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Title:	Optimization of gelatin extraction and physico-chemical characterization of gelatin extracted from skin and bone of catfish (Clarias Gariepinus)
Authors:	Venous Sanaei Ardekani (P52565)
Supervisor:	Abdul Salam Babji, Prof. Dr.
Keywords:	Gelatin Catfishes
Issue Date:	6-Sep-2012
Description:	Gelatin processing from catfish (Clarias Gariepinus) skin and bone were optimized by response surface methodology (RSM) involving a Central Composite Design (CCD). RSM with 3-factors, 5-levels CCD was conducted for skin gelatin optimization whereby RSM involved 4-factors, 5-levels CCD was adopted for bone gelatin optimization. In optimization of catfish skin gelatin the dependent variable was percentage of hydroxyproline recovery and independent variables were Sodium hydroxide (NaOH) concentration, acetic acid concentration for the pre-treatment and extraction temperature for the hot-water extraction. Predicted maximum yields of 65.32% for gelatin processing of catfish skin were obtained under the conditions of pre-treatment with 13 N NaOH, 0.09 N acetic acid and hot-water extraction at 64.92 °C. In optimization of catfish bone gelatin the dependent variable was percentage of hydroxyproline recovery and independent variables were concentration of HCl, treatment time for the pre-treatment and extraction time and temperature for the hot-water extraction. Predicted maximum yields of 61.81% for gelatin processing of catfish bone were obtained under the conditions of pre-treatment with 3.35% HCl for 14.5 h and hot-water extraction at 67.23 °C for 5.2 h. The physico-chemical properties of catfish skin and bone gelatins were also determined. Physico-chemical properties monitored in this study included gel strength, viscosity, viscoelastic properties, texture profile analysis (TPA), pH, isoionic point, colour, turbidity, microscopic examination by using scanning electron microscopy (SEM), amino acid composition, molecular weight distribution by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and estimating the secondary structure of protein by using fourier transform infrared spectroscopy (FTIR). Gel strength of catfish skin and bone gelatins gel were 286.71 g and 230.25 g, respectively as compared to bovine gelatin (300 g). At 60°C, catfish skin and bone gelatins exhibited greater viscosity (3.45mPa.s and 4.64mPa.s, respectively) than bovine gelatin (3.17mPa.s). The viscoelastic properties of catfish skin gelatin and bovine gelatin were higher than catfish bone gelatin. Gelling and melting point of catfish skin gelatin (21.8, 28.2°C) and bovine gelatin (20.6, 27.5°C) were higher than catfish bone gelatin (17.8, 25.1°C). To characterize differences in molecular weight, gelatin preparations from catfish skins and bones and bovine, catfish skin and bone gelatins found to contain a notable amount of α-components but there was less content of α-components, also catfish bone gelatin showed considerable amount of low molecular weight components. The isoionic points of gelatins extracted of catfish skin (9.06) and bone (8.71) were higher than bovine gelatin (5.35). Catfish skin and bone gelatin were snowy-white. Microscopic examination of catfish bone gelatin gel showed a few more voids than the skin gelatin gel. A number of interwoven porous protein fibers were observed which is typical of gelatin and other hydrocolloids, making them resemble a sponge-like matrix. FTIR spectra of catfish skin and bone gelatins exhibited major adsorption bands at 3309–3310cm-1 (amide A), 2926-2929cm-1 (amide B), 1644-1645cm-1 (amide I), 1550-1563cm-1 (amide II) and 1240-1241cm-1 (amide III). The results of this experiment showed the potential of catfish skin and bone especially skin as raw material for gelatin production.,Tesis ini tiada perakuan deklarasi pelajar
Pages:	127
Call Number:	QP552.G4A734 2012 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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