Study On The Enzymolysis Characteristic And Product Development Of Pigskin

Pigskin gelatin is a kind of health, beauty and leisure food with low fat, low calorie and high collagen. With pigskin as materials, traditional pigskin gelatin made at high temperature has many defects such as low gel viscosity, low fusing point, poor water binding capacity and water effusion after storage, which not only affect the taste and flavor, but also damage the functional collagen. Based on the gel and functional properties, the product was developed. With the hydroxyproline content as the index, low temperature enzymolysis method was used to optimize traditional pigskin gelatin manufacturing technique. The advantages including high viscosity, high strength and high fusing point of konjac glucomannan were utilized to solve the problems existing in the traditional pigskin gelatin. The functional properties of enzymolysis pigskin gelatin were studied. The healthy food product was made combined with the characteristics of konjac glucomannan.With the yield of hydroxyproline as index, enzymolysis time, hydrolysis temperature, enzyme dosage and material-liquid ratio were studied. In the basis of single factor experiment, response surface experiment was designed to optimize the preparation conditions of pigskin gelatin. The critical control point was constant temperature enzymolysis. The results showed that the enzyme dosage was 0.25%, material-liquid ratio was 1:2, enzymolysis time was 1.65 h and enzymolysis temperature was 41℃. Under the optimum process conditions, the hydroxyproline content was 4.8495%.With pigskin gelatin as the research subject, the functional properties including hydroscopicity and oil absorbency, the scavenging effects of superoxide anion free radical, hydroxyl radical and hydrogen peroxide, and DNA damage protection effect were studied.The results showed that the hydroscopicity was 1.172g/g and oil absorbency was 2.074 ml/g. The IC₅₀ values of superoxide anion free radical, hydroxyl radical and hydrogen peroxide, and DNA damage protection effect were 20.19, 6.36, 0.65 and 1.86 mg/ml, respectively. Compared with the traditional process of the pigskin gelatin, antioxidant activities were high.Pigskin gelatin with different amount of konjac glucomannan was selected as research subject. The moisture migration distribution by low field nuclear magnetic resonance, gel strength by texture analyzer and microstructure by scanning electron microscopy were studied. The results showed that, The moisture migration distribution and migration changed when added moderate amount of konjac glucomannan and the hydroscopicity increased. In a certain range, with increasing of the content of konjac glucomannan, the relaxation peak of free water moved to the left. When the adding amount of konjac glucomannan was 0.5%-0.7%, the relaxation time was very close between pigskin gelatin and fresh meat.It has good sense and state without suction phenomenon. Gel strength of pigskin gelatin has increased with the increasing of konjac glucomannan content. It decreased when reached a certain value. When the addition amount of konjac glucomannan was 0.5%, the gel strength was the largest. With the increasing of konjac glucomannan content, pore structure on the surface of the pigskin gelatin became smaller.It indicated that konjac glucomannan holes on the surface of pigskin gelatin had filling effect. When the addition amount was 0.5%, the holes on the surface structure almost disappeared.In a certain range, with the increasing of the konjac glucomannan, free water relaxation peak moved to the left.When konjac glucomannan addition amount was0.5%, the moisture distribution and relaxation time was closed to the average moisture content in fresh meat.The gel strength of pigskin gelatin increased with the increasing of konjac glucomannan content. When the addition amount of konjac glucomannan was 0.5%, the gel strength was the largest.With the increasing of konjac glucomannan content, pore structure on the surface of the pigskin gelatin became smaller. When the addition amount was 0.5%, the holes on the surface almost disappeared.Pigskin gelatin enzymatic hydrolysate and konjac glucomannan were used as the main raw materials. The energy value was used as an index to develop low calorie health food. On the basis of single factor experiment, the orthogonal experiment was design to optimize the preparation procedure of low calorie health food. The collagen peptide was 25%. The carrageenan was 3.5%.The konjac gum pectin was 1%. The xylitol was 4%.The indexs of protein, energy, fat, amino acids and other nutritional index were analyzed. The nutrition labeling was made and compared with ordinary fudge in the market. The product had low quantity of heat,combined with beauty, antioxidant effect and the satiety characteristics of konjac glucomannan. It provided reference datas for further development of diet food.