Study On The Effect Of Pigskin Gelatin Enzymatic Preparations On Bone Density

The resource of pigskin gelatin is very abundant in China, and pigskin gelatin contains 18 amino acids. Because of its various healthcare functions and none fat and cholesterol, pigskin gelatin is favored by more and more people. The results of national nutrition survey showed that: calcium intake was insufficient in Chinese residents, which would seriously affect the national physique. This experiment explored the hydrolysis process of pigskin gelatin and the chelating process of pigskin collagen peptides and calcium, aimed to prepare a collagen polypeptide calcium supplement that could promote the formation of collagen.The pigskin gelatin was selected as raw material, and chose five typical kinds of protease to hydrolyze it under their optimal conditions. Hydroxyproline from enzymatic hydrolysate was as the evaluation index. The main results were as follows: The content of hydroxyproline was the highest in the SG protease, then GW protease, neutral protease, alkaline protease and papain after hydrolysis. Therefore, SG protease was selected to continue the following experiment. Using Hydroxyproline content as evaluation indexes, single factor and orthogonal experiments were conducted. The results showed that: hydroxyproline were highest when the p H 3.0, hydrolysis temperature 45℃, enzyme dosage 0.05g/g, hydrolysis time 4.5h.Using collagen polypeptide from pigskin gelatin and glucose as raw material, and polypeptide calcium chelating rate was as the index. Through Plackett-Buiman(PB) analysis and Center Combination, collagen polypeptide / water ratio of material to liquid, collagen polypeptide / calcium gluconate mass ratio, p H, reaction temperature, reaction time, stirring speed, stirring time and other factors were investigated on the impact of pigskin collagen peptide chelating rate. The best optimization was water ratio of material to liquid 1.5:100, the reaction temperature 60℃, stirring speed 30r/min, stirring time 20 min, the collagen polypeptide calcium carbonate / grape quality rate 5.5:1, p H 6.0, reaction time 130 min. Under these conditions, collagen peptide chelating rate reached 78.3%. X diffraction was used to test pigskin collagen polypeptide and pigskin collagen peptide chelating calcium. The results showed that a new chelate was formed by the pigskin collagen polypeptide and calcium.The influence of pigskin collagen peptide chelating calcium on bone mineral density in SD rats was studied. The weaning female SD rats of 4 weeks old were randomly divided into 7 groups, fed with low calcium based diets, and distilled water, different doses of collagen peptide chelating calcium and calcium carbonate. Three days calcium metabolism tests were done after gastric lavage 4 weeks to calculate the calcium apparent absorption rate. During the breeding process, weight and height of the rats from each group were measured, and its growth rate was calculated. Killing rats after 3 months, rat femur was stripped, indexes of rat femur length, dry weight, bone mineral density and bone calcium content of femur were tested, surface changes of rats were observed by scanning electron microscope. The results showed as follows: the increasing rate of body weight, length, quality, femoral bone mineral density and bone calcium content of 20 times dose peptide chelated calcium group was significantly higher than the control group. The increasing rate of body weight and femoral bone mineral density of 10 times dose peptide chelated calcium group was significantly higher than the control group. The increasing rate of body weight, femur bone mineral density and bone calcium content of 20 times dose of peptide chelated calcium group was significantly higher than that of the corresponding dose of calcium carbonate group. The increasing rate of body weight and bone mineral density of 10 times dose of peptide chelated calcium group was significantly higher than that of the corresponding dose of calcium carbonate group. calcium apparent absorption rate was higher than the corresponding dose of calcium carbonate group by 10, 20 times the dose of peptide chelated calcium, which was significant different. The rat femoral surface scanning electron microscopy revealed that 20 times dose of peptide chelated calcium rats femoral osteoblasts were active and bone mineral density was increased.