Evaluation On Anti-fatigue Action Of Dairy Products Rich Of Opioid Peptides

Anti-fatigue peptide not only has reasonable nutritional value but also has function of improving body function,relieving fatigue,improving work efficiency.In the previous study,pepsin was used to hydrolyze casein preparing opioid peptide,initially identified the preparation conditions,and got the purity of 93.765% of opioid peptides.And initially animal experiments was conducted to determine the anti-fatigue effect of opioid peptides with anti-fatigue effect.In this study,animal experiments were taken to optimize the conditions for pepsin to hydrolysis casein preparing opioid peptide and to evaluate the anti-fatigue function of casein hydrolysates.And then debitterized the hydrolyzate,added the hydrolyzate to the milk powder to prepare dairy products with anti-fatigue effect.In this paper,pepsin was used to hydrolyze the casein in order to prepare antifatigue peptides.With loaded swimming time as an evaluation index,the condition of hydrolysis casein with pepsin was optimized,that including substrate concentration,the ratio of enzyme to substrate,pH value and temperature,in order to obtain the best casein hydrolyzate for anti-fatigue function.And all the casein hydrolyzates were analyzed with the capillary electrophoresis.The results showed that the casein hydrolysate which was prepared under the conditions of that ratio of enzyme to substrate is 1:30,substrate concentration is 5%,pH valule is2.5,temperature is 43?,it can significantly prolong mice loaded swimming time compared with other hydrolysis products feeding groups(P<0.05),ascertaining the optimized hydrolysis conditions of the optimal anti-fatigue effect.Following the requiments of the book-Technical Standards for Testing & Assessment of Health Food(2003),we investigate the anti-fatigue effect of casein hydrolysates.The healthy male mice were primed by intragastric administration with hydrolyzates for 28 days and were determinated the fatigue index such as forced swimming time,blood urea nitrogen(BUN),blood lactate(BLA)and liver glycogen(LG)to evaluate the anti-fatigue function of hydrolysates.The results show that casein hydrolysates can enhance the swimming time of mice,and the results was positive;it can reduce blood urea nitrogen level,lower blood lactate level and increase glycogen level,and could improve the anti-fatigue endurance of body.Added the cyclodextrin to Hydrolyzate,the ratio is 5:1.Then let them oscillating react at a temperature of 40 ? for 30 min,and ultimately debittering value is 1.Sensory evaluation was taken to evaluate the designing formula milk powder and finally got the optimum formula.After hydrolysates debittering,the formula powder is added 4.2g hydrolysates and 17 g cyclodextrin to per 100 g milk powder.Then through animal experiments,the anti-fatigue effects of formula milk powder weredetected.The results show that compared with the control group,the weight of the low dosage and high dosage group has no significant differences(P<0.05),indicating that under the experimental conditions,casein hydrolysates do not affect mouse growth.With the negative control group(CG),the force swimming time of the low and high dosage groups has significant differences.It showed that the mice swimming endurance can be improved,the mice anti-fatigue ability can be enhanced.Compared with the control group,BUN level and BLA level in the low and high dosage group,was significantly lower;the LG level was significantly different only it the low dosage group,while the high dosage group is not statistically significant.The results show that: the milk powder adding casein hydrolysates can prolong swimming time of mice,reduce the blood urea nitrogen level,increase hepatic glycogen reserves,delay the generationof fatigue and reduce lactic acid production.