Effect of bleaching and defatting treatment of camel skin on the color, structural and interfacial properties of extracted gelatin

Abstract

The effect of defatting and bleaching of camel skin on gel-forming, structural, and interfacial properties of extracted gelatin was studied. Gelatin defatted for 6 h and bleached for 48 h (48BD-6 h) gave the highest yield (28.44%) while gelatin bleached for 24 h (24 BC) gave the highest gel strength (423.3 g). Electrophoretic analysis showed that all gelatin samples had α-chains as the predominant protein type. Fourier transformation infrared (FTIR) spectroscopy showed that all gelatin samples possessed major peaks in the amide region with reduced peak intensity recorded in defatted and bleached samples because of the loss of the triple helix state of the gelatin. X-ray diffraction analysis indicated that all the gelatin samples are basically amorphous with both weak and sharp peaks observed around 7° and broad peaks at ~19–22°. Microstructural analysis revealed highly cross-linked network with less voids in all the gelatin samples which correlated with high gel strength recorded. Colour of the gelatin powder samples were significantly improved by bleaching with an increase in the L ∗ -value and decrease in the a ∗ -value. These results indicates that with bleaching, gelatin molecules were oxidized, resulting in the production of gelatin cross-links, giving gelatin an improved gel strength, colour, and functionality. • Bleached and defatted camel skin produced gelatin with light color and improved interfacial properties. • Bleaching of camel skin produced gelatin with highest gel strength (423 g). • Camel skin gelatin with better functionality could be produced by defatting and bleaching pre-treatment.