Preparation And Research On Anti-fatigue Effects On Active Peptides From Enzymatically Hydrolyzed Male Silkmoth Protein

Male moth is nourishing physical share and there are number of related health products in the market. Anti-fatigue effect is also confirmed in clinical practice, more research is currently focused on the male hormone, ecdysone and other active ingredients.Because of the cause of an allergy, male silkworm moth protein content as high as 40% is rarely used in food, resulting in a waste of resources, but its use in the field can be broadened by enzyme technology. In male silk moth as raw material, prepared by enzymatic peptides to mining natural, safe and effective anti-fatigue factor and product development capabilities, thus achieving comprehensive utilization of resources and value promotion of the sericulture byproducts.1. Establishing effective reasonable enzymatic hydrolysis process so as to the development of health care products with special function activity. The experiment to silkworm moth powder as raw material, took p H, temperature, time, ratio of enzyme, and solid-liquid ratio, dosage of enzyme factors as single factors, and regarded the degree of hydrolysis of male silkworm moth protease solution and peptide yield as indexes to control the experiment, the best conditions are p H10, the temperature was 50 ℃, time for 120 min,substrate concentration of 7.5%, double enzyme mixture ratio was 1:2, the enzyme activity was 5000U/g. Subsequently, using the Box-Benhnken center combination experimental design method for digestion conditions were optimized, building enzyme solution efficiency of regression model based on p H, temperature, time, and solid-liquid ratio of four factors. After the Design-Expert software for data regression analysis and combined with the results of the test, we confirmed the optimized enzymatic hydrolysis conditions:p H 9.5, temperature of 55℃, time of 130 min, material liquid ratio was 70%. Under the condition of the optimized process, validation of the results were 27.32% degree of hydrolysis and 50.43% of the peptide yield,the integrated value up to 40.47%. Establish regression model could better predict enzymolysis effect and had certain guiding significance to the research on the practical production.2. The detection on antioxidant activity and its stability of male silkworm polypeptide.At first, to determine the molecular weight distribution on male silkworm protein and its hydrolysate. Secondly, Male silkmoth hydrolysates(MSH) were isolated into five fractions:MSH-I(MW>30k Da), MSH-II(10–30k Da), MSH-III(5–10k Da), MSH-IV(3–5k Da), and MSH-V(<3k Da) by ultrafiltration. The antioxidant activity, molecular weight distribution and amino acid contents of each fraction were evaluated. There were significant statistical differences between the ultrafiltered fractions, The antioxidant capacity of MSH-I as a major antioxidant component was 1950 μmol/g in the oxygen radical absorbance capacityassay and 275 μmol/g in the DPPH free radical scavenging method. Then the effects of Na Cl, temperature, p H, light intensity and a simulated gastro-intestinal digestion were assessed to determine the stability of the crude peptides, the result shows moth antioxidant peptides is suitable in the low salt at room temperature, appropriate light and natural p H conditions, and has better resistance to digestion stability in processing and preservation.3. Study on the male silkworm polypeptide on mice anti-fatigue effect and the changes of mechanism. Animal experimental mice were divided into five groups,respectively, including the blank control group, experimental control group, low dose group, middle dose group and high dose group. After feeding time period of one month, the experimental group was treated with sleep deprivation, and then carried on the test of load swimming endurance and physiological and biochemical indexes. The results showed that the swimming time of blank group is higher than control groups, however, there was a significant difference between the medium dose and other experimental groups. The physiological and biochemical indexes showed that the dose group had better antioxidant capacity and the energy metabolism intensity index was also better. In comparison with muscle tissue sections, the mouse muscle tissue of the medium dose group was better than other groups.