Quality; A Case Study from Badulla District
(Uva Wellassa University of Sri Lanka, 2013) Karunasena, K.T.S.; Ranasinghe, M.K.; Rathnayake, R.M.S.D.
Worldwide, food safety crisis debates have come forward as an important aspect especially in meat industry. Hence, producers, distributors, marketing staff and policy makers should have higher consideration towards meat quality. Thus, this study was conducted with an aim of identifying the factors influenced on consumer attitude towards meat quality with special reference to Badulla district. Two hundred consumers were randomly selected and interviewed using a pre-tested structured questionnaire. The primary data were analyzed using the Microsoft Office Excel (2007) and Minitab14 software. The Regression model was developed to determine the socio-demographic factors that influence for consumer attitude toward meat quality as, Consumer attitude on meat quality (AI) = f (Age + Religion + Income + Education + Nutritional purpose + Taste purpose + Gender+ Government occupation + Private occupation + Market type). All respondents consumed at least one kind of meat product and 1% of the respondents did not consume any type of meat. Ninety percent of the respondents had established their meat consumption pattern at their child age. The religious believes (55%), economic concerns (16%) and antipathy for killing animals (17%) were the most popular reasons for not being meat consumers. The “meat colour” (80%) was the most concerning factor at the time of purchasing and 20.5% of respondents are concerned of “quality standards” as first. The cleanliness and freshness (30%), tenderness (2.5%), juiciness (1.5%) and marbling (1.2%) were other most concerned quality parameter at the time of purchasing. The income, education level, gender and religion have significantly affected the consumer attitude towards meat quality. There were no significant correlation between the attitude index and age, purpose of meat consumption, occupation and market type. The results showed a positive coefficient of the gender and income level with attitude index.
Designing of a Proper Package to Minimize Trade-Non Vacuum Condition in Vacuum Packed Sausages
(Uva Wellassa University of Sri Lanka, 2013) Ranasinghe, R.A.D.W.; Ranasinghe, M.K.; Jayarathna, S.H.; Boteju, W.L.G.
Food packaging is an integral part of food processing and a vital link between the processor and the eventual consumer for the safe delivery of the product through the various stages of processing, storage, transport, distribution and marketing. The selection of the packaging material has to be done very carefully to protect the different physico-chemical properties like nature of pigments, sensory attributes and micro flora (Marsh and Bugusu, 2007). Due to various types of defects, the return of product causes a considerable reduction of profit annually. Formation of non vacuum condition in vacuum packed products has become one of the reasons for market return. Vacuum packages of pre-cooked sausages, meat ball products create non vacuum condition at different stages from packaging to consumption due to poor mechanical shock resistance of the packaging materials that cause damage during loading, unloading, poor handling, packing and storage (Chainey, 1989). The objective of the study was to design a proper package to minimize the trade non vacuum condition in vacuum packed sausages and minimize the market returns. Methodology Experimental work was conducted at the Keells Food Products PLC, Ja-Ela. Tests for the materials were carried out at the JF packaging (Pvt) Ltd, Kotugoda and the Varna Laminations (Pvt) Ltd, Rathmalana. Initially 4M analysis was conducted in order to identify possible root causes that create non vacuum condition in vacuum packed sausages. Contribution of man, material, method and machine were critically analyzed through observation of machine, handling and transportation system. Five types of coextruded, three layer lamination pouches, varying in thickness as given below were used as treatments for the experiment. T1 = Nylon (15μ)/LLDPE (60 μ) T2 = Nylon (15 μ)/LLDPE (70 μ), T3 = Nylon (25 μ)/LLDPE (60 μ), T4 = both side metalized: PET (10 μ)/MPET (10 μ)/LLDPE (100 μ) and T5 = back metalized and front transparent pouch: PET (20 μ)/LLDPE (100 μ) All the film samples were corona treated and solvent based, prepared according to standard industrial procedure. Twenty samples with three replicates were used for each treatment in the investigation. Each pouch was filled with sausages and subjected to vacuum process. Vacuum packed pouches were stored at -18 ˚C. Treatments were examined for non vacuum condition by visual observation once per week for a month. Each material was analyzed for puncture resistance and tensile strength of films before and after freezing conditions. Data were analyzed using analysis of variance (ANOVA) incorporated in MINITAB 14 statistical software at 5% level of significance. Results and Discussion Non vacuum count for the investigated samples showed a significant difference (p<0.05) indicating that there is an effect of the materials/films for the non vacuum incident. Statistical analysis for non vacuum count have shown that the investigated materials were significantly different (p<0.05) from each other but a significant difference was not found among T4 (both side metalized pouch) and T5 (front transparent and back metalized). The lowest means were recorded in both Treatment 4 and 5 which revealed that the mean non vacuum count is zero in both samples throughout the investigated period. Treatment 4 and 5 were selected for further experiment and were subjected to appearance and customer acceptability test. As revealed by the statistical test there was a significant difference between treatment 4 and 5 (p<0.05) and treatment five was selected as the best treatment (Front transparent PET (20 μ)/LLDPE (100 μ)). Treatment which was consisted of PET (10 μ)/MPET (10 μ)/LLDPE (100 μ) showed higher material performance over other treatments during the storage period. Treatment 4 showed a significant difference (p<0.05) in puncture resistance and tensile strength over other treatments as well as approximately remained stable during the study period compared to other investigated treatments. Statistical data for tensile strength and for the puncture resistance among investigated samples the materials/treatments on the mechanical strength (puncture resistance and tensile strength). Again PET/MPET/LLDPE showed highest performance among others during the study period. It has the highest puncture resistance and the tensile strength over other materials as well as it approximately remained stable during the study period compared to other investigated materials. Therefore again it was selected as the best sample. According to the results of the tukey test any sample similar to the best sample could not be found either for the puncture resistance or for tensile strength (p<0.05) among investigated samples. Conclusions Therefore, treatment 4, PET (10μ)/MPET (10μ)/LLDPE (100μ) and treatment 5, front transparent (PET20μ/LLDPE100μ) can be determined as the best samples among the investigated samples. It can be concluded that metalized films (PET/MPET/LLDPE) which have the highest puncture resistance and tensile strength value was the film that could be used to minimize the market returns due to non vacuuming of the products and could provide best protection against the mechanical damages.
Determination of Efficiency of Crab Shell Powder for the Treatment of Fish Waste Water
(Uva Wellassa University of Sri Lanka, 2013) Wijesundara, A.P.; Rajapaksha, R.M.G.N.; Jayamanne, S.C.; Fonseka, W.R.K.
Water is the most important and basic requirement for life on earth. However, only about 1% of the world’s water can be used for the human consumption. Seafood processing is one of the major industry, which threatens the quality of natural water bodies due to its composition (Zvezdov and Zvezdova, 2010). It elevates the Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Fats, Oil and Grease (FOG) in natural waters and causes eutrophication (Tahir et al., 2013). Some toxic residues may be produced as by-products due to chemical reagents used in conventional wastewater treatment methods, which are toxic for human health and the environment (Gaherwar and Kulkarni, 2012). Hence the utilization of shellfish waste has been proposed as a low cost and eco-friendly wastewater treatment method to solve environmental problems and as a waste management alternative to the masses of shellfish wastes (Muhaemin, 2005). Shells of Portunus pelagicus were used in this study to examine its effectiveness as an adsorbent in treatment of fish processing wastewater. Methodology Crab shells collected from Alpex Marine (pvt)were cleaned and dried at 100 °C for 8 hours using MICHCHEL tray dryer and crushed then sieved to raw powder with 0.1-0.5mm particle size range.50 g of raw powder was heated at 950 °C for three hours in a muffle furnace ( Xy- 1100x-L) to prepare heat treated crab shell powder. Chitin and Chitosan were collected from Industrial Technology Institute laboratory. Wastewater samples were collected from Ceylon Fresh Seafood(pvt) and initial COD (Golterman and Clymo, 1970), pH, temperature (MARTINI pH 55 pH meter), Total Dissolved Solid (TDS) (EUTECH CON 510 TDS meter) and turbidity (TN-100 turbidity meter)values of the wastewater were recorded. The first experiment was done to find out best powder dosage and 5.0 gl dosages were taken from each powder type then placed into 250 ml glass beakers. Then 100 ml of fish wastewater was added to each beaker and stirred for 2 minutes Three replicates were used for each treatment. A beaker containing wastewater only was used as the control. After 24 hours final pH, temperature, TDS, turbidity and COD of treated wastewater were measured using AOAC (1985). During the second experiment initial pH value of the wastewater samples were adjusted to pH 5, 7 and 9 by adding 0.1 M HCl or 0.1 M NaOH. Then selected the best powder dosage from the experiment 1 was used for the second experiment and same procedure was followed to find best pH value which allows highest COD reduction. In the third experiment pH of the wastewater was maintained at the best pH value which was selected from the second experiment. Combinations of Chitosan and heat treated crab shell powder was used in1:1, 1:2, 1:3, 3:1 and 2:1 ratios. Total powder weight in each combination was equal to the best powder dosage which was selected from the first experiment. After 24 hours same procedure was followed as in the early experiments. Finally best powder combined ratio was selected based on highest COD reduction. Significant effect of each treatment was analysed by analysis of variance (ANOVA) using General Linear Model (GLM) procedure of Minitab 16 statistical package.
Determination of Morphological and Genetic Diversity of Wild Guppy (Poecilia reticulata) in Sri Lanka across the MHC Complex with Special Reference to Class IIB Region
(Uva Wellassa University of Sri Lanka, 2013) Godagama, G.R.M.N.; Fernando, T.S.R.; Bulumulla, P.B.A.I.K.; Jayamanne, S.C.
Wild guppies have potential in developing various strains with attractive colour patterns, tail types and tolerance to wide range of environment conditions, resistance to disease conditions due to high immunity. Application of molecular genetic markers, are important to identify diversity among wild guppies which are economically beneficial to ornamental industry and to implement conservation of these valuable genetic resources. Major histocompatibility complex (MHC) genes are highly polymorphic gene family and exon 2 of class II B gene is functionally important in immunity and disease resistance. Hence, in the present study attempts are made to assess the genetic and morphological diversity of wild guppy of Sri Lanka with special reference to immune related MCH class II B gene. A total of 238 wild guppies were collected from 10 regions to represent different agro-ecological zones of the country. The standard length in between 13-24 mm was selected (179 fishes) to collect morphological data and genomic DNA was extracted from muscle tissue using Chelex 100 DNA extraction kit. A PCR based method was used to amplify exone 2 region of candidate gene with forward (5’GTG GAT TTC AGA GAA TAT GCA 3’) and reverse (5’ TGA TTT ATC CAG AGC GGT TTG 3’) primers. Touch down PCR was followed to amplification in the temperature range of 47 to 45 . Selected fish sample consisted of 43.6% of male fishes and 56.4% female fishes. Significant association existed in tail types and colour patterns versus region. Highest variation of tail pattern types was recorded from Buttala region and 40.8% of guppies consisted round tail type. High variation of colour pattern is observed from Badulla region. 58.7% fishes had brownish gray colour pattern and 43% had golden upper body colour pattern. Variation of upper body colour in all regions was similar. PCR protocol was optimized. There was a morphological diversity between wild guppy fishes in different regions of Sri Lanka. Exon II in MHC class IIB region was amplified and optimized PCR protocol for further studies. Sequence variation based on Single Nucleotide Polymorphism (SNPs) and differences of immune response of wild guppy population is yet to be analyzed.
Determination of Sensory, Microbiological, Physio-chemical Quality and Shelf life of Portioned Chicken Meat under Display Condition at Market Stage
(Uva Wellassa University of Sri Lanka, 2013) Nilanka, S.L.P.; Wijesundara, W.M.N.M.; Kekunamullage, P.
Sri Lankan meat processing industry has been rapidly developed since last decade. With increasing market demand they develop various portioned meat products to the market fulfilling the customer requirement. Meat processors recently noticed that during display condition at market stage quality of the products were considerably changed. The aim of this study was to evaluate the physiochemical, microbial, sensory quality changes and shelf life of portioned chicken meat in three commercial brands at display condition (-4 ˚C to +4 ˚C) during 9 days. During the storage period pH value, water holding capacity (WHC), sensory attributes and microbial count were measured in 3 days interval over 10 days. Statistical evaluation was performed using one way ANOVA, general linear model and Friedman test. Gradual and proportional increment of pH values (between 6.14 ± 0.51 and 6.93 ± 0.57) were observed in tested commercial brands of portioned meat samples during the storage time. Furthermore, WHC values were shown significant reduction (between 62.55 ± 0.50 and 55.32 ± 0.02) in all portioned meat samples during the storage time. Total plate counts were increased (p>0.05) in day of storage whereas coliform bacteria also followed the same pattern. However, Escherichia coli were not found in any of sample analyzed. Total bacteria count in portioned chicken meat samples were changed from from day 0 to day 9 of storage. The results showed a gradual and proportional decrease of sensory quality in all portioned meat samples during the storage time (P<0.05). In conclusion, overall results of the study, number and diversity of bacteria species, pH, WHC and sensory quality of portioned chicken meat significantly change with the storage time under display condition at the market level. Also above quality changes significantly difference among three different commercial brands. To assure the quality of portioned chicken meat, it should not exceed five to six days in display condition (kept on -4 ˚C to +4 ˚C) at market stage.
Determination of the Effect of Coconut Shell Extracted Carbon Monoxide on the Quality of Frozen Yellow Fin Tuna (Thunnus albacares) Products
(Uva Wellassa University of Sri Lanka, 2013) Jayasinghe, J.M.P.; Wijesundara, W.M.N.M.; Liyanage, N.P.P.; Wijesena, G.K.C.P.K.
Seafood provides the world's prime source of high-quality protein to the consumers and processed frozen and fresh fish products account for major portion of the diets. Prolonged shelf life and fine quality give the advantages to the frozen fish products in the market and bright red color is used as an indicator of high quality in yellow fin tuna (Thunnus albacares). Carbon monoxide (CO) either alone or as part of a filtered process, is being applied to seafood to maintain the desirable color attributes. CO complexes with the heme-iron of myoglobin, forms a stable red pigment, carboxymyoglobin. The heme-proteins are strong catalysts of lipid oxidation in muscles and reduced heme-protein may suppress the lipid oxidation and other off odour and flavour production (Faustman et al., 1989). CO or filtered smoke is capable of retarding the microbial growth of the muscle (Kristinsson et al., 2008). In Sri Lankan context, coconut shells can be used for processing of filtered smoke with CO. The present study evaluates the effect of coconut shell extracted filtered smoke, a low cost source of CO on the chemical, physical, microbiological and sensory quality attributes of yellow fin tuna (Thunnus albacares). Methodology The study was carried out in a specially designed experimental laboratory of the Global Sea Foods (Pvt) Ltd. Imported grade “A” frozen yellow fin tuna (Thunnus albacares) from 57 Food and Agriculture Organization of the United Nations (FAO) area caught by long lines was used for the study. Average thickness and weight of the processed steaks for the experiment were respectively 22±1.2 mm and 170±6 g. CO was extracted from coconut shells following the Kowalski and William (1999) (United States Patent 5972401) process of making super purified smoke using organic material. CO free, 15%, 30%, 45%, 60% and 75% CO concentrations were used as treatments and CO injected steaks were stored under 4 ˚C for 48 hours and subsequently individually vacuum packed. Complete randomized design (CRD) was adopted for the experiment. Random number table (SLS, 428) was adopted to select the steaks for treatment in five replicates. Treated steaks were stored under -18 ˚C for 2 days and frozen steaks were subjected to analysis for chemical, physical, microbiological and sensory attributes. 15 trained panelists were used for sensory analysis and standards and criteria that were developed by the National Oceanic and Atmospheric Administration and U.S. Department of Commerce (USDC/NOAA) seafood analysts were adopted. All results were reported as means and the significance of the differences were determined by one-way analysis of variance (ANOVA) followed by tukey’s tests for the comparison of data with 5% level of significance. Minitab 16 statistical software and Microsoft Excel 2010 (Microsoft Corp) were used for the statistical analysis. Results and Discussion Chemical, physical, microbiological and sensory quality attributes were analyzed to determine the effect of coconut shell extracted CO on the quality of frozen Yellow fin tuna products. Result showed that there was no significant difference among the histamine level of different CO concentration treated frozen steaks (p>0.05) indicating that decomposition of histidine in to histamine was not affected by the treatment of coconut shell extracted CO smoke.
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.
Development of a Sugar Free Two Bar Ice Palam by Incorporating ‘Kothala Himbutu’ (Salacia reticulata) Stem Extract
(Uva Wellassa University of Sri Lanka, 2013) Surige, D.N.; Abesinghe, A.M.N.L.; De Silva, K.I.U.
Salacia reticulata (Kothala Himbutu) is a woody climber native to Sri Lanka and it is a well known traditional medicinal plant used in Ayurvedic treatments (Anurakumara et al., 2010). Researchers found that the aqueous extract of the roots and stems of S. reticulata has sugar reduction ability and used for treating type II diabetic. Moreover the decoction of S. reticulata is used in the treatment of gonorrhea, rheumatism, skin diseases, hemorrhoids, itching, swelling, asthma, thirst, amenorrhea and dysmenorrheal (Anurakumara et al., 2010). Therefore, it is used in functional food industry and there are several Salacia based preparations available in the market (Ryanghyok et al., 2008). Current study aimed to develop a two bar ice palam which consists with two parts as shell and core. Shell of the product consisting with water ice incorporated with S. reticulata extract and the core comprises sugar free ice cream (lite ice cream).The objectives of this study was to find out the best method to prepare S. reticulata stem extract and to develop a sugar free two bar palam by incorporating S. reticulata extract. The current study was carried out at the Ceylon Cold Stores PLC, Kaduwela. First, the basic composition of the water ice was determined using preliminary trials. Then, water ice was prepared by incorporating S. reticulata stem extract. Several extraction methods were followed to find out the best method to prepare S. reticulata stem extract. The appropriate dosage of the extract was decided according to the Ayurvedic recommendations (Singh and Duggal, 2010) and recommendations of Industrial Technology Institute, Colombo, Sri Lanka. Total soluble solid content for the ice palam incorporated with S.reticulata were adjusted by adding ) in different combinations. Most compatible artificial sweetener combination was determined. Another trial was conducted to select the most compatible flavor of the final product. The best treatments were selected by evaluating the sensory attributes of the product using 7 trained panelists with five point hedonic scale. Then, ) consisting with 6% fat, 30.7% total solid and with a density of 1.09 kg/L. Finally, product was formulated with the developed S. reticulata incorporated water ice as the outer shell and lite ice cream as the inner core. Final product was assembled by GSL machine (GSL wrapper/GSL 12) at -32 °C. pH and the microbiological analysis were done to determine the Aerobic Plate Count (APC), E. coli, Coliform, Yeast and Mould counts of S. reticulata extract for 10 weeks of period under different storage temperatures. Physiochemical parameters and the microbiological analysis were done for the final product. Melting rate of the developed product was determined and compared with a commercially available water ice. A result of sensory evaluation was analyzed by Friedman non-parametric test using MINITAB 15 statistical software program and Microsoft Excel 2010.
Development of Calcium Supplement from the Bones of Yellow Fin Tuna (Thunnus albacares)
(Uva Wellassa University of Sri Lanka, 2013) Gunawardane, K.A.D.D.S.; Thushari, G.G.N.; Jayamanne, S.C.; Malavige, M.
The mineral calcium is mainly important in building of bones and teeth and regulating certain metabolic processes in human body. According to the sources of Health ministry, daily dietary requirement of calcium for adults in Sri Lanka is 750-800 mg. Insufficient intakes of dietary calcium produce hypocalcaemia and osteoporosis (Piratheeban, 2013). Therefore, it is important to use food supplement to enhance the calcium content in various kinds of foods. Fish bones are well known to contain a high amount of calcium and fishbone ash normally contains 34 -36% calcium, particularly calcium phosphate (Hamada et.al., 1995). Yellow fin Tuna (Thunnus albacares) is one of the commercially valued fish species in fish processing industries in Sri Lanka and its’ bones are discarded as waste by processing industries causing environmental pollution. The present study therefore, focuses on developing a method for producing a calcium supplement suitable for human consumption using the bones of Yellow fin Tuna (Thunnus albacares) and reduces accumulation of fish bone as waste causing environmental pollution. Development of a calcium supplement using fish bone will be a new implication in value addition sector of aquatic products in Sri Lanka. Methodology Bones of Yellow Fin Tuna were collected from Global Sea Foods (Pvt) Ltd., Badalgama. Collected samples were manually rinsed to remove adhered muscle residue after transporting to Animal Science laboratory of Uva Wellassa University. The processing steps include pretreatment using NaOH, neutralization, drying, grinding and sifting. Two experimental trials with different treatments were conducted including three replications for each treatment. Trial I was carried out to find out the best NaOH concentration and boiling time combination based on the softness of fish bones (T1- 9%, 80 minutes, T2- 9%, 90 minutes, T3-9%, 100 minutes, T4- 10%, 80 minutes,T5-10%, 90 minutes,T6-10%, 100minutes,T7-11%, 80 minutes,T8-11%, 90 minutes,T9- 11%, 100 minutes).The best treatment was selected by assessing the easiness of grinding 10 g of pretreated fish bones by mortar and pestle for 1 -2 minutes. After neutralization (rinsing by water 7 times), selected best pretreated sample was subjected to Trial II. Trial II was conducted to find out the best time and temperature combination (S1- 80 ºC, 70 minutes; S2-80 ºC, 80 minutes; S3-80 ºC, 90 minutes; S4-90 ºC, 70 minutes; S5- 90 ºC, 80 minutes;, S6- 90 ºC, 90 minutes; S7-100 ºC,70 minutes; S8-100 ºC, 80 minutes and S9- 100 ºC, 90 minutes) for powder form final products. All final products were packed using polyethylene cover and stored at room temperature. Then all final products were analyzed for different parameters. Moisture contents and Drying ) (MR- Moisture ratio, Mt- Moisture content at a specific time, Mo- Initial moisture content, Me- Equilibrium moisture content, k- Drying kinetic rate constants, t-Time) (Techochatchawal et al., 2009) were evaluated for all final samples of Trial II. Calcium content (AOAC Standard Method 927.02) was determined for final treatments of Trial II and most suitable treatment was selected using above parameters. Proximate composition of selected final product was determined for Pb content (AAS, Method 7082), crude fat, ash and crude protein level (AOAC, 1995). Microbiological analysis was conducted using Total Plate Count (TPC) for selected treatment at 37 C. Finally, best treatment was compared with Standards for Supplementary food (Notification of the Ministry of Public Health o.293 B.E. 2548, 2005). Results were analyzed using Kruskal-Wallis test and Analysis of Variance (ANOVA) incorporated in MINITAB 14 soft ware.
Development of Dates (Phoenix dactylifera) Incorporated Probiotic Ice Cream
(Uva Wellassa University of Sri Lanka, 2013) Gunawardena, S.N.P.; Abesinghe, A.M.N.L.; De Silva, K.I.U.
Ice creams are considered as sweetened frozen confectionaries. Today ice creams are modified as functional foods such as probiotic ice cream, low fat ice cream and ice creams with low sugar which deliver the nutritional and medicinal value to the consumer. However, ice cream that is enriched with nutritional and medicinal properties is rarely found in Sri Lankan food industry. Therefore, this study was conducted to fill the gap in Sri Lankan food industry by replacing the cane sugar in ice cream with Dates (Phoenix dactylifera) and by incorporating Lactobacillus acidophilus (LA-5 , CHR Hanson, Denmark) as the probiotic bacteria. Date fruits (Phoenix dactylifera) were incorporated in premium quality dairy ice cream as Cane sugar substitute with the aim of enriching the product with nutritional and medicinal values of Dates. Dates are having total sugar content of 60 -70 g/ 100 g with higher amount of fructose (Anne et al., 2005). Fructose is known as high intensity sweetener (1.7 sweetening power compared to sucrose) with lower glycemic index (Batia et al., 2008). Dates are rich with dietary fiber, vitamin A, B 1, B2, C, iron, potassium, calcium and polyphenols (FAO, 1993). Furthermore, Lactobacillus acidophilus is considered as a probiotic starter culture which confers many health benefits to the consumers by enhancing the microbial balance of the gastro-intestinal tract. Therefore, this study was carried out to develop a Dates incorporated probiotic ice cream. Methodology Research was carried out at Ceylon Cold Stores PLC (CCS), Ranala, Kaduwela. Laboratory analyses were done at CCS and Uva Wellassa University laboratories. Initially, the basic composition of the ice cream was determined. Three preliminary studies were performed to develop the structure of the ice cream as; selecting the best form and level of Dates incorporated in to ice cream and selecting the best level of fat and stabilizer/emulsifier. Three types of Dates were tested as Date pulp, powdered Dates and commercial Date syrup. Best combination of Dates and sugar for ice cream was determined by combining those in different combinations within the range of 13.3% and 28.52%. The best combination was selected by a sensory evaluation using seven trained panelists. After the preparation of ice cream with appropriate texture, two types of flavours; Date flavour (Akras AU 16668) and Rum flavour (Aromco NN15020)were incorporated in to Dates ice cream. Sensory evaluation was conducted to select the most preferred type of flavour in Dates incorporated ice cream. Selected ice cream was used to develop probiotic Dates ice cream by incorporating Lactobacillus acidophilus culture according to the method described by Hekmat and McMahon, 1992. Probiotic culture was incorporated in to ice cream after ageing and heat treatment. Ice cream was aged at 4 C for overnight. Then aged mix was subjected to heat treatment at 82 ºC for 30 seconds and allowed for cooling to 40 ºC. Then it was inoculated with 5-6 granules of freeze C for five hours in incubator. Incubated mix was then subjected for cooling process. When the temperature of the mix decreased to 4 C, it was beaten until desired overrun was achieved. Finally, ice cream was filled into containers and hardened at -18 ºC. Total viable cell count of Lactobacillus acidophilus was determined to find out the survival rate under -18 C using MRS agar (CM 0361, Oxoid Ltd, Hampshire, UK). Then, probiotic incorporated Dates ice cream and Date ice creams without probiotics were subjected to a sensory evaluation using seven trained panelists. Selected type of Dates ice cream was further analyzed for its physicochemical properties and microbiological quality. Proximate composition of the final product was analyzed for fat, total solids, moisture content, crude protein, and ash. Furthermore, Milk Solid Non Fat (MSNF), Brix and pH were measured. Microbiological analysis was done for Escherichia coli, Aerobic Plate Count (APC), Yeast and Mold. Date pulp was analyzed for physiochemical properties and microbiological quality. Melting rate for Dates ice creams were determined and the effect of percentage of Dates and percentage of stabilizer/emulsifier on melting rate were analyzed. Sensory data were analyzed according to the Friedman test using MINITAB 14 software package. Data obtained from melting tests were analyzed by analysis of variance (ANOVA) using SAS 9.1 software package. Complete Randomized Design was conducted for analysis at p˂ 0.005 level of significance.
Development of Standard DNA Size Markers for Short Tandem Repeat Loci BM1818 and BM1824 of Cattle DNA Typing in Sri Lanka
(Uva Wellassa University of Sri Lanka, 2013) Nugapola, N.W.N.P.; Bulumulla, P.B.A.I.K.; Fernando, T.S.R.; Illeperuma, R.J.
Cattle are the most common type of livestock animal raised for meat, dairy, as draft animals and various other purposes. Sri Lankan cattle population mainly consist of indigenous cattle “Sinhala batu cattle”, European pure breeds (Jersey, Friesian, Ayrshire), Indian cattle breeds (Sahiwal, Sindhi, Tharparkar), and their crosses. Identification and traceability of cattle and their products is extremely important for proven of ownership, exploration of pedigree and animal disease control. Traditional identification methods are less effective and associated with many economic, cultural and ethical concerns and are not reliable methods of establishing maternity or paternity of cattle. Deoxyribo Nucleic Acid (DNA) based identification is based on the unique, unalterable, inherited DNA profile of an individual animal as an identifier. Testing the Short Tandem Repeats (STR) of DNA in establishing the identity and parentage is widely used for humans in Sri Lanka. However DNA based identity testing methods are needed to be developed for cattle in order to use it as an accurate method than conventional methods to address problems of cattle identity and traceability. Currently there is no proper procedure of DNA based of identification in Sri Lanka due to the unavailability of standard DNA size markers and there is an urgent need of developing standard DNA size markers for cattle STR (allelic ladders) for accurate genotyping of an individual. Therefore the present study was conducted to develop standard DNA size markers for STR loci BM1818 and BM1824. Methodology Selection of loci Two bovine specific STR markers (BM1818, BM1824) recommended by the Food and Agriculture Organization (FAO) and the International Society for Animal Genetics (ISAG) (FAO, 2011) and previous studies done by Goor and Van de (2011) were selected for this study. Sample collection and DNA extraction Blood samples (n=38) and tissue samples (n=12) were randomly collected from unrelated animals from different areas of the country according to the recommendations provided by FAO 100 extraction protocol described by Phillips (2009) with minor modifications. DNA from tissue samples was extracted by ChargeSwitch Forensic DNA Purification Kit (Invitrogen™, Life Technologies Corporation) according to the kit’s manual. PCR amplification PCR amplification of extracted DNA samples was carried out with 5 µL of genomic DNA in a 50 µL reaction volume, consisted of 5 µL of 10X STR buffer (DreamTaq Green Buffer - Thermo Scientific), 5 µL of each dNTP (Guangzhou Geneshun Biotech Ltd.), 5 µL of primer (FAO, 2011 and Goor and Van de 2011) (Integrated DNA Technology), 0.30 µL of Taq DNA polymerase (DreamTaq-Thermo scientific) and 30 µL of sterilized distilled water. The PCR reaction was carried out in a Veriti 96 well thermal cycler (Applied Biosystem, USA) under the following PCR cycling conditions (Sodhi et al., 2006): 2 min at 94 °C, followed by 30 cycles of 1 min at 94 °C, 1 min at annealing temperature (56 to 62 °C) of each primer, 1 min at 72 °C, and final extension of 10 min at 72 °C. Subsequent to PCR, the products were subjected to 3 % w/v agarose gel electrophoresis to verify the success of the PCR reaction. Then the PCR products were subjected to 7 % denaturing polyacrylamide gel electrophoresis. Amplified products were detected using DNA Silver Staining procedure described by Bassam et al. (1991) and Promega technical manual. Allelic ladder construction Allelic ladders were constructed by two methods as follows (1) DNA samples that can contribute to maximum number of polymorphic alleles to each locus were selected, pooled and amplified by PCR reaction (100 µL reaction volume), (2) PCR products that can contribute to maximum number of polymorphic alleles to each locus were selected and pooled to create the allelic ladders. Results and Discussion According to the Table 1, allelic range of the BM1818 locus was from allele 11 to 21. The highest frequency was shown by allele No.18 at a percentage of 35.0 percent. Allele 11 had the lowest frequency with 1.3 percent. When considering BM1824 locus, allelic range was from allele 11 to 19. The highest frequency was shown by allele No.13 at a percentage of 34.1 percent. Two alleles (11 and 18) showed the lowest allelic frequency of 1.2 percent.
Distribution and Abundance of Seaweeds at Polhena Reef-Matara
(Uva Wellassa University of Sri Lanka, 2013) Ediriweera, A.N.; Jayamanne, S.C.
Polhena reef is among the most valuable marine ecosystems existing along the southern coastal belt of Sri Lanka. The reef is a fringing coral reef and is highly diverse both in flora and fauna. It is well known as an ecosystem that has significant ecological and economical value. Senaratne et al. (2013) has indicated that the reef is exposed to anthropogenic activities and is disturbed to some extent. Coral reef is covered with seaweeds that belong to categories of green, brown and red. Seaweeds also play a major role as live feed, breeding grounds and as habitats for marine fauna existing in coral reef. It is also economically important as human food, animal feed, pharmaceutical, fodder, stationary and cosmetic production. Growth, distribution and abundance of seaweeds vary spatially, seasonally and with other external factors of the environment. This study was focused on the identification of seaweed species, distribution and their abundance within a selected area of Polhena coral reef with an aim of finding their value as an ecological resource. Methodology The study was carried out during the period May, 2013 to July, 2013. An area with a length of 3 km parallel to the shore was selected for the study and five parallel transect lines (T1-T5) were laid across the coral reef perpendicular to shore up to the sea end of the reef using colour coded nylon ropes. An equal distance was maintained between every adjacent two transect lines by using a GPS (Garmin GPS 72). Each rope was marked at each 4 m. Triplicate samples of seaweeds were collected between each and every two marks using a 50 cm x50 cm quadrat and photographs were taken at each quadrat using an underwater camera (Panasonic-Lumix FT-20). Data on species composition and percent cover of the seaweeds that were collected from each quadrat. Species were identified at the laboratory using hand lenses and a binocular microscope (SN090933909 labomed binonular) (Coppejans et al., 2009). Species of seaweeds recorded in five transects during the study period was entered to a table created in Minitab-15 data sheet and Microsoft Excel data sheet. Statistical analysis was done using a Two-way ANOVA, One-way ANOVA and Turkey’s Test in Minitab 15 statistical software.
Effect of Calcium Hydroxide and Poly Aluminum Ferric Chloride Concentration on Water Quality Parameters of Meat Processing Plant Effluent
(Uva Wellassa University of Sri Lanka, 2013) Rodrigo, M.J.M.; Abesinghe, A.M.N.L.; Tharangani, R.M.H.; Liyanaarachchi, B.
As long as the world population continues to grow and demand for food products increase, there are number of environmental and health issues arising. Treatment of both solid wastes and waste water from the meat processing industry has been one of the greatest concerns of the worldwide agro industrial sector, mainly due to the restrictions that international trade agreements have imposed regarding their use and their environmental issues. Many types of substances, when discharged into a receiving body of water, degrade the water quality to such an extent that beneficial uses of the stream are no longer attainable. Normally meat processing plant discharges waste water with high biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS), fat and grease content, turbidity and electrical conductivity (EC). Therefore, waste water should be properly treated before discharging in to the natural water body. Sedimentation and flocculation is one of the waste treatment methods which can be used to maintain water quality parameters within acceptable limits. Poly Aluminum Ferric Chloride (PAFC) is an efficient and cheap flocculent used to treat industrial effluents. However, the efficiency of PAFC is affected by the pH of waste water. Calcium Hydroxide (Ca(OH)2) is one of the alkaline commonly used to maintain pH of waste water (Hammer, 2009). Hence, this research was carried out to determine the appropriate dose of Ca(OH)2 and PAFC for the effluent treatment plant of a meat processing factory. Methodology The current study was carried out at the effluent treatment plant (ETP) of the Gills Food Products Private Limited, Wattala. Laboratory analysis was completed at the chemistry laboratory of Uva Wellassa University. First, ETP was studied well to decide the parameters that need to be changed in order to meet water quality parameters of treated effluent with Environmental Protection Agency (EPA) standards. Selected parameters (dose of Ca(OH) 2 and PAFC) were changed in two separate stages of ETP. Amount of Ca(OH)2 (Ca = 54.092 % (w/w)) was changed at first retention tank and amount of PAFC (Al2O3 = 29 % (w/w), Fe = 4.5 % (w/w)) was changed at the clarifier of the ETP. Laboratory scale preliminary trials were conducted (jar test) to select the effective range of chemicals. Laboratory scale preliminary trials were used for selecting effective weight ranges of two chemicals. The amount of Ca(OH)2 were changed as; 5 kg and 7 kg. The selected amounts of PAFC were 1 kg, 3 kg and 4 kg. Accordingly, there were six treatments as; 5 kg of Ca(OH) 2 and 1 kg of PAFC (T1), 5 kg of Ca(OH)2 and 3 kg of PAFC (T2), 5 kg of Ca(OH)2 and 4 kg of PAFC (T3), 7 kg of Ca(OH)2 and 1 kg of PAFC (T4), 7 kg of Ca(OH)2 and 3 kg of PAFC (T5) and 7 kg of Ca(OH)2 and 4 kg of PAFC (T6). Existing amounts of chemicals were used as the control (4 kg of Ca(OH)2 and 2 kg of PAFC). These combinations were changed once a week. Selected weight of Ca(OH)2 and PAFC were measured using an analytical balance (IND 221, china) and it was dissolved in 20 L of distilled water at ambient temperature. Ca(OH) 2 and PAFC solutions day of the week. The rate of adding chemicals was 150 mL per hour. Water samples were collected at 4 locations of the ETP. Those are discharge point from the factory, first collection tank, clarifier and final discharge point. Collected water samples were used to analyze COD, BOD, Dissolved Oxygen (DO) level, TSS, TDS, Turbidity, EC, pH, temperature and color absorbance for determining the effluent quality for each treatment. A Complete Randomized Design (CRD) was used for the experiment. Analysis of variance was followed by a mean separation procedure using Duncan’s Multiple Range test. Analyses were performed using SAS (SAS institute Inc., Cary, NC, USA). The data obtained were analyzed at 0.05 level of significance.
Effect of Different Preservatives on the Shelf-life of Flavored Lassi
(Uva Wellassa University of Sri Lanka, 2013) Jeyarajah, K.; Abesinghe, A.M.N.L.; Palipana, R.W.P.; Mayurapaksha, A.C.
Lassi is a low fat product that appeals the diet-conscious consumers. It contains probiotic bacteria and sweeteners or flavors. A shelf-life of lassi product is longer than that of milk but its availability is still limited. The purpose of this study is to find out how to extend the shelf-life of lassi. The study was carried out at Island Dairies Pvt (Ltd), Kegalle and Uva wellassa University, Badulla. At first, a series of preliminary trials were conducted to find the most preferable flavored lassi. There were five types of flavors (E 1520); mint salted, mint sweet, Rose, cardamom and pineapple. By using fifty untrained panelists the most preferable flavor was selected. Two preservatives; nisin (0.02%) and potassium sorbate (0.15%) were added. Lassi mixture was prepared by using buffalo curd, sugar, water, salt and permitted flavors following Tamime and Robinson (2007) with slight modification. The curd and water was mixed then sugar, salt flavor and preservatives were added. Then the lassi was blended, homogenized, pasteurized and cooled. The shelf-life was assessed on sensory, physiochemical and microbiological parameters. The selected product was used to measure fat, protein, titrable acidity, total plate count and E.coli. Non parametric data were analyzed using Friedman non- parametric test by MINITAB 15 software and parametric data were analyzed by one way ANOVA (CRD) using SAS 9.1 software. Significant means of treatments were separated using the Least Significant Difference (P< 0.05) test (LSD). According to the sensory evaluation, the pineapple flavored lassi having a significant difference (P<0.05) among five samples regarding appearance, color, texture, mouth feel and overall acceptability was selected as the best treatment. Lassi had a low fat content and the cost of product was Rs 30 per 180 mL. Potassium sorbate scored better than the nisin with comparing pH, Total acidity, Total plate count and cost up to 21 day of storage at 4 C.
Enhancing the Survival of Lactobacillus acidophilus in Acidophilus Milk by Incorporating Maranta arundinacea (Arrowroot) Extract
(Uva Wellassa University of Sri Lanka, 2013) Rizwan, M.R.M.; Abesinghe, A.M.N.L.
Acidophilus milk is a traditional fermented beverage produced using Lactobacillus acidophilus as the starter culture. It has a mild sour taste (Amiri et al., 2010). Lactobacillus acidophilus is one of the probiotic bacteria used in the food industry. The potential health benefits associated with fermented products containing Lactobacillus acidophilus as dietary adjuncts are improved digestion of lactose, control of serum cholesterol, antagonistic action towards pathogens and control of certain intestinal cancers (Maria, 2007; Lampert, 1975). To produce desired benefits, there should be minimum of 10 -10 CFU of probiotic bacteria /gram or mL of product at the time of consumption (Lourens-Hattingh et al., 2001). However, many studies have shown that the number of viable Lactobacillus acidophilus colonies decline with the storage time. This is one of the major limitations faced in the functional food industry. Incorporation of prebiotics such as fructooligosaccharide (FOS) can be used to enhance the survival of probiotic bacteria (Gibson and Roberfroid, 1995). Arrowroot (Maranta arundinacea) is a locally available rhizomatous herbaceous plant which contains 29.1 mg/g of fructooligosaccharides Kaligayahan, 2009). Therefore, the extract of Arrowroot rhizomes may be used to enhance the survival of probiotic bacteria in dairy products. The objective of this study was to assess the effect of water soluble extract of Arrowroot on the survival of Lactobacillus acidophilus in acidophilus milk during refrigerated conditions. This study was conducted at Uva Wellassa University, Badulla, Sri Lanka. Matured arrowroot rhizomes were collected from home gardens of Badulla District. Within a day of harvest, yams were thoroughly washed with running water and cut into cubes (20-30 g). According to Maria et C. Arrowroot samples were grounded with water (1:2) at 27 C in to a pulp. One sample was continuously stirred (100 rpm) for 20 minutes under 40 C and the other sample was maintained under 70 C for another 20 minutes. Then, they were filtered through three layered cheese cloth to remove suspended particles to obtain a clear extract. Similar to Ogunlakin et al. (2012), arrowroot powder was prepared by oven dry method using cleaned and washed Arrowroot cubes at 70°C for 4 hours. Then, they were ground into a powder and sieved. The acidophilus milk was prepared using the method of Yildiz (2010) with some modifications. Standardized cow milk (fat 2.5 %, SNF 8.25%) was used to prepare acidophilus milk. Probiotic culture was prepared using a freeze dried lactic culture (La-5 , Chr. Hansen, Denmark) which contained Lactobacillus acidophilus strain LA-5. There were five treatments according to the type of prebiotics; acidophilus milk with 3% (w/v) powdered Arrowroot rhizomes (T1), acidophilus milk with 45% (v/v) Arrowroot extract (extracted at 70 C) (T2), acidophilus milk with 45% (v/v) of Arrowroot extract (extracted at 40 C) (T3), 2% (w/v) of inulin (Raftilose Sigma Aldrich, USA) (T4) and the control sample without any prebiotics. The best incorporation levels of prebiotics without affecting sensory properties of acidophilus milk were identified by preliminary trials. Arrowroot extract and inulin incorporated cow milk were heated to 95 C for 8 minutes separately. Then they were cooled to 43 C and inoculated with 10% (w/v) LA-5 probiotic culture which contains Lactobacillus acidophilus.
Evaluation of Escherichia coli, Salmonella serovars and Staphylococcus aureus Contamination of Retail Chicken Meat in Badulla District, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2013) Madurangi, G.H.P.; Chandrasena, G.; Fernando, T.S.R.; Wjesundara, W.M.N.M.; Bulumulla, P.B.A.I.K.
Food safety is a global challenge for most developing countries. Food borne diseases are mainly caused by E.coli, Salmonella and S. aureus. And foods originated from animal are more susceptible for spoiling. Thus, the present study aimed at evaluating the Escherichia coli, Salmonella serovars and Staphylococcus aureus contamination in retail chicken meat from Badulla district to analyze the microbiological quality of the retail chicken meat in Badulla District. Twenty retail shops were randomly selected from seven secretary divisions in Badulla district. Two whole chicken samples were collected from each retail shop and transferred to the laboratory under refrigerated condition. 25 g of chicken meat samples from different cuts (breast, back, thigh, wings and whole) were taken. Each meat sample was pre enriched with 225 ml of buffered peptone water and placed in incubator at 37 for 24 hours. Loops full of pre enriched samples were streaked on Eosin Methylene Blue agar, Brilliant Green agar and Manitol Salt agar to isolate of E.coli, Salmonella and S.aureus respectively. Inoculated plates were incubated at 37 for 24 hours. Presumptive colonies on each agar plate, sub cultured on nutrient agar plates and incubated at 37 for another 24 hours. Presumptively positive colonies of E.coli, Salmonella on nutrient agar plates were bio-chemically confirmed with Simmons Citrate agar and S.aureus by catalase test. Prevalence of Salmonella in thigh, breast, back and wing cuts were 28.92 %, 20.48 %, 19.28% and 13.25 % respectively. Prevalence of Salmonella in whole chicken sample was 18.07%. No significance association was observed for the prevalence of Salmonella with different chicken meat cuts (P >0.05). Prevalence of Escherichia coli in thigh, breast, back and wing cuts were 18.99%, 26.58%, 26.58% and 11.39% respectively. Prevalence of Escherichia coli in whole chicken sample was 16.46%. There was a significance association between chicken part and the prevalence of Escherichia coli in retail chicken meat in Badulla District. Contamination rates of S .aureus in different cuts of retail chicken meat were thigh (20.99%), breast (25.93%), back (24.69%) and wing (11.11%). A significant association was observed in prevalence of S. aureus in different cuts of chicken carcass taken from the retail outlets of Badulla district (P<0.05). The highest occurrence of Salmonella was reported in Badulla division (19.28%). Incidences of Escherichia coli (24.05%) and S. aureus (18.52%) were significantly high in Bandarawela division. The findings of this study are vital to the public health risk of the country and emphasis the need of developed programme to assure the quality and safety of poultry meat at retail market

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