| China was abundant in fresh water fish. The production of fresh water product was 21.3397 million tons in 2004, of which silver carp, bighead, grass carp account for sixty percent. However, as a result of their poorer quality and less processing rate, silver carp, bighead, grass carp was not put to good use. Effect of materials, other ingredients, and manufacting process on gel properties, water holding capacity, color and sensory quality of composite gel product was studied and surimi-pork composite gel product of good qulity was developed basing on analyzing basic composition, amino acid composition and function properties of pork and surimi. The gel mechanism was primarily discussed through the determination of myofibril protein denaturation temperature and dynamic rheological properties. The main results were summarized as follows:1. Some differences of basic composition, amino acid composition and function properties were found between sivler carp surimi and pork. Solid content of silver carp surimi was lower than pork, while salt soluble protein, emulsifying properties, water holding capacity and cohensiveness was higher. Amino acid content of pork was higher than silver carp surimi, especially abundant in hydrophobic amino acids, which are good to form gel matrix.2. Effect of materials and ingredients on the quality of composite gel product was studied. Gel strength increased first and then decreased with the increasing of the amount for pig lean meat and redness of the product was raised. Gel strength decreased and whiteness was improved significantly after adding pig fat. The more water was added, the lower gel strength was and the more water lost. Liquid egg white could increased rigidity and elasticity of composite gel product, soy protein could increased gel strength of product and water holding capacity was improved. However, overmuch soy protein added might induced high rigidity and low elasticity. Sodium pyro-phosphate, sodium tripoly-phosphate and sodium hexametaphasphate improved gel properties of composite gel product to different degree. After surimi-pork mixture chopped with salt, Microtrans-glutaminase promoted the crosslink of surimi and pork and enhanced gel strength of product significantly. The optimum formulation was: surimi 70, pork paste30, pig fat 6, water 30, liquid egg white 16, soy protein 3, composite phosphate (pyro-phosphate: sodium tripoly-phosphate: sodium hexametaphasphate = 4:2:3) 0.45, and transglutanminase 0.5.3. Effect of manufacturing process such as washing, chopping, pig fat and heat treatment on quality of composite gel product was studied. Breaking force, deformation, gel strength was greatly increased through washing surimi with tap water and pork with sodium carbonate solution (pH11). The quality of the product can be improved obviously by stirring slowly for two minutes and depositing for five minutes during washing. Frozen pig fat and other ingredient would be add after chopping with salt for 60see. Gel properties of composite product heated by two step heating(40℃, 50min; 90℃, 30min) were significantly better than one step heating (90℃, 30min). The quality of composite gel product heated by high pressure was worse than heated by two step heating.4. The gel mechanism of composite gel product was primarily discussed. The denaturation temperature and dynamic rheological properties of fish and pork myofibril proteins were determined. No fish or pork myofibril protein denaturation peak was not found in the curve for the mixture of fish and pork Myofibril protein with the riatio 7:3. When adding starch or fat, G' of myofibril protein mixture raised sharply after 65℃. Surimi and pork myofibril protein might interact with each other and formed composite gel matrix which was filled with fat and starch gel during heating.
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