Research On Processing Surimi Gel Food Using Tilapia,Channel Catifsh And Their By-products

The meat of freshwater fish is delicious and nutritious. Surimi products is one ofthe trend of development of the aquatic products processing. China have rich fisheryresources, the annual production of freshwater fish such as tilapia and channel catfishfish is huge, but the processing rate is low, and by-products has not been fully utilized.In this study, Surimi gel food using Tilapia, Channel Catfish and their by-products wereproduced, and the shelf life of the product was predicted.Effects of modified starch, soy protein, fat and glutaminase on Tilapia andChannel Catfish surimi gel were studied，and the results show that the effect ofmodified starch and transglutaminase on product quality were better. The productformulas and processes were optimized by single factor and orthogonal test：Above all，fish meat were rinsed three times in cold water (5℃), and addition0.5%NaCl last time,each time5min. Processing in lower temperature (no more than10℃). Two-stagemethod was chosen when surimi gel were heated. Best formula of Tilapia surimi is4%of the soy protein, modified starch5%, TG0.6%, fat4%，and best formula of ChannelCatfish surimi is3%of the soy protein, modified starch7%, TG0.8%,4%fat.Extracting collagen of skin with acid extraction from Tilapia and Channel Catfishwas studied, and the effects of solid-liquid ratio，acetic acid concentration, extractiontime and extraction temperature on extraction rate of collagen were researched. Inexperimental, the optimal conditions for higher extraction rate of skin collagen were asolid-liquid ratio of1／15, acetic acid concentration of0.5M, extraction time of24hand extraction temperature of20℃. In these condition, Extraction rate of Tilapia andChannel Catfish sample were61.2%and45.36%. Collagen casings was produced fromskin collagen which have better hardness, toughness and permeability.In order to manufacture calcium-rich fish sausages, the effect of fish bone mealaddition on fish sausage quality was studied. Color and textural properties as well assensory evaluation of fish sausages were determined. The results showed that as thebone meal addition increased, b*value increased, w value decreased significantly while adding2%. An obvious increasing tendency in hardness and chewiness wereobserved at high levels of bone meal addition, but cohesiveness has no changesignificantly. With the increase of bone meal addition, the section rough of productbecame rough, and have strongly grainy feeling when chew it. It is difficult to beaccepted when bone meal was3%. Generally,1.5%bone meal in fish sausage was moreeffective in terms of color，textural properties and sensory evaluation.The shelf life of Channel Catfish surimi gel were predicted. The results showedthat product shelf life of surimi gel add0.1%nisin and0.1%sodium erythorbate were21.7days in room temperature (25℃) and172days in low temperature (4℃).