Study On Enzymatic Hydrolysis, Nutritional Analysis And Functional Assessment Of Chinese Brown Frog (Rana Chensinensis) Meat

Chinese brown frog (Rana Chensinensis) distributes in Changbai mountainous, the northeastern China and is classified as. Anura, Ranidae, Rana. It is famous for its oviducts locally called"Ha Shi Ma"oil used in Tranditional Chinese Medicine. Untill today, the study on Chinese brown frogs mostly focus on the oviducts of female frogs. And the frog meat is only used as feedstuff, which resulting in serious waste of resources and loss of nutrition, so made the frog products high cost and low profit. The frog meat exhibited high nutritional value with its low content of fat and high content of protein. It is possible that frog meat is developed into a senior nutrition and health food.In the present study, the nutritional content of meat of Chinese brown frogs collected in Xinbin and Benxi, the northeastern China, and a nutritional assessment were determined. The results show that the protein, fat, ash, moisture content in Chinese brown frogs meat are similar with that in bullfrog meat. EAA/TAA value and EAA/NTAA value are in line with FAO/WHO (1973) developed the standard model. Leucine, lysine and methionine content were higher than those in Bullfrog. Glutamic acid and Asparagic acid were rich in Chinese brown frogs, so are the mineral elements P, Ca, Fe content.We hydrolyzed the Chinese brown frog meat into polypeptides by using various of enzyme in this study. Firstly, the hydrolysis degree produced by six of proteinase were determined.The animal protein enzyme showed the best hydrolysis effect. Then, in order to optimize the process of the animal protein enzyme hydrolysis, the five factors 3 levels L27 (313) orthogonal test was carried out to establish the optimum conditions of water, pH, the amount of enzyme, temperature and time. The results indicated that the hydrolysis degree was the highest when 10g of meat was mixed with 30ml of water and 0.10g hydrolase, and hydrolyzed at the temperature of 60℃for 3h. The hydrolysis degree increased with the hydrolysis time from 81% at 1 hour to 94.94% at the end of hydrolysis. The hydrolysate of Chinese brown frog meat was gradually short from the molecular weight of more than 30 kD to less than 3kD at the end of the hydrolysis.In this paper, the aminal test about the anti-fatigue activity and the promotion of growth and development of the hydrolysates of chinese brown frog meat was carried out according to the methods issued by the Health Ministry in 2003. The results showed that the loaded swimming time in the mice filled by the hydrolysate of frog meat was significantly extend, and the content of lactic acid in blood and urea nitrogen content in serum decreased. This facts that the hydrolysate of frog meat sped up the metabolism of the muscles of lactic acid and reduced the forming of serum urea nitrogen suggested that'the hydrolysate of frog meat has anti-fatigu activity. The weight of rats filled with the hydrolysate of frog meat increased significantly compared with that of control rats, and the bone density, the bone calcium content was significantly improved. This results indicated that the hydrolysate of Chinese brown frog meat could promote the growth and development and increase bone density of rats. We expected to provides basic data for the processing and comprehensive utilization of the Chinese brown frog meat.