Preparation Of Antibacterial Peptides From Milk And Its Effect On The Preservation Of Raw Meat

In recent years, the research of active peptides from milk has become a new frontier of science in dairy nutrition, and the research of antimicrobial peptides derived from milk protein has become a hot research topic in the field of dairy products. Meat is an indispensable food part of people’s daily life, and fresh meat preservation technology has been a perplexing problem for people. At present, the most convenient and economical fresh keeping technology is the combination of low temperature and fresh keeping agents. Natural preservative has become a focus of research and development of chilled meat preservative because of its natural, rich, safe, efficient, wide antimicrobial spectrum and so on. At this stage, a variety of methods used in the preservation of meat, however, the combination of antimicrobial peptides with natural preservative and application to the preservation of meat,rarely reported.This paper mainly studies the preparation and purification of the best antibacterial peptides from milk, and the application of compound with natural preservative in chilled meat preservation. The main conclusions are as follows:(1) with the diameter of inhibition zone as index, bovine casein and feta cheese protein under the optimal enzyme solution conditions of the papain, pepsin and a combination of both enzymes were compared their enzymolysis liquid antibacterial activity. The results show that the antibacterial effect of the goat cheese protein pepsin enzyme inhibitory effect of solution is the best.(2) Using the ethanol precipitation protein method to remove some of the proteins in the enzymatic hydrolysate to achieve the purpose of separating and purifying the enzymatic hydrolysate. Determine the optimal process combination for the ethanol concentration is 85%,precipitation time is 20 min, the volume ratio of ethanol is 1:2, the precipitation temperature is 30 ℃. The test results show that ethanol precipitated enzyme has certain feasibility in the liquid part of the protein solution, but the effect on improving the active peptide concentration and antibacterial properties is not ideal.Macroporous adsorption resin was used to separate and purify the enzymatic hydrolysate,the test results showed that the LS-106 macroporous adsorption resin after separation andpurification of the antimicrobial effect of the enzyme solution is better than the LS-105 type.(3) Studied the antibacterial effect of antibacterial peptides and natural preservative, two kinds of compound biological preservative were successfully developed, compound preservative 1#is composed of antimicrobial peptides(14.25g/L), natamycin(2.50g/L), apple polyphenols(4.00g/L) and chitosan(2.28g/L), compound preservative 2# is composed of antibacterial peptide(6.55g/L), epsilon polylysine(1.00g/L), tea polyphenols(2.50g/L),pullulan acid(2.00g/L).(4) The effect of compound preservative on the preservation of chilled pork and lamb was studied. The results showed that preservative agent both1# and 2# have extend the role of pork and mutton preservation period, preservative agent 1#can effectively control the TVB-N and TBARS value, inhibit spoilage bacterium growth and reproduction, and improve the sensory evaluation scores, compared with the control group can prolong the preservation period of pork and mutton 4-6d; preservative agent 2#can prolong the preservation period of pork and mutton 3-5d. Biological preservative has the advantages of simple manufacture technology, safe and convenient, has very high value in popularization and application.