Browsing by Author "Manjula, U.D.P."

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    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.
  • No Thumbnail Available
    Item
    Development of Fish Glue using Skin of Yellow fin tuna (Thunnus albacares) and Mahi-mahi (Coryphaenidae hippurus) and Characterization of glue Properties
    (Uva Wellassa University of Sri Lanka, 2012) Manjula, U.D.P.; Jayamanne, S.C.; Nadeeka, T; Malawige, M
    Fish glue is made out of fish skin and is a special type of glue which differs from other animal glue due to their specific glue properties. It remains as a liquid in room temperature and has a higher open time, and very sticky (Shepherd, 2009). Fish glue is usually made from head bones, skin and fins of the cold water marine fish. Characteristics of the final glue product depend on the raw material selected (Norland„ 1990). Recognition of the limited biological resources and increasing environmental pollution has emphasized the value-addition using under-utilized fish and the by-products from the fish industry (Geurard ei at. 2002). Dorsal skin of Yellow fin tuna (Thtuuiius albacares) is removed during tuna processing and can be used as a source of fish collagen. The main objective of this study was to find out the best quality fish glue using fish skin of the yellow fin cuna and Mahi-mahi (Cor)›phaenidae hippurus), and to identify the best and cheapest processing method For extraction of fish glue from yellow fin tuna and Mahi-mahi fish skin.
  • No Thumbnail Available
    Item
    Development of Fish Glue Using Skin of Yellow Fin Tuna (Thunnus Albacores) and Mahi-Mahi (Coryphaenidae Hippurus) and Characterization of Fish Glue Properties
    (Uva Wellassa University of Sri Lanka, 2012) Manjula, U.D.P.
    Fish glue is water soluble hydrophilic colloidal proteins derived by controlled hydrolyzation of water insoluble collagen. The yellow fin tuna and Mahi-mahi fish glue was prepared by extracting gelatin from fresh and frozen skin by alkaline pretreatment followed by acid extraction method. Different acid and alkaline concentrations (0.1 %, 0.2 % and 0.4 %) and soaking time (18 hours, 24 hours for YFT and 1 hour, 3 hours for MM fish skin) were used for different fish glue type extraction. The proximate composition of the YFT and. MM fish skin were 39.1% moisture, 60.95% crude protein, 10.51% crude fat and 2.4% crude ash and 33.8% moisture, 46.73% crude protein, 5.83% crude fat and 6.7% crude ash respectively. The physical and chemical properties of the fish glue such as proximate composition, open time, Bonding power, pH, color, and yield were determined separately based on the changes in concentration and soaking time. The best acid and alkali concentration and soaking time for YFT skin was 0.2 %, 24 hours soaking time. While for MM skin it was o,4 %, 3 hours soaking time at 60 °C. The variance between glue sample of YFT and MM due to changes of acid and base concentration and soaking time did not show any significant variance except open time (p<0.5).The YFT and MM glue works better on wood tacking and glass tacking purposes.