International Research Conference of UWU-2019

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Antimicrobial Effect of Immunoglobulin Y (IgY) Extracted from Village Chicken Eggs and Farm Chicken Eggs Against Salmonella
(Uva Wellassa University of Sri Lanka, 2019) Madushika, D.K.L.; Kurukulasuriya, M.S.; Abeyrathne, E.D.N.S.; Silva, G.L.L.P.
Chicken Immunoglobulin Y (IgY) found in egg yolk acts as the main innate immune response against the systemic infections in early stages of chick life. Colibacillosis and salmonellosis are important bacterial diseases which can lead to early chick death. However, the survival rate of indigenous day-old chicks against such diseases is believed to be higher compared to the farm day-old chicks which may have contributed from the IgY activity present in egg yolk. The current study was focused to compare the IgY content in village and farm chicken eggs and to compare the antimicrobial effects of IgY found in both egg types against Salmonella. Six village and six farm laying hens were identified for the egg collection. Gallus Immunotech Chicken IgY Egg Press Purification Kit was used to extract the IgY. Fourier-transform infrared (FTIR) spectroscopy and 10% SDS-PAGE gel electrophoresis under reducing and non-reducing conditions were used to confirm the extracted IgY. Extracted protein concentration (mg mL¯1) of samples was measured using nanodrop spectroscopy. The Mann-Whitey test was used to compare the yield analysis (mg). Antimicrobial susceptibility of extracted IgY was determined against Salmonella sp. isolated from dead day-old chicks. Inhibition reactions of IgY was measured using agar well diffusion assay by turbidity of broth adjusted to the 0.5 McFarland standard. Extracted protein concentration was (7.35±0.92) and (7.12±0.93) in village and farm samples, respectively. Although there was no significant difference, village chicken eggs showed higher IgY yield (132.47±22.31) compared to farm chicken eggs (115.01±17.40). There was no significant different in inhibition zones (mm) of IgY extracted from village (12.1±2.3) and farm (11.3±1.9) chicken eggs. In conclusion, IgY extracted from both village and farm chicken eggs had a similar antimicrobial effect against Salmonella. However, increasing the sample size can improve the accuracy of this preliminary study.
Determination of Antioxidant and Metal Chelating Activities of Water Extracted Lepidocybium flavobrunneum Muscle Protein Hydrolysates
(Uva Wellassa University of Sri Lanka, 2019-02) Kumarasinghe, A.S.U.; Ediriweera, T.K.; Abeyrathne, E.D.N.S.
Lepidocybium flavobrunneum is a marine fatty fish also known as Escolar fish. Due to laxative effect and histamine poisoning many countries reject its consumption as a food leading to wastage of the fishery resources. The objective of the study was to determine the antioxidant and metal chelation activities of Fish Protein Hydrolysates produced from water extracted crude proteins of L. flavobrunneum muscles. In this study Escolar fish muscle was separated from skin and mixed with water according to 1:1, 1:2, 1:3, 1:4 ratios and they were observed under 10% SDS-PAGE gel. Crude extraction was lyophilized and hydrolyzed using Pepsin, Protease and Trypsin enzymes (1:100) under 37 °C at optimum pH conditions for 0, 3, 6, 9, 12 and 24 hours followed by heat inactivation at 100 °C for 15 minutes. Samples were examined for antioxidant activities by TBARS assay, DPPH scavenging assay, and metal chelation activity by Fe (II) chelating activity method, followed by statistical analysis of results. Since there was no any significant different between yields (p>0.05), 1:1 ratio was selected as the best extraction method. 3 hours was selected as the time of hydrolysis, for all enzyme treatments by observing 15% SDSPAGE gel images. According to results obtained from both TBARS assay and DPPH scavenging assay did not show any significance difference (p>0.05). Infact all hydrolysates showed oxidative activities while Fe (II) chelating was high in hydrolysates produced from Trypsin enzyme (37.45±3.33%) compared to rest (p>0.05). Accordingly, the study concluded that hydrolysates produced from incubating with Trypsin for 03 hours followed with heat inactivation has better metal chelating activities compared to other hydrolyzing treatments.
Determination of Antioxidant and Metal Chelation Activities of Sepioteuthis lessoniana (Squid) Ink Hydrolysates
(Uva Wellassa University of Sri Lanka, 2019-02) Fernando, I.H.L.; Ediriweera, T.K.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
Big fin reef squid (Sepioteuthis lessoniana) is a widely distributed species in Northern coast of Sri Lanka and generates 52% of total body weight as waste due to high utilization in processing industry while causing a series of ecological problems and environmental pollution. As these by-products are a potential source of good bioactive compounds, this study aimed to analyze the bioactive properties of hydrolysates developed from squid crude ink. Ink sacs of S. lessoniana were collected and squeezed. Moisture, protein, ash and lipid content in crude ink were analyzed. Trypsin (1:100) was used in the preparation of enzymatic hydrolysates from lyophilized ink at pH of 7.8 by incubating at 37 °C for 0, 3, 6, 9, 12 and 24 hours followed by heat inactivation at 100 °C for 15 minutes. Best time course (3 hours) was detected using 15% SDS-PAGE and directed to develop chemical hydrolysates using 6 M NaOH (basic), 6 M HCl and 6 M Acetic acid (acidic) in 2:1 ratio respectively while incubating at 37 °C for 3 hours followed by heat inactivation at 100 °C for 15 minutes and 15% SDS-PAGE was conducted. DPPH radical scavenging assay was used to detect antioxidant activity while metal chelating activity was used to detect Fe2+ chelating activity in selected best hydrolysates. According to the proximate analysis, moisture and protein contents were 75.53±2.10% and 19.73±2.44% respectively in crude ink. DPPH scavenging assay showed a significant difference between the treatments (p<0.05) and Fe2+ chelating activity assay revealed that there was no significant difference among those three hydrolysates (p>0.05). However, highest DPPH scavenging activity and Fe2+ chelating activity values (61.54±2.96% and 30.35±3.91%) were obtained from acid hydrolysis. Accordingly, the study concluded that hydrolysates produced by incubating with 6 M HCl and 6 M Acetic acid for 3 hours followed with heat inactivation has better antioxidant and metal chelating activities compared to rest.
Determine the Effect of Functional Properties on Chicken Patty Incorporated with Salt Extracted Bioactive Compounds from Pterygoplichthys pardalis (Scavenger Fish)
(Uva Wellassa University of Sri Lanka, 2019) Dissanayake, K.S.M.; Ediriweera, T.K.; Abeyrathne, E.D.N.S.
Pterygoplichthys pardalis is a tropical and invasive fresh water fish. Based on literature, the extracted compounds from this fish consist of anti-oxidative, antimicrobial and Fe2+ chelating activities. Hence, the objective of this study was to determine the effect of these functional properties on chicken patty, incorporated with salt extracted bioactive compounds from Pterygoplichthys pardalis. Female fish were collected from a local reservoir and slaughtered in the field. Gonads (excluding GI tract and mucus) were separated within 3 hours and stored at 4C. Separated parts were followed for extraction of proteins with distilled water (1:4) and then 10% (w/v) NaCl solution (1:4) and lyophilized. Extracted protein samples were incorporated to the preparation of chicken patty (Chicken meat, Salt, Spices) with 0, 0.5, 1, 1.5 and 2% (w/w) levels. Then TBARS assay, DPPH assay, Fe2+ chelating activity and Total plate count were done for the product for Day 0, 2, 4, 7 and 14. According to TBARS and DPPH assay 2% (w/v) incorporation level gave the highest antioxidant activity and Fe2+ chelating activity (p<0.05). Microbial counts of meat patty with 2% (w/v) incorporation level was suitable for 7 days compared with the control (p<0.05). As conclusion, 2% (w/v) incorporation level of salt extraction from P. pardalis can be used as a natural antioxidant, antimicrobial and metal chelating agent in chicken patty. However further studies needed to check for the maximum level of incorporation.
Developing Simple and Economical Prototype to Measure the Internal and External Quality Parameters On Poultry Eggs
(Uva Wellassa University of Sri Lanka, 2019-02) Ranchagoda, B.S.; Udayangani, J.T.C.; Sandaruwan, T.H.S.S.; Wickramarathne, S.D.H.S.; Abeyrathne, E.D.N.S.
Egg quality is based on the characters of an egg that affect its acceptability to the consumer. There are several quality parameters used to identify the quality eggs; both internal and external. Internal quality refers to measuring the egg albumin and yolk distribution and yolk color whereas external quality refers to egg size, weight, shape and shell thickness. According to the quantitative and qualitative parameters there are different grading systems available for measuring quality and classify eggs with different groups and price levels. However, still there is no user friendly and economical method to measure the egg yolk color, shape, weight and shell thickness from a single machine. The study attempts to design a prototype to fill this gap. The egg weight is measured by using load cell which is connected to a liquid crystal display and to the computer. When the egg is placed on the cell the value is displayed both on the computer screen and display. The shell thickness is measured using a digital Vernier caliper. The value is displayed once it is placed between the two arms of the Vernier caliper, which is connected to the computer via an Arduino board. The yolk color and egg shape are measured using image processing techniques. In both processes an RGB image is taken and it is converted to a gray scale image. Then a histogram is developed using the pixel count of each point through length and width. Finally, by analyzing the histogram the output is given. The completed prototype was tested and accuracy was measured. Each feature of the model was accepted by more than 60% of accuracy. After all, a survey was done for testing the user acceptance with the participation of selected 20 poultry farmers, and that accuracy level was appreciated by more than 80% of respondents.
Development of a Ready to Eat Canned Fish Using Underutilized Fish with Different Filling Materials
(Uva Wellassa University of Sri Lanka, 2019) Sathsarani, D.W.N.; Udayathilaka, K.E.; Herath, T.N.B.; Abeyrathne, E.D.N.S.
Fishes are one the most important nutrient sources for humans. Nowadays the demand for ready to eat food is increasing. Present study was to develop a ready to eat canned fish by using underutilized fish. Two fish species, Frigate tuna and Rainbow runner were used and preliminary trials were conducted to find out the best spices level (chili powder, pepper, coriander, garlic, turmeric, cinnamon, ginger, brindle berry cream, cardamom, curry leaves, pandan leaves) and filling solutions (tomato sauce, soy sauce, soybean oil and water) followed by sterilization at 121ºC for different times (50, 65, 70, 75 minutes) using 30 untrained panelists. Colour, texture, aroma, juiciness, mouth feel, overall taste and overall acceptance tested were analyzed by using the 9 point hedonic scale. Best combination of species and filling solutions were subjected for keeping quality analysis by checking pH, lipid oxidation (TBARS and DPPH) and microbial count (TPC, E. coli and Salmonella). According to the sensory data, soy sauce and tomato sauce were selected as the best filling solutions for Frigate tuna and Rainbow runner (p<0.05). Rainbow runner was better in all sensory attributes in tomato sauce and soy sauce compared to the rest (p<0.05). Sterilization for 65 minutes at 121ºC was selected as the best sterilization condition in comparing organoleptic properties (p<0.05). Canned fish produced by Rainbow runner with tomato sauce and soy sauce were selected for keeping quality analysis. Final products were free from E. coli and Salmonella. pH of the soy sauce and tomato sauce range from 5.65±0.19 to 5.75±0.01 and 5.59±0.10 to 5.64±0.11, respectively during storage. Lipid oxidation and TPC were within the acceptable levels during the storage period for 30 days at room temperature. Proximate analysis confirmed that the product is rich in protein. As the conclusion, Rainbow runner fish can be used as one of the best underutilized fish species to produce ready to eat canned products.
Development of a Simple Nontoxic Method to Extract Crude Fish Oil from Yellowfin Tuna (Thunnus albacares) Offal
(Uva Wellassa University of Sri Lanka, 2019-02) Basuru, G.M.V.T.; Kariyawasam, M.G.T.R.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
Among world fish processing industry yellowfin tuna is a dominating species that is responsible for high amount of waste generation during processing which makes a high level of by-product. Fish by-products consist with omega-3 poly unsaturated fatty acids that are vital in food and pharmaceutical industry. The study was targeted to develop an effective fish oil extracting method from yellowfin tuna gut comparing with a current existing extraction technique. The determined proximate composition of yellowfin tuna gut showed 4.87±0.2% of crude fat. The research was conducted with completely randomized design (CRD) with two treatments; wet press method (rendering) and the solvent extraction method. As the solvents Chloroform/Methanol (standard), Acetone, Petroleum ether, n-Hexane, n-Butanol and Ethanol were used separately in 1:2 ratio (Gut sample: Solvent). Finally fish oil yields were calculated on percentages and analyzed the chemical property indices (Iodine value, Peroxide value and Acid value) of extracted fish oil. The results revealed that the highest yield (88.63±2.76%) was obtained in wet press method. In solvent extraction Acetone performed the highest yield (75.26±1.85%) showing the significant difference in comparison with oil yields of Petroleum ether, Hexane, n-Butanol and Ethanol (p<0.05).Iodine value of extracted fish oil from wet press method, Chloroform/Methanol, Acetone, Petroleum ether, n-Hexane, n-Butanol and Ethanol were 109.99±0.57, 103.94±0.56, 104.70±0.47, 104.53±0.74, 103.43±0.37, 106.15±0.86, and 105.83±0.68 respectively. The obtained peroxide value (2.98±0.05) and Acid value (1.04±0.02) of wet press method also indicated higher values than the solvent extraction method which assures that solvent extraction had a low hydrolysis and low oxidation in comparison with the wet press method. As conclusion extraction with acetone is better comparing the quality of the oil extracted.
Development of an Edible Coating Using Crude Sodium Alginate from Sargassum ilicifolium Incorporated with Ascorbic Acid for Minimally Processed Artocarpus Heterophyllus Lam
(Uva Wellassa University of Sri Lanka, 2019) Chandanee, M.R.; Bogahawaththa, B.R.S.; Ranasingha, M.K.; Guruge, K.P.G.K.P.; Abeyrathne, E.D.N.S.
Jackfruit (Artocarpus heterophyllus) lam is a highly available and demanded tropical food because its’ sensory attributes are similar to meat. Many processes involved in minimally processing of Jackfruit lam. However, the challenge is the browning. Therefore, processors are in need of healthy, cost effective ways to minimize the browning. Hence, this study was conducted to minimize the browning in Jackfruit lam using an edible coating from seaweed hydrocolloid. Seaweed hydrocolloid was extracted from highly abundant, locally available, underutilized brown algae species, Sargassum ilicifolium by using sequential biorefinery extraction process. The extracted yield of crude alginate was 31.4% of alga (w/w). Sliced lam was coated using dipping method. Extracted crude alginate, commercial food grade alginate, gelatin with and without ascorbic acid were coated at the room temperature. Citric acid, ascorbic acid treated and uncoated samples were served as the control. Coated samples were stored separately at room temperature (27C) and refrigeration conditions (4C) for evaluate the physiochemical (Browning index, Radical Scavenging Activity, Thiobarbituric Acid Reactive Substances, Color and Texture) microbiological and sensory properties. Sensory analysis was conducted by serving boiled lam without adding any ingredients for 30 untrained panelists with 9-point hedonic scale. The UV spectrophotometric readings were indicated that the coating significantly reduce the browning compared to uncoated lam (p<0.05). Besides that, crude alginate with ascorbic acid were recorded as highest radical scavenging activity in 2,2-diphenyl-1-picrylhydrazyl assay, overall sensory quality, lowest microbial count in total plate count and extend the shelf life for 3 days at room temperature and 2 days under refrigerated conditions. Hence, ascorbic acid enhances the effectiveness of the coating. Then, Jackfruit lam coated with crude sodium alginate with ascorbic acid reduced the browning.
Effect of Selected Wood Smoke on Physicochemical and Sensory Qualities of Tilapia (Oreochromis niloticus)
(Uva Wellassa University of Sri Lanka, 2019) Lelwela, G.K.T.N.; Wijesinghe, S.K.D.; Himali, S.M.C.; Abeyrathne, E.D.N.S.
Different preservation and processing techniques have been used to extend the shelf life of fish. Smoking is a technique that enhances the flavour, colour, texture and shelf life of fish. This study was conducted to identify specific smoking conditions for Tilapia (Oreochromis niloticus) while comparing the physicochemical and sensory qualities of Tilapia smoked using selected wood smokes. Tilapia fillets of same thickness were obtained and trials were conducted to identify the best brine concentration, temperature/time combination and wood material. The fillets were immersed in brine containing 2.5, 5.0, 7.5, 10.0 and 12.5% (w/v) NaCl for 1 hour. Then fillets were smoked with wood smoke under three different temperatures (50, 60 and 70°C) and three drying times (3, 4 and 5 hours) using a smoking oven. Based on the selected temperature/time combinations Tilapia were smoked using mahogany, cinnamon and their combination (1:1). Final products were vacuum packed and stored at 4°C for analysis. Quality changes in sensory attributes were tested with 30 untrained panelists. Microbial quality (Salmonella, Escherichia coli and Total Plate Count), TBARS, DPPH assay, pH and colour were detected during 21 days of chilled storage and proximate analysis was conducted. Fish brined in 10% (w/v) NaCl and smoked at 60°C for 4 hours using mahogany: cinnamon at 1:1 had the best sensory qualities (p<0.05). Microbial counts and lipid oxidation were within the permitted levels. During the chilled storage pH was changed from 6.63±0.09 to 6.70±0.08 (p>0.05). An increase in lightness (40.85±0.32 to 42.02±1.22) was observed whereas the redness (8.86±0.69 to 6.84±0.11) was decreased. In conclusion, immersing Tilapia fillets in brine containing 10% (w/v) NaCl followed by smoking at 60°C for 4 hours using mahogany: cinnamon at 1:1 can be considered as the best conditions to produce smoked Tilapia. However, further studies need to be done to compare the chemical changes occurred due to smoking.
Effects of Hik Tree (Lannea coromandelica) Wax on Internal and Sensory Attributes of Chicken Eggs Stored Under Room Temperature
(Uva Wellassa University of Sri Lanka, 2019) Pushpakumara, P.M.U.; Pitawala, H.M.J.C.; Abeyrathne, E.D.N.S.
To increase the shelf life and to preserve the nutrient content under room temperature mineral oil used as an external coating material for eggs. But it is very expensive and dry slowly than other coating materials. Hik tree (Lannea coromandelica) is a tropical tree grown in dry zone in Sri Lanka and its wax has film forming properties. However, information on Hik tree wax coating on egg quality attributes does not exist. Therefore, this study was done to check the effect of Hik tree wax as an external coating material on shelf life, internal quality and sensory attributes of chicken eggs during storage under room temperature. Total of 306 white, medium sized, clean eggs were purchased from a commercial layer farm in Mahiyanganaya. Eggs were individually weighed and arranged under completely randomized design to 03 different coating treatments as Hik wax (HW), mineral oil (MO), and non-coated (NC) and stored under room temperature (27±2°C) for 6 weeks. Weight losses, Haugh unit (HU), albumen and yolk pH, air sack volume and microbial analysis for Salmonella sp. were determined weekly with 03 replicates. Sensory attributes of eggs were measured using 30 untrained panelists. FTIR analysis was conducted to analyze the structural changes in egg albumen. Results revealed that weight losses were minimum in MO coated eggs than in other treatments (p<0.05). HU decreased from 88.00 to 57.34 significantly in NC eggs compared with HW or MO (p<0.05). Albumen and yolk pH values increased during the storage in all treatments (p>0.05) and air sack volume increased from 0.41 cm to 0.71 cm during storage (p>0.05). However, grade of coated eggs reduced from AA to B within 04 weeks. All coated eggs were negative for Salmonella test during the study period. Color of the egg yolk did not change due to coating material (p>0.05). FTIR data confirmed that no chemical changes occurred due to wax coating. In conclusion, the present study confirmed that Hik tree wax can be used as an external coating material replacing MO.
Evaluation of Antioxidative and Antimicrobial Activities of a Prawn Based Dipping Incorporated with Bioactive Fish Protein Hydrolysates from Pterygoplichthys pardalis
(Uva Wellassa University of Sri Lanka, 2019) Ediriweera, T.K.; Dissanayake, K.S.M.; Abeyrathne, E.D.N.S.
Currently, the world is moving towards functional foods instead of traditional nutrient based foods. “PrawRy” is a value-added prawn and dairy based pre-cooked instant powdered food, which can be processed as a dipping, sauce, salad dressing or as a pudding. Due to its raw materials it is indisputably high in nutrition and its functionalities can be promoted by incorporating bioactive natural compounds. In the present study the “PrawRy dipping”, which was made by cooking for 10 minutes with 1:2 ratio of powder mix (Prawn, milk, butter, garlic) and water, was enriched with pre-proved bioactive salt extracted internal organ (except GI tract) protein (protein: NaCl 10% (w/v) =1:4) hydrolysates of Pterygoplichthys pardalis. Fish protein hydrolysate (FPH) was prepared followed by incorporation of it in to “PrawRy dipping” at 0, 0.5, 1, 1.5, and 2% (w/w) and kept under refrigerated conditions. The bioactivities were then analyzed at 0, 2, 4 and 7 days of storage. Antioxidative properties were evaluated by TBARS, DPPH scavenging assays and Fe (II) chelating activity. Total plate count was detected to check the microbial growth in the final product. According to the results obtained, significant differences were obtained between treatments against non-treated product (P<0.05) in both DPPH scavenging and TBARS assays, Total plate count and in Fe (II) chelating activity assay. Further, significant differences were obtained between days against non-treated product (P<0.05) in TBARS assay, Total Plate Count, Fe (II) chelating activity assay while no such difference was demonstrated in DPPH scavenging assay (except in day 0). The highest antioxidative activity and resistance against microbial growth was demonstrated by 2% (w/w) FPH incorporated “PrawRy dipping”. The study concluded that the “PrawRy dipping” can be enriched with antioxidative and antimicrobial properties by incorporating salt extracted 2% (w/w) protein hydrolysates of P. pardalis as a value-added functional food.
Evaluation of Oxalate Chelating Properties of Selected Egg White Proteins
(Uva Wellassa University of Sri Lanka, 2019-02) Fernando, P.I.L.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
Ovalbumin, ovotransferrin, ovomucin are considered as the major egg white proteins which highly available in the egg white with remarkable functional properties such as anti-bacterial, anti-viral, metal chelating etc. Oxalate also a negative ion and anti-nutritive agent which provides precursor ions to form calcium oxalate kidney stones. According to the present studies, restriction of oxalate rich food is the main prevention factor. A very few studies have been investigated to scavenge the oxalate in the diet. Incorporating egg white proteins to scavenge oxalate will be beneficial, because egg white proteins are well known as natural proteins with many functional properties. Aim of the study was to evaluate the oxalate chelating properties of major egg white proteins: ovalbumin, ovotransferrin (Apo & Halo) and ovomucin. Oxalate (200 mg) were dissolved in 10 ml of distilled water and 0.4 g of proteins were added using triplicates separately. The samples were incubated at 4 °C for 24 hours. After centrifuging, supernatants were measured and directed to the HPLC analysis which has been carried out on RP18 column using the mobile phase of methanol: water (50: 50 v v-1) with the flow rate of 1 ml min-1 and detection wavelength was 237 nm at 1.35 ± 0.5 min retention time. Among the four proteins (P < 0.05), ovalbumin was reported the highest chelating of oxalate (128.43±4.56 mg) and lowest value was shown in apo-ovotransferrin (50.57±1.94 mg). Ovomucin also showed the high chelation of oxalate (94.68±4.24 mg) which less than to ovalbumin. There was a significant difference among the ovalbumin and ovomucin. Whereas the holo-ovotransferrin was shown the oxalate releasing activity. Ovalbumin and ovomucin were shown very good oxalate chelating activity, compare to the apo-ovotransferrin. Therefore, there is a potential to develop nutraceuticals to scavenge oxalate with oxalate chelating properties of these proteins.
Extraction of Crude Coconut Oil from Industrial Coconut Waste and Determination of Its Chemical Properties
(Uva Wellassa University of Sri Lanka, 2019-02) Karunarathne, U.H.D.A.; Alakolanga, A.G.A.W.; Abeyrathne, E.D.N.S.
Coconut oil is one of the highly beneficial natural oil with many of the hidden medicinal values. High amount of low fat coconut residue and sludge water is removed from coconut processing industry without any use. This study was conducted to extract oil from coconut residue and sludge water in order to compare the properties of extracted oil. Oil was extracted from 10 L of industrial sludge water by density separation. Low fat coconut residue was taken and oil was extracted using solvent extraction technique. N-hexane and Di-ethyl ether were two solvents used. Coconut residue (5 g) was taken and both solvents were added separately 1:1, 1:2, 1:3, 1:4 ratios and kept in water bath for 04 different time intervals (2, 4, 6, 12 h) at 37 °C. Later, the solvent was separated from the residue and kept in oven at 40 °C to remove the solvent and the oil was obtained. The physicochemical parameters were determined by standard methods using commercial coconut as control. According to the statistical results, there was a significant difference between the yields of two solvents (p<0.05) with the best yield of for N-hexane in 1:4 ratio with 4 h retention time (20.14%), whereas yield obtained from sludge was 5.00%. Proximate analysis shown that the fat content in residual coconut was 28.33 ± 0.38%. According to the chemical analysis, peroxide (mg peroxide kg-1), acid values and moisture content were 2.85±0.09, 1.39±0.01, 1.26±0.09, 1.59±0.01 and 1.36±0.03, 0.097±0.00, 0.099±0.00, 42.2±1.29, and 1.23±0.00%, 0.99±0.00%, 1.49±0.01%, 9.25±0.02% for commercial oil, hexane, ether extracted oils and sludge oil respectively. The TBARS results showed that oil extracted using hexane have less oxidation than control (p<0.05). This study concludes that low fat residue and sludge water is no longer wastage and it contains significant amount of oil with good chemical properties. However further studies need to check the composition in the extracted oils.
Extraction of Crude Collagen from Thunnus albacares (Yellowfin Tuna) Skin and Determination of Antioxidant and Metal Chelation Activities of Its Hydrolysates
(Uva Wellassa University of Sri Lanka, 2019-02) Thilanja, G.P.D.D.S.; Dissanayake, K.S.M.; Abeyrathne, E.D.N.S.
Collagen is a dominant protein in connective tissues and highly valuable in food industry. Fish processing byproducts are good alternative source for collagen. The objective of this study was to develop a simple non-toxic method to extract crude collagen from Yellowfin tuna skin and to check functional properties of its hydrolysates. Extraction procedures were conducted using acetic acid and citric acid with 0.5 M concentrations. Based on 8% SDS-PAGE gel, type I collagens were identified. Enzymatic hydrolysis was done with Protease, Trypsin and Pepsin enzymes with different time combinations (0 h, 3 h, 6 h, 9 h, 12 h and 24 h) at 37 °C after adjusting to its optimum pH level. Best hydrolysate was selected and subjected to antioxidant activity by Diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity and Metal (Fe2+) chelating activity. Proximate analysis was conducted for raw skin to determine moisture, ash, crude protein, crude fat content and 59.44±0.013%, 1.91±0.37%, 28.55±1.19%, 6.83±0.30% values were obtained respectively. Hydrolysates produced after incubating for 0 h at 37 °C followed with heat inactivation was selected as the best. Hydrolyzed produced using citric acid showed lower scavenging activity (63.62%) compared to acetic acid (85.07%) (p<0.05). In both acetic and citric extractions Fe2+ chelating activity did not show significant difference among the treatments (p>0.05). According to the collagen hydrolysates incubated at 0 h at 37 °C showed good antioxidant activity with acetic acid extraction with Pepsin enzyme. This conclude that collagen hydrolysates produced using acetic acid and Pepsin showed good antioxidant activity comparing with the ascorbic acid as positive control and it could be deserved to use as good alternative source as a natural anti-oxidant in food industry.
Extraction of Crude Skin Collagen from Pterygoplichthys pardalis and Determination of Antioxidant and Metal Chelation Activities of Its Hydrolysates
(Uva Wellassa University of Sri Lanka, 2019-02) Dilhani, E.H.P.U.; Dissanayake, K.S.M.; Abeyrathne, E.D.N.S.
Collagens have a great demand in the food industry and fish skin is a safe alternative source of collagen. Pterygoplichthys pardalis is a freshwater fish which threatens endemic fish and inland aquaculture, and has no economic benefit. Objective of this study was to extract crude collagen from P. pardalis skin with simple and non-toxic method followed by identifying the antioxidant properties of its hydrolysates. Proximate composition was determined in raw fish skins with and without bony plates separately. Acid and Pepsin soluble collagens were extracted from P. pardalis skin. As with the pretreatment process of citric acid (CA) and EDTA were tested to decalcify the fish skin. Three different concentrations were used with CA as 1.2, 2.2 and 3.2 kgm-3 and for EDTA as 0.1, 0.2 and 0.3 M. Selected crude collagens were subjected to the hydrolysis using Pepsin, Protease and Trypsin enzyme after adjusting to its optimum pH with different time combinations (0, 3, 6, 9, 12 and 24 h) at 37 °C followed by heat inactivation at 100 °C for 15 min. Extracted crude collagen and best hydrolysates were selected by 8% and 15% SDS-PAGE respectively. Antioxidant activity of the best hydrolysates was evaluated using DPPH scavenging assay and metal chelation activity by Fe (II) chelating activity. All treatments were replicated (n=3). Raw fish skins with and without bony plates contained 44.29±3.69%, 58.79±1.05% moisture, 16.40±0.93%, 5.38±1.61% ash, 26.75±8.93%, 26.89±3.25% crude protein respectively. Extracted collagens with CA treatment showed higher yield compared to EDTA treatment (p<0.05). The Antioxidant properties were not significantly different (p>0.05) but metal chelation activities of selected best hydrolysates were higher in CA than EDTA treatment (p<0.05). These results conclude that collagen hydrolysates produced from P. pardalis with all three enzymes with 0 h at 37 °C followed by heat inactivation have good antioxidant and metal chelating properties.
Household Egg Consumption Pattern in Kalutara District
(Uva Wellassa University of Sri Lanka, 2019) Chinthaka, A.D.G.; Bogahawaththa, B.R.S.; Mahindarathne, M.G.P.P.; Abeyrathne, E.D.N.S.
Sri Lanka has shown a significant consumer demand increment in the egg industry. The egg consumption trend reflects that the consumers are not only considered about the nutritional value of the egg but also concern about other aspects such as health concerns associated with, food safety and animal welfare issues. In this context, it would be useful to analyze the egg consumption behaviour of consumers that could generate important insights about egg consumption trend of the country. Thus, as a pilot study, the egg consumption pattern in the Kalutara district was studied through a consumer survey. A pre-tested structured questionnaire was used in the data collection and a total of 400 consumers were selected by using the stratified simple random sampling technique. Collected data were analyzed using techniques such as descriptive statistics and correlation analysis in SPSS statistical software. This study revealed that the per-capita consumption of eggs in the Kalutara district (111) is lower than the country average (123). About 6% of consumers are not consuming egg in the Kalutara district. According to the results, most of the consumers preferred free-raised egg (81%) than the farm-raised egg (14%) and they also preferred brown egg (61%) over the white egg (32%). These results indicated that consumers tend to believe that the free raised brown color eggs have a greater nutritive value than white color farm eggs. The study further revealed that the consumers’ perception on health and nutrition did not significantly affect on egg consumption in the Kalutara district. This finding suggests that the consumers are not much aware on the nutritional and health effects related to the egg consumption. However, monetary concerns significantly affected on consumption of egg in families with a lowlevel of income. This finding indicates that the price of eggs is an important concern in facilitating egg consumption among low income groups. This study concluded that there is a lack of knowledge in less educated and low-income families regarding animal protein sources for a healthy life. Thus, it will be useful to conduct awareness programs to inform consumers about the nutritional value of eggs, social stigmas associated with egg consumption and related health concerns.
Identification of Possible Microbial Contamination Points in Bolla Fish (Selar crumenophthalmus) During Storage and Transportation from Kudawella Fish Harbour to Badulla Fish Market
(Uva Wellassa University of Sri Lanka, 2019) Rathnayaka, R.M.M.P.; Dharmarathna, E.K.G.P.U.; Abeyrathne, E.D.N.S.
Improper storage and transportation conditions account for the quality deterioration of fish as it begins to spoil as soon as fish die. Spoiled fish may cause infections to the consumers. Objective of this study was to identify possible microbial contamination points in Bolla fish (Selar crumenophthalmus) during storage and transportation from Kudawella fish harbour to Badulla fish market. Randomly collected fish samples from three control points (before transportation, before unloading and after unloading) including ice samples with three replicates have been examined for the enumeration of total aerobic bacteria, Salmonella and Escherichia coli. Before transportation, the highest total aerobic bacteria count (18.03±0.03 log CFU g-1) was observed in the fish gill samples and the lowest count was observed in fish muscle samples (17.93±0.02 log CFU g-1). Total aerobic bacteria count was increased during first 6 hours after unloading, in Badulla market and after 12 hours bacterial count of fish gill and muscle samples were 18.56±0.01 log CFU g-1 and 18.49±0.01 log CFU g-1 respectively. Initial total aerobic bacteria count of skin swab samples was 18.07±0.01 log CFU g-1 and the count increased at the fish market during last 12 hours to 18.58±0.01 log CFU g-1. All fish gill and skin swab samples collected from the market after 6 and 12 hour intervals were positive for both E. coli and Salmonella and fish muscle samples were positive only for E. coli. Ice samples collected at Kudawella fish harbour and Badulla fish market were positive for E. coli. Control point examination and presence of E. coli revealed that fish arrived to the fishery harbour as primary contamination. Also storage conditions of ice had positive effects on microbiological quality. In conclusion, there is a requirement to initiate sufficient sanitary applications to minimize cross contaminations in fish before reaching to consumer in both fishery harbour and Badulla fish market.
Identification of the Critical Control Points (CCPs) of a Commercially Established Pasteurized Milk Factory in Colombo
(Uva Wellassa University of Sri Lanka, 2019) Ransinghe, H.D.P.; Joseph, R.; Dharmarathna, E.K.G.P.U.; Ranasinghe, M.K.; Abeyrathne, E.D.N.S.
HACCP is a systematic method of identifying, evaluating and controlling all possible hazards associated with a food chain. Implementation of HACCP system has become a necessity for dairy processors to assure the safety and quality of their products. This study was designed to identify CCPs in pasteurized vanilla milk processing line in a commercially established pasteurized milk plant. Preliminary study was carried out to familiarize with the production process while identifying the sample collecting points as raw milk receiving, mixing tank, filling unit and storage. Samples were collected from raw ingredients receiving to the final product. Collected samples were analyzed for physical, chemical and biological hazards. To determine biological hazards, total plate count (TPC), Coliform and yeast and mould tests were done. Adulteration tests for chemical hazards and visual observation for physical hazards were done. According to analysis, physical contaminants were present in raw milk samples. However, no chemical contaminants were detected. Microbiological hazard analysis revealed that TPC and coliform count were high in raw milk samples from bowser. TPC counts of raw milk samples from different milk collecting centers were 7.39±0.31, 7.43±0.27, 7.37±0.31, 7.01±0.20 and 7.40±0.26 log cfu ml-1 respectively while Coliform counts were 5.27±0.48, 5.18±0.55, 5.19±0.31, 5.32±0.37 and 5.23±0.42 log cfu ml-1, respectively. All samples collected before pasteurization were positive for coliform. Post pasteurization contamination was observed in few batches while samples collected after pasteurization were positive for coliform. Post pasteurization contamination was not observed in the rest of the batches. Therefore, receiving of raw milk and the storage tanks of pasteurized milk were identified as the CCPs in the production process. Monitoring and controlling the identified CCPs are really essential to ensure the safety of the final product for the consumers.
Smart Food Safety Management Framework for Small Scale Restaurants
(Uva Wellassa University of Sri Lanka, 2019) Sandipani, H.A.D.C.L.; Dharmarathna, E.K.G.P.U.; Wimaladharma, S.T.C.I.; Abeyrathne, E.D.N.S.
Food safety inspection is a crucial factor in small scale restaurants, to prevent food borne illnesses among the consumers. HACCP is the international tool to manage food safety effectively which can be used as a unique protocol to assure the food safety in any food company. However due to the limited time as a local public health inspector, food safety is a minor concerned subject in their field of working. Objective of this study is to enhance the existing Sri Lankan food inspection process to Badulla area through a developed risk-based food inspection system, which analyze, diagnose and implement main principles of food safety. Interviews with health professionals and pilot survey for small scale restaurants (30) were conducted to understand the existing food inspection programme. Based on that pilot survey, among the targeted group of food handlers most were lack of knowledge on food safety and sanitation. Hence, assessment model based on HACCP for food safety inspection in small scale restaurants was developed. In order to facilitate the end-users to use this developed model, an Android food safety application which consists of optimized user interfaces and offline database was developed. Prototypical development was achieved the user satisfaction in the field level due to its effectiveness and accessibility. As a result, it assures the food safety in small scale restaurants and has potential to improve the food safety practices in food services in the areas covered by the national hygienic and sanitary regulations. Furthermore, “big data” collection through this mobile application can be used for further data analysis, which creates multiple research opportunities.
Study of Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Smoked Fish (Thunnus albacares) Under Different Storage Conditions
(Uva Wellassa University of Sri Lanka, 2019) Uyangoda, D.N.M.; Madage, S.S.K.; Gunasekara, M.M.N.P.; Medis, W.U.D.; Abeyrathne, E.D.N.S.; Jayawardana, J.M.D.R.
Fish smoking is the most extensively used simplest preservation technique. Although, accumulation of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) from wood burning is a major problem associated with the smoked fish. Hence, this research was focused to study the penetration of PAHs in to center of the smoked fish (Thunnus albacares) and effect of accumulated PAHs content with the time under different storage conditions. Fish chunks having equal thickness were smoked using smoke of coconut husk and stored under refrigerated (4C) and frozen (-18C) conditions. PAHs content of surface and center part of stored smoked fish chunks were analyzed at predetermined time intervals by Infinity Quaternary Gradient HPLC system with FLD and UV detectors. Moisture content, water activity, pH, texture, and color of smoked fish samples were also analyzed. PAHs content (Anthracene) of the surface of the smoked fish at the beginning of storage was 190.39 µg/kg and that was declined during both refrigerated (after 6 day 130.09 µg/kg) and frozen storage (after 15 day 106.19 µg/kg). But PAHs content (Anthracene) of the center of the smoked fish at the beginning of storage was 0.00 µg/kg and that was increased during both refrigerated (after 6 day 19.88 µg/kg) and frozen storage (after 15 day 45.47 µg/kg). There were no significant changes in the moisture content (68.49±0.5%) water activity (0.967±0.007), pH (6.04±0.21) and firmness (0.909±0.162 kg) of the smoked fish during the storage (p>0.05). Therefore, results revealed that PAHs penetrate in to the center part of the smoked fish during the storage.

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