International Research Symposium of UWU-2018

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Anti-oxidant Activities of Bioactive Compounds Extracted from Pterygoplichthys pardalis (Scavenger Fish) Harvested at Digana, Central Province, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2018) Perera, B.B.A.N.S.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Pterygoplichthys pardalis (Scavenger fish) survive by competing with native biota. This species is an omnivore whichthreat to endemic fish species and inland aquaculture industry. However, these fishes contain compounds which autolysis proteins under low temperatures. Objective of this study was to check the difference in the water soluble proteins which can be used as bioactive compounds separated from scavenger fish after slaughtering stored at 4 °C for 24 hrs. Female fish (n = 3) were collected from local reservoir and slaughtered in the field. Slaughtered fish which stored at 4 °C were separated in to 4 main components as flesh, GI tract, mucus and other gonads in 0, 3, 6, 9, 12 and 24 hrs of storing. Separated parts were homogenized with distilled water (1:4) and centrifuged to collect the supernatant. Level of separation was observed using SDS-PAGE gel electrophoresis. Then samples were lyophilized and used for further analysis. Antioxidant activity was measured using TBARS inhibitory assay and DPPH scavenging activities. SDSPAGE images confirmed that there were no differences in the extracted compounds after 03 hrs of slaughtering. According to the TBARS assay, three extractions from flesh, mucus and other organs had stronger antioxidant properties compared to the control (p < 0.05). While DPPH scavenging results showed over 75% activity (other organs-91.26±8.28%, flesh- 87.07±4.49%, GI-86.20±3.94%, mucus- 75.20±4.09%) but no difference was observed among the extracted compounds (p > 0.05). Concluding water extracted in 0-3 hrs after slaughtering of female scavenger fish showed strong antioxidant activities and this can be used as natural anti-oxidant agent in food industry.
Antimicrobial Activity of Turmeric (Curcurna longa) Against Salmonella Spp and E. coli Spp
(Uva Wellassa University of Sri Lanka, 2018) Lakmina, D.L.L.; Ranasinghe, M.K.; Abeyrathne, E.D.N.S.; Jayasena, D.K.D.D.
The active components of natural herbs and spices contribute to the self-defense against mechanisms infectious organisms and also getting the attention as alternatives for synthetic chemicals due to their inherent antimicrobial nature, which is primarily used in food preparation. Turmeric is a tropical herb, which use to obtain aromatic powder from its mature rhizomes used for various purposes. The research was conducted to evaluate the Turmeric Methanolic Extraction (TME) and Turmeric Powder (TP) against Salmonella spp and E. coil spp. Dilution series of TME and TP were prepared according to 0.4%, 0.8%, 1.2%, and 1.6% and well diffusion method was conducted. Distilled water served as the negative control while Augmentin® (0.625ppm) served as the positive control. Antimicrobial activity was measured using the diameter of bacterial inhibition zone (DBIZ). TME inhibition for E-coli spp were shown significant difference (P<0.05) between treatments while 1.2% dilution series (DBIZ of 9.6910.54 mm) was closely related to positive control (DBIZ of 9.98±1.57 mm). However, TME inhibition for Salmonella spp did not show significant difference (P>0.05) between treatments. Inhibition of TP inhibition for E-coli spp showed significant difference (P<0.05) between treatments and the best treatment was 0.8% (DBIZ of 1.84±0.10 mm). Moreover, TP inhibition for Salmonella spp showed significant difference (P<0.05) between treatments and the best treatment was 1.2% (DBIZ of 2.31±0.08 mm). In conclusion, 1.2% concentration in both TME and TP samples can be selected as the suitable treatment for antimicrobial property by considering the cost effectiveness.
Antioxidant Activity of the Crude Extract of Ulva lactuca (Sea Lettuce) Collected from the South Coast of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2018) Rumeshani, K.L.G.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Ulva lactuca is one of the famous edible seaweeds around the world. It is a rich source of many nutrients and bioactive compounds. Solvent extraction method is commonly used in extracting bioactive compounds in seaweeds which may be nonfood grade. The objective of this study was to develop a simple, food grade extraction method to extract bioactive compounds from Ulva lactuca and identify the antioxidant activity of the crude water soluble extract and compare with a commonly used solvent extraction method. Four types of seaweed treatments (05 g) namely Fresh, Air-dried (AD), Oven-dried (OD) and Freeze-dried (FD) were used for the water extraction using three different ratios as 1:10, 1:20 and 1:30 and Airdried sample using Methanol as the control. The crude extracts derived from different extraction methods were used for analyzing the antioxidant activity by Thiobarbituric Reactive Substance (TSARS) assay and 2,2-dipheny1-1- picrylhydrazyl (DPPH) free radical scavenging assay. All the trials were done in triplicates. Data were analyzed using the Minitab 18. In TBARS assay, methanol extracts showed the lowest TEARS value (-1.10±0.08) and AD (1:30) and OD (1:10, 1:20, 1:30) showed no significant difference (p > 0.05) compared to antioxidant activity of the methanol extracts. Almost all the samples showed antioxidant activity except Fresh (1:10, 1:20) and AD (1:10). However, In DPPH scavenging assay, DPPH scavenging activity of Fresh (1:10, 1:20, 1:30), AD (1:10, 1:20, 1:30), OD (1:10. 1:30) and FD (1:30) showed no significant difference (p > 0.05) compared to that of methanol extracts. AD (1:10) showed the highest DPPH scavenging activity (89.54±4.56%) which is higher than methanol (87.75±2.87) and Ascorbic acid (85.73±0.19). Therefore it can be concluded that considering the time of production, simplicity, toxicity and cost; water extraction of Fresh (1:10) or AD (1:10) can be used as a best extraction for producing antioxidant agents in food industry.
Antioxidant and Metal Chelation Activities of Fish Protein Hydrolysates Produced from (Scomber japonicus) Pacific Mackerel Canned Fish Processing Fin Wastage
(Uva Wellassa University of Sri Lanka, 2018) Ediriweera, T.K.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Pacific chub mackerel (Scomber japonicus) is a salience fish species which highly utilized in canned fish processing. In production, around 30% of raw fishes are discarded as wastes which lead to economic losses and environmental pollution. Hence, production of Fish Protein Hydrolysates (FPH) utilizing fish wastes, which contains bioactive compounds may be an ideal remedy. In this study Scomber japonicus canned fish processing fin wastage was collected and blended. Aqueous extracts of Fish Protein Concentrates (FPC) were produced with 04 different ratios as sample: distilled water, 1:1, 1:2, 1:3 and 1:4. Crude extraction was observed using 10% SDS-PAGE. Extracted FPCs were hydrolyzed using Papain, Pepsin, Trypsin and Protease enzymes (1:100) under 370C with their optimum pH conditions for 0, 3, 6, 9, 12 and 24 hours followed by heat inactivation at 1000C for 15 minutes. Hydrolyzed samples were lyophilized and observed for antioxidant activities by TBARS and DPPH scavenging assay and metal chelation activity by Fe (II) chelating activity. According to the observations there was no significant difference between the 04 ratios in yield (p > 0.05). So 1:1 ratio was selected with periods as Papain-24 h, Pepsin3 h, Trypsin-3 h, Protease-0 h for further experiments. According to the results obtained from TBARS assay, none of the FPHs showed antioxidant properties (p < 0.05), instead all showed high oxidative activity. However DPPH scavenging assay showed significance difference among the treatments (p < 0.05). Results obtained by Fe (II) chelation activity analysis revealed that the produced FPHs show Fe(II) releasing activity instead of chelation (1.84, 13.99, 16.48, 1.84%,), while FPHs produced according to standard protocol showed a slight chelating activity (0.73%). This concludes the FPHs produced using aqueous extracts of Scomber japonicus do not contain strong antioxidant activity and they have iron releasing properties. Keywords
Antioxidant Property of Peptides Derived from Ovalbumin Using Protease Enzyme under Different Temperature and pH Conditions
(Uva Wellassa University of Sri Lanka, 2018) Madushani, M.A.A.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Ovalbumin is the major and most abundant protein in chicken egg white. Ovalbumin hydrolysates (OVH) have high biological and nutritive value which facilitates the wide use in OVH as dietary supplements and functional foods. The objective of the study was to compare the peptides produced from ovalbumin using protease enzyme with different temperature, time and pH condition and check its' hydrolysates for its antioxidant properties. Ovalbumin was dissolved with 20 mg/mL concentration and hydrolyzed using protease enzyme under different temperature conditions ranging from 37 °C to 50 °C, pH from 6.5 - 8.0 for 0-24 Firs. Level of hydrolyzing was observed with 15% SDS-PAGE gel electrophoresis system and visual observation. Best hydrolysates were evaluated for antioxidant properties using TBARS assay and DPPH Scavenging activity. Based on TBARS assay, all OVH derived under different conditions showed antioxidant property when compare with the oil emulsion (p <0.05). According to the DPPH assay, OVH showed some level (99.37±0.38%, 99.22±3.46%, 98.99±1.24%, 98.97±2.77%, 98.58±2.99%, 98.56±3.39%, 98.54±3.21%) of scavenging activities under conditions of; 37 °C/pH 8.0 (3 hrs); 40 °C/pH 7.0 (12 hrs), 45 °C/pH 6.0 (6 hrs), 8.0 (12 hrs) ; and 50 °C/pH 6.5 (9 hrs), 7.0 (6 hrs), 8.0 (24 hrs). OVH which was produced under 37 °C and pH 8 for 3 hrs had the highest DPPH scavenging activity and was significant difference (p <0.05) among the antioxidant properties observed. In conclusion, TBARS and DPPH values for OVH which were derived under 37 °C and pH 8 for 3hrs conditions have good antioxidant property than the rest. However, applications of these peptides have to be further studied for its' applications in food industry.
Application of Crude Extract of Gelatin from Tilapia (Oreochromis mossambicus) Skin as an Edible Coat for Tomatoes (Solanum lycopersicum var. padma)
(Uva Wellassa University of Sri Lanka, 2018) Lakchani, H.P.M.; Ranasinghe, M.K.; Abeyrathne, E.D.N.S.; Manjula, U.D.P.
Edible coating is an effective method to maintain fruit quality and minimize the post-harvest losses especially in soft skinned fruits. Tomatoes at harvested maturity are more prone to physical impacts during transportation increasing the post-harvest losses. Over the years gelatin has been commonly used as an edible coating due to its barrier properties. Tilapia fish skin as a by-product from inland fisheries is a good source of gelatin. Thus, the present study was focused on application of gelatin based edible coating extracted from tilapia skin for tomatoes. Locally available tilapia skins were used to extract crude gelatin and treated with 5% (v/v) glycerol and applied for tomatoes by brushing at turning stage under room temperature. Non coated tomatoes were used as the control. Both coated and noncoated tomatoes were stored at room temperature for 25 clays of storage in opened polyvinyl boxes. During storage, samples were evaluated for pH, weight loss, color (L*, a*, b*) , titratable acidity, total soluble solids, hardness and sensory attributes at 3-day intervals. Weight loss, color, total soluble solids, titratable acidity and hardness of coated tomatoes showed significant differences (p <0.05) than those of non-coated tomatoes. However, pH and titratable acidity were not significant (p >0.05) between treatments. Sensory analysis was done by 30 untrained panelists and results revealed that the use of edible coating positively influenced on overall acceptability of coated tomatoes until 24th day whereas non coated tomatoes had an unacceptable quality at 18th day. In conclusion, application of crude extract of gelatin on tomatoes showed delayed ripening with acceptable quality parameters for 24 days at room temperature.
Comparison of Antioxidant Activity of Hydrolysate Products of Crude Collagen Extracted from Chicken Egg Shell Membrane Using Different Methods
(Uva Wellassa University of Sri Lanka, 2018) Dissanayake, K.S.M.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Collagen is a highly valuable protein used in food industry. Egg shell membrane is a safe source for collagen. Extraction of collagen from chicken membrane and producing its hydrolysates were carried out using different methods. Objective of this study was to extract collagen from chicken egg membrane with simple and non-toxic method followed by hydrolysis to find out the functional properties of the hydrolysates. Shell membrane was separated by manual peeling by adding 0.5 M Acetic acid, 0.5 M Citric acid followed with extraction of collagen with pepsin digestion. pH of the extracted collagen was adjusted to 6.5 and hydrolyzed using protease with different time combinations (0, 3, 6, 9, 12, 24 hours) at 37 °C followed by heat inactivation at 100 °C for 15 min. Best hydrolysates were selected by 10% SOS-PAGE by visual observations. Selected hydrolysates were subjected to antioxidant activity by Thiobarbituric Acid Reactive Substances (TBARS) method and Diphenyl-l-picryhydrazyl (DPPH) radical scavenging activity. The highest collagen yield was observed from citric acid (0.15 g 1 0g-1) extraction than acetic acid (0.08 glOg-1) treatment (P > 0.05). SOS-PAGE did not show bands even 0 hours, so, 0 hour hydrolysates were selected for antioxidant testing. In DPPH analysis, citric acid extraction shows higher scavenging activity (96.79%) than acetic acid (72.37%) (P < 0.05).flowever in TBARS method also did not show significant difference among the treatments (P > 0.05) and it showed 0.00 mg 1.1level of Melonaldehyde. This concludes that collagen hydrolysates showed good antioxidant activity with citric acid extraction than acetic acid extraction comparing with the ascorbic acid as positive control which can be used as a natural antioxidant in food industry.
Comparison of Lipid Profile of Smoked Catla (Carla Calla) Made Under Different Combustion Conditions
(Uva Wellassa University of Sri Lanka, 2018) Sumanathilaka, A.H.T.N.D.; Abeyrathne, E.D.N.S.; Alakolanga, A,G.A.W.
Fish lipids are considered as one of the major sources of polyunsaturated fatty acids including docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. Since fish is a highly perishable food item, preservation techniques are needed to keep the quality of fish at a higher level for longer shelf-life. Smoking is one of most popular fish preservation techniques and during which lipid profile of fish may be changed resulting in the reduction of nutritional value of fish. This study was conducted to compare the lipid profile of smoked fish made under different combustion conditions. Medium sized (2-3 kg) male Catla fish (Calla calla) were selected from a local reservoir in Ampara district. Fish were brought to the laboratory under chilled conditions and fish fillets were prepared for smoking. Smoking was carried out at 45 ℃ for 2-4 hours. Mahogany, Paddy straw, Cinnamon and Gliricidea were selected as the combustion materials according to the availability and low cost. Lipid extraction was carried out from the smoked fish samples. The composition of lipid extracts of smoked fish were compared with the lipid extract of raw fish by Gas Chromatography-Mass Spectroscopy method and Thin Layer Chromatography method. The level of unsaturation was compared by calculating iodine, acid, peroxide and saponification values. Smoke was collected from the combustion materials and analyzed using Gas Chromatography-Mass Spectroscopy to determine the composition of the smoke. Results showed that there was a significant difference (p <0.05) in the level of unsaturation between the lipid extracts of the smoked fish and raw fish. According to the chromatogram obtained from Gas Chromatography, there was a significant difference in the predominant fatty acids between the lipid extracts of raw fish and smoked fish. In concluding the results, during the processing of fish, chemical changes occur which change the nutritional value of fish.
Determination of the Organoleptic Properties of Hydrolyzed Ovalbumin Incorporated Dry Cured Ham
(Uva Wellassa University of Sri Lanka, 2018) Gunasekara, D.P.M.K.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Ham is one of the most popular cured meat products used all over the world. Potassium and sodium salts of nitrite and nitrate are commonly used as a preservative agent and color enhancer in dry cured ham production. However, high use of these chemicals may lead to health risks. Ovalbumin is the major chicken egg white protein that can be used to produce several bioactive peptides with various functional properties. Objective of this study was to use these peptides as a nitrate replacer in dry cured ham. Dry cured ham was produced incorporating nitrite: ovalbumin hydrolyzates in ratio of 0:0 (no curing salt, as negative control, Tr1), 0:100 (Tr2) 125ppm nitrite as positive control, 0:100 (Ovalbumin,Tr3), 0:100 (Hydrolyzed Ovalbumin,Tr4), 50:50 (Tr5), 75:25 (Tr6) and 25:75 (Tr7). Ovalbumin was hydrolyzed using pepsin (1, Enzyme: 100 Substrate) at just after incubation at 37°C followed by heat inactivation (15 min/100°C). Prepared ham samples were vacuum packed and stored under freezing condition [-18°C] for further analysis. Sensory analysis was carried out by 30 untrained panelists. Antimicrobial activity was tested for locally isolated Escherichia coli and Salmonella. Keeping quality was checked with pH and TBARS assay with 03 days intervals up to 40 days. Color of the samples was initially measured using a colorimeter. According to the sensory analysis, there was no significant difference in overall acceptability among the treatments (p>0.05). Taste was better in positive control (p<0.05). Redness and lightness were significantly different between treatments (p<0.05), yellowness of the treatment did not show any difference (p>0.05). pH and the level of oxidation were within the acceptable range among the treatments during the storage period. It can be concluded that peptides derived from hydrolyzed ovalbumin can be used as an effective curing salt replacer for dry cured ham.
Development of a Value Added Canned Fish Product Using Rough Trigger Fish (Canthidermis inaculatus)
(Uva Wellassa University of Sri Lanka, 2018) Jeewanthi, J.W.P.C.; Mahaliyana, A.S.; Udayathilaka, K.E.; Abeyrathne, E.D.N.S.
Fishes are one of the excellent nutrient sources for human. Fish canning is used as preservation technique to reduce spoilage. Improper continuous supply of mackerel to produce canned fish is the main problem in canned fish production. Objective of this research was to develop a value added canned fish product using Rough Trigger fish as an alternative to mackerel. Canning was done under commercial conditions in a fish canning company. Trials were carried out to select the best brine concentration and spices added. Another set of trials were done to compare the brine and oil filling. Based on the sensory evaluation the best treatment was selected using the 30 untrained panelists. Taste, color, aroma, texture, mouth feel and overall acceptability were checked. The final product was subjected to keeping quality analysis by determining the pH, level of oxidation and microbial contamination. According to the trials, 2.5% (w/v) brine solution was selected as the best brine percentage. Aroma and color did not show any significant difference among the treatments (p>0.05) and texture, mouth feel, taste and overall acceptability had significant difference (p<0.05). Similarly 2.5% (w/w) pepper and 0.25% (w/w) cinnamon was selected as the best level of spices to be add in to the final canned fish. According to the sensory data coconut oil was selected as the best oil to be used. Salmonella and E coli were absent in all treatment. pH of the treatment were ranged from 5.79± 0.18 to 6.26±0.18 for 21 days and it was within the acceptable range. Results from TBARS assay showed significantly (p<0.05) low oxidation in brine added canned fish than oil immersed canned fish until 21 days. In conclusion, 2.5% (w/v) brine, 2.5% (w/v) pepper and 0.25% (w/v) cinnamon added canned Rough trigger fish can be a good replacer for mackerel canned fish.
Evaluation of Anti-Bacterial Activity of Hydrolyzed Ovomucin Using Fish Pattie Produced from Tilapia (Oreochromis mossambicus)
(Uva Wellassa University of Sri Lanka, 2018) Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Fish patties contain higher amount of essential nutrients. Ovomucin is an egg white protein and can be used to produce bioactive peptides with various functional properties. This study was conducted to determine the effect of hydrolyzed ovomucin on the survival and growth of Salmonella sp. and Escherichia coil in vacuum packed fish patties made from Tilapia (Oreochromis mossambicus) during storage at -18°C for 28 days. Ovomucin (20 mg/ml) was hydrolyzed with heat inactivation at 100°C for 15 min. Fish patties contained fish (64%), bread crumbs (17%), ice (12%), vegetable oil (4%), salt (2%) and spices. Seven different treatments including ovomucin hydrolysate and curing salt in ratio of 125 ppm: 0 (as positive control), 0:100 ppm (Tr1), 62.5 ppm: 62.5 ppm (Tr2), 31.25 ppm: 93.75 ppm (Tr3), 93.75 ppm: 31.25 ppm (Tr4), 125 ppm of ovomucin (Tr5) and no additives (as negative control) were prepared as above mentioned procedure. Samples were cooked at 80°C to reach a core temperature of 72°C and cooled in cold water. Samples containing hydrolysates showed significant (P<0.05) antimicrobial activity compared with negative control. However, the effect of Tr2 on Salmonella growth inhibition was higher than other treatments. Similar effects were found with E. call growth inhibition. The combined antimicrobial effect of curing salt and hydrolyzed ovomucin was higher than using them alone, in both contaminated samples. Generally, all tested food-borne microbes were significantly (P<0.05) affected by adding curing salt and hydrolyzed ovomucin. It can be concluded that antimicrobial activity on foods can be much stronger when incorporated hydrolyzed ovomucin with curing salt. In addition, hydrolyzed ovomucin can be used as a prospective natural replacement of curing salt by 50% which is currently used in processed fish products.
Evaluation of Physiochemical Changes in Raw Chicken Eggs Stored at Room Temperature
(Uva Wellassa University of Sri Lanka, 2018) Pathirana, H.H.R.; Aruppala, A.L.Y.H.; Pitawala, H.M.J.C.; Abeyrathne, E.D.N.S.
Chicken eggs are widely used in the world, due to perishability which undergoes deterioration with the time. This affects with egg processing industry and to economic losses. In this study, physiochemical changes of raw chicken eggs (RCE) stored at room temperature (28-31 °C) were determined. A total of 60 medium sized white shelled RCE obtained from 61-wk old Hyline White hens were analyzed for weight loss (%), yolk color, Haugh unit, USDA grade, pH of egg yolk and egg white and Fourier transform infrared (FTIR) spectrums at 0, 1, 4, 8, 12, 16, 20, 24, and 29 days Microbial analysis for Salmonella was checked at 0 and 29 days of storage. Weight loss (%) and pH of egg white and yolk increased whereas Haugh unit and USDA grade decreased at 29th day. Yolk color significantly increased (p < 0.05) from 12 to 14 and weight loss (%) increased (p < 0.05) from 0 to 6.27 with the storage time. However, Haugh unit showed a significant decrease (p < 0.05) from 85.13 to 40.33 and USDA grade significantly decreased (p < 0.05) from AA grade to B grade during 29 days of storage. Albumin pH and yolk pH significantly increased (p < 0.05) from 8.81 to 9.59 and from 5.77 to 6.43, respectively. Salmonella was not observed in RCE during storage at room temperature. FTIR spectrums indicated changes occurred in bonds of Amide A (3304 cm-1), Amide I (1637 cin-1), Amide II (1547 cm'), Amide III (1238 cm'), Amide IV (594 cm l), Asymmetric CH3 Stretching (2925 cm') and Symmetric CH2 Stretching (3304 cm-1). Moreover, secondary structural changes were detected in protein in RCE during the storage. In conclusion, RCE showed significant physiochemical changes in weight loss, Haugh unit, albumin pH, yolk pH and chemical structures during the storage period upto 29 days at room temperature. Keywords
Evaluation of Physiochemical Changes in Un-Boiled Eggs Stored at Different Temperatures
(Uva Wellassa University of Sri Lanka, 2018) Eregama, G.R.S.R.; Aruppala, A.L.Y.H.; Pitawala, H.M.J.; Abeyrathne, E.D.N.S.
Eggs are considered as powerhouse of nutrients and also it is very popular food in the world due to its nutritional value. Among that, hard boiled eggs are widely used in ready-to-eat food processing industry. However, storing of hard boiled eggs under refrigeration and freezing conditions lead to some problems including rejection of customer demands due to its textural changes. Objective of this study was to check the effect of storing temperature on textural changes in un-boiled egg white with time. Medium sized brown shell eggs collected from commercial layer farm and stored under room temperature (27 °C), refrigeration (4 °C) and freezing (18 °C) conditions for 0, 6, 12, 18, 24 and 48 hours. Then the stored eggs were boiled for 100 °C for 15 minutes and egg properties were studied under Fourier Transform Infrared (FTIR) spectroscopy (ALPHA), texture profile analysis using Texture analyzer (CT3), visual observation done by using gemological microscope and color was measured using colorimeter (CR 410 Chromo meter). Sensory qualities of boiled eggs were measured using 30 untrained panelists. According to the results, frozen eggs were showing low acceptance in all organoleptic properties checked (p<0.05). Hardness and gumminess of eggs were effected significantly during the storage in frozen eggs from the rest of the treatments (p<0.05). FTIR spectrums also confirm that the textural changes in bonds of amide A (3271 cm-1), amide I (1626.2 cm-1), amide II (1539.0 cm-1), C=O stretch of COO- (1397 cm-1), asymmetric PO2- stretch (1240 cm-1). However, the color of the egg white was not significantly different (p>0.05) among treatments. Sensory results revealed that frozen eggs after 12 hours did show low acceptance comparing the rest. As a conclusion storing temperature of un-boiled eggs has an effect on the texture of eggs after boiling.
Extraction of Crude Bone Collagen from Yellowfin Tuna (Thunnus albacares) and Determination of Anti-oxidative Activity of Its Hydrolysates
(Uva Wellassa University of Sri Lanka, 2018) Wijekoon, W.M.M.P.; Aruppala, A.L.Y.H.; Kariyawasam, M.G.T.R.; Abeyrathne, E.D.N.S.
Fish bones are significant part of fish processing by-product and rich source of collagen proteins. Utilization of yellowfin tuna bones are important economically as well as environmentally. Objective of this research was to extract crude collagen from yellowfin tuna bones and to identify the anti-oxidative activities of its hydrolysates which can be a potential natural anti-oxidative agent in food industry. Acid-pepsin soluble collagens were extracted from fresh yellowfin tuna bones. As with the pre-treatment process EDTA and citric acid were tested to decalcify. Extracted collagens from two treatments were subjected to the hydrolysis using protease enzyme with different time combinations (0, 3, 6, 9, 12, 24 h) at 37 °C followed with heat inactivation at 100 °C for 15 minutes. Antioxidant activity of the best hydrolysates were evaluated using thiobarbituric acid reactive substances (TBARS) assay and 2,2-dipheny1-1-picrylhydrazyl (DPPH) free radical scavenging activity method. All treatments were replicated (n = 3). Resulting extracts with citric acid treatment (1.23±0.05%) showed higher yield compared to the EDTA treatment (0.62±0.18%) (p < 0.05). Both treatments showed similar band patterns with 08% SDS-PAGE gel electrophoresis confirming the extracted collagen are same. Hydrolysates produced after incubating for 3 hours at 37 °C followed with heat inactivation was selected as the best (p < 0.05). The results showed that collagen hydrolysate of yellowfin tuna bones inhibited lipid oxidation in oil emulsion system and also control free radicals (DPPH). TBARS results of EDTA and citric acid treatment showed no significance difference with the control(p > 0.05). EDTA (86.14±1.88%) and citric acid (87.92±7.72%) treatments showed DPPH free radical scavenging activity compared with ascorbic acid (89.10±0.64%). These results suggest that hydrolysates produced from yellowfin tuna bones with citric acid can be used as a potential natural antioxidant agent in food industry.
Formation of Edible Casings from Hydrolyzed Ovalbumin
(Uva Wellassa University of Sri Lanka, 2018) Rathnayake, R.M.T.S.; Ranasinghe, M.K.; Abeyrathne, E.D.N.S.; Boraluwa, C.
Edible casings are environmental friendly approach that can be applied on food products to control the deterioration due to oxidation or microbial growth, while enhancing the nutritional attributes. Ovalbumin and its hydrolysate exhibit functional properties to a greater extent and can be used to form an edible casing. Thus, the present study was focused to develop an edible casing using hydrolyzed ovalbumin (HOB) and to assess its physical properties. Firstly, already extracted ovalbumin protein was hydrolyzed using 1% pepsin. The HOB solid was dissolved in distilled water (9 g/ 100 mL) and as the plasticizer either levels of glycerin (Gly) at 20, 30, 40 and 50% (w/w of protein) or sorbitol (SB) at 50 and 60% or lactic acid (LA) at 30, 40, 50 and 60% was added. Then, the pH of the solution was adjusted to 11.25±0.10 and heated up to 45°C for 20 min in water bath. The treated solution was tasted into polypropylene covered plates and the films were peeled after 48 hrs at 25±2°C. After peeling, the films were subjected to heat treatment at 85°C for 20 min. The films formed using SB at 50 and 60% had a lower elongation and those of made using LA at 30, 40, 50 and 60% which had a higher brittleness. Films formed with Gly at 20% had higher brittleness while Gly at 40 and 50% had lower elongation compared to the Gly at 30%. The hardness of the prepared films was compared according to the different thicknesses as 0.06, 0.08, 0.10 and 0.12 mm. The thicknesses of 0.06 mm and 0.08 min had higher brittleness and thickness of 0.12 mm had a higher hardness than that of 0.10 mm. In conclusion, Both SB and LA were not suitable in film formation from HOB as plasticizers while the film with 30% Gly and 0.10 mm thickness showed a better film characteristics as an edible casing.
he Effect of Wood Apple Bark Extract (Limonia acidissiina) on Internal and Sensory Attributes of Chicken Eggs Stored under Room Temperature
(Uva Wellassa University of Sri Lanka, 2018) Samaranayake, S.V.A.P.; Aruppala, A.L.Y.H.; Pitawala, H.M.J.; Abeyrathne, E.D.N.S.
Eggs are one of the highly nutritious, low-cost food consumed. Storage under ambient temperature is known to reduce the internal qualities. Wood apple bark extract (Limonia acidissima) is a waxy substance which is available naturally. Coating materials are used to improve the shelf life of eggs. So the objective was to increase the shelf life and preserve sensory qualities of egg using wood apple bark extract as a coating material on eggs. A total of 312 medium sized white eggs from 61-weeks old Hy-line white were purchased from a commercial layer farm. Eggs were individually weighed and arranged under completely randomized design into three different coating treatments as wood apple extract (WA), mineral oil (MO) and non-coated (NC). Each parameters were measured by using 03 replicates. The eggs were stored under room temperature (27 ± 2 °C) for 06 weeks. Weight losses, internal quality parameters such as Haugh unit, albumen and yolk pH values, and microbial analysis for Salmonella of eggs were measured weekly for 06 weeks. Sensory attributes of eggs were measured using 30 untrained panellists (age 23-27). Fourier-transform infrared spectroscopy (FTIR) analysis was done to analyse the structural changes. Weight losses were minimum in MO coated eggs than others (p < 0.05). Haugh unit decreased significantly (p < 005) in NC but in others it was more than 50% till the 04th week. In all treatments, egg albumen and yolk pH increased during the storage (p > 0.05). However, coated eggs reduced the grade from AA to A within 03 weeks. All coated eggs were negative for Salmonella test during the tested period. Colour of the egg yolk did not change due to the coating material. Sensory attributes confirmed that no sensory changes in all treated eggs up to the 03rd week of storage. FTIR analysis confirmed that the Amide-A and Amide-1 bonds of the coated eggs did not change with the time. The present study confirmed that WA is another good replacer for the MO in commercial scale.
Identification of Possible Microbial Contamination Points and Sources in Commercial Tea Blending Process Factory in Kelaniya
(Uva Wellassa University of Sri Lanka, 2018) Liyanawickrmasinghe, T.R.; Dharmarathna, E.K.G.P.O.; Kahandage, K.P.M.; Abeyrathne, E.D.N.S.
Exporting quality deteriorated tea will degrade the brand reputation of “Ceylon tea”. Rejecting tea at point of export will result a loss of international tea market. Objective was to determine the major contamination sources during black tea blending processing in tea blending factory in Kelaniya, Sri Lanka. Nine control points including 06 swab collecting points (packing materials, blending floor, employees' hands, 3 stainless steel equipment used) and 03 tea samples (raw material feeding point, conveyor belt, bag feeding point) have been examined for the enumeration of total aerobic mesophilic bacteria, Coliforms, Escherichia coli, yeast and mould and Salmonella. Microbial count of raw and blended black tea was benchmarked with SLS black tea standards followed by Sri Lanka tea board. Microbial count of raw black tea and blended black tea for total aerobic bacteria and yeast and mould were log 12.2122 ± 0.6232 cfu /g, log 13.3636 ± 0.8751 cfu /g and log 11.9699 ± 0.7404 cfu/g, log 12.0755 ± 0.8751 cfu/g respectively and exceeded the acceptable level according to the Sri Lanka tea board. Employees' hands and blending floor were positive for E.coli and Salmonella tests indicating that high possibility to contaminate Black tea blending process through faecal matter. Control point examination identified, raw material as the primary contamination and personnel hands and blending floor as the secondary contamination sources. High microbial count of blending floor may be due to shoes of visitors and supervisors walking across the floor. In conclusion, there is a requirement to initiate GMP for primary tea processing to select black tea with low initial microbial counts to the plant. Initiation of proper hygiene conditions with sufficient sanitary applications is necessary to eliminate remaining particles from initial blending to minimize cross contaminations.
Identification of the critical control points of a newly established commercial Spray Dried Milk Factory
(Uva Wellassa University of Sri Lanka, 2018) Rajapaksha, L.R.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Food industries maintain number of quality assurance systems to produce safe and quality product. Among them HACCP focus on food production, storage and distribution monitory system for identification and control of associated health hazards. Study was carried out for identification of critical control points (CCPs) for an newly established spray dried milk factory as an initiation to develop the HACCP plan. Preliminary studies were carried out to identify the processing steps and sample collection points. Samples were collected from all processing steps, raw materials to the final finished products. Hazard analysis and the quality of the product were assessed using microbiological (total plate count and coliform) properties and chemical adulterations. According to the preliminary analysis, total plate count (TPC) of the samples taken from raw milk silos was significantly higher than the standard (p<0.05) which range from 6.72±0.65 log cfu while coliform results were positive. Adulterations were also positive at this stage in milk. Samples taken after pasteurization (80°C, 15 seconds) and balance tank (before evaporate) were not contaminated from the coliform, but TPC of pasteurized milk vat 4.99±0.43 log cfu/ml) and balance tank before evaporator (4.84±0.45 log cfu m1-1) was significantly higher than the standard value (p<0.05). However TPC count after the evaporation step (4.08±0.36 log cfu ml-1) and final packed samples (2.68±0.23 log cfu m1-1) were less than the standard value (p>0.05) and coliform were negative in both conditions. According to the analysis; raw milk silos, pasteurized milk vats and the balance tank (before evaporator) were identified as the three CCPs and evaporate milk vats and the fluid bed identified as the critical points. Therefore more attention need to be given to control the three CCPs of the process line of spray dried milk factory.
Production of Biodiesel from Yellowfin Tuna (Thunnus albacares) Fish Skin Wastage
(Uva Wellassa University of Sri Lanka, 2018) Amangilihewa, G.V.; Mahaliyana, A.S.; Kariyawasam, M.G.T.R.; Abeyrathne, E.D.N.S.; Etampawala, T.N.B.
Yellowfin tuna (Thunnus albacares) is one of the major exporting fish species in Sri Lanka. Approximately 50% of the total large pelagic catch in Sri Lanka constitutes tuna-like fish species and usually fillets, steaks, cubes are exported. The rest, which is approximately 1/3 of the harvest is discarded which contain head, skin, tail, viscera and fins. Roughly 5000 tons of fish waste are generated every year in Sri Lanka. Dumping such waste in to the environment can cause various environmental problems. This study was focused to add value to such waste by producing biodiesel as an alternative energy source for petroleum. Tuna fish skins were collected from local processing factory and brought to the laboratory under 4 °C and cut in to small pieces. Fish oil was extracted using different solvents; absolute ethanol, ether, nhexane and 1:1 mixture of ethanol and water using ultra sonication and soxhlet extraction method. Fatty acid profile, energy and the yield was calculated. Accordingly there were no any significant difference in yield of the extracted oil with single solvents used (p > 0.05). But ether was selected as the best solvent (3.24 g±0.61). Among the two methods, Soxhlet method showed the highest oil yield (20 mL/kg of fish skin). Fish oil profile was obtained by using Thin Layer Chromatography (TLC) and Gas Chromatography-Mass Spectroscopy (GC-MS). The extracted oil was used to produce biodiesel using single step transesterification with potassium methoxide. The percent conversion of oil in to biodiesel was 88%. Fourier Transmission Infrared (FTIR) Spectroscopy method was used to characterize the fish oil as well as the biodiesel. The energy capacity of the synthesized biodiesel was measured using a Differential Scanning Calorimeter. All the test results were benchmarked against the commercially available petrochemical based diesel. Accordingly, ether soxhlet separation can be used as a potential biodiesel production from Yellowfin tuna fish skin.
Survey on Consumer Behavior and Egg Quality Parameters in Badulla District among the Consumers Age between 15-44 years
(Uva Wellassa University of Sri Lanka, 2018) Weerakoon, W.M.S.K.B.; Jayawardana, J.M.D.R.; Abeyrathne, E.D.N.S.
Eggs are highly nutritious and perishable food with low price. Quality standards in eggs and egg products are highly concerned in the world. Objective of this research was to assess the consumer behavior and awareness of egg quality among the people age of 15-44 years in Badulla district. Samples were taken using fluid survey web based software. 385 respondents from 15 Divisional Secretaries divisions in Badulla district were interviewed by pre tested questionnaire according to SLS 959:1992. Respondents were categorized in to urban, rural and estate sectors. Hence 72.2% individuals were Buddhist, 20% Hindus, 4.2% Islam. Education level was distributed as; 25.2% Below OIL, 33.2% OIL Qualified, 36.1% AIL Qualified, 4.9% Graduates and 0.5% Post-graduates. 93.8% individuals prefer Chicken eggs while 6.0% prefer quail eggs. 62.9% prefer brown shell eggs and 19.7% prefer white shell eggs. But 17.4% consumers in all age category groups not concerned in color. Majority of the consumers purchase 5-10 eggs per week (50.6%) and only 11.9% purchase 0-5 eggs. Mainstream of the consumers who have purchasing power belong to age category between 24-35 years. 68.1% purchased eggs from retail shops while 11.7%, 11.2% and 9.1% from farms, local houses and super markets, respectively. 30.1% individuals consumed four eggs per week while 27.3% consume three eggs per week and 21% consume five eggs per week per person. 86.8% had some basic knowledge on external defects and 81.1% had knowledge on internal defects. 13.2% and18.9% of consumers had no consciousness regarding internal and external defects, respectively. Urban consumers were more aware on quality than others (p < 0.05). 16.4% consumers use appearance of eggs to identify the level of spoilage while 28.1% shaking, 37.4% by dipping in water and 6.5% by weight loss. Most preferred egg yolk color among the consumers was No 08. In conclusion, consumers in urban area were more concerned on quality standards than the other consumers but identification on defects were high in estate people.

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