Preservative Effect And Mechanism Of The Earthworms Extracts On Meat

As the production of livestock and poultry products in our country sharply increased, how to safely and effectively prolong food freshness has aroused the attention of people. The growth of microbial and the oxidation of fat are the mainly cause of rottenness. There are many kinds of active ingredients, extracted from the earthworm. Given it is significant antibacterial and antioxidation properties, this study used the antibacterial ingredients obtained earthworm preservative (EP), and used EP in the retaining-freshness, exploring it’s effect and mechanism of meat.Method1.Fresh liquid preparation:extracted from earthworm antibacterial antioxidant components using induction, homogenization, sonication, ammonium sulfate precipitation, ultrafiltration method. The antibacterial, antioxidant activity of earthworm extract, explore the impact of the homogenization buffer pH, copper and zinc ion concentration on its activity. Oxford cup method and microdilution method was used to detect the preservation solution (EP) on the inhibition zone, rot pathogenic MIC and MBC, to determine the SOD, CAT, GSH-PX enzyme activity in Nanjing built kit.2. Effective of preservative:by observing the sensory indicators, physical index, chemical index and the total number of colonies of frozen pork, we compared fresh-keeping effect of the different concentration EP and10%propolis.3. Study of preservative mechanism:by testing AKP, ATP enzyme activity of bacteria and microflora on chilled meat, to explore its antibacterial mechanism of meat preservation. By determination protein content and activity of antioxidant enzymes in pork, testing oil AV and POV value, to investigate its oxidation mechanism of meat preservation.Result1.Preservation preparation conditions and activity:when PBS buffer solution PH=7.4, copper ion concentration is0.05mmol/1, zinc ion concentration is0.02mmol/l, EP has strongest antibacterial and antioxidant activity. Test result shows that protein concentration of EP is23.67mg/ml. EP has obvious effect of antibacterial and sterilizing on Staphylococcus aureus, Escherichia coli, Lactobacillus and Bacillus subtilis. EP has no sterilizing effect on pseudomonas aeruginosa and no antibacterial and sterilizing effect on yeast. The SOD specific activity of EP is2475.14U/mg, CAT specific activity is676.46U/mg, GSH-PX specific activity is3368.62U/mg.2.Preservation effect:EP can delay the official index, cooking loss, SAP turnover rate and PH change on chilled meat, it can reduce globin precipitation, TVB-N, TBA quantitative values rise, have better preservation effect. EP added concentration between5%～30%the effect is best, the shelf life of chilled meat with15%EP can be extended to20days or so.3.Mechanism of preservation:EP can through reduce the bacteria’s AKP, ATP enzyme activity to inhibit bacteria growth, through inhibit dominate bacteria growth to reduce total bacteria number witch in meat; EP can retard reduction of meat protein content and antioxidant enzyme activity, inhibiting lipid AV and POV value increases, thereby delay protein and axunge rancidity in the meat.Conclusion:EP has significant antibacterial effect on many kinds of spoilage bacteria, and contains antioxidant enzymes activity than higher, can obviously prolong the shelf life of chilled meat. EP main delay meat spoilage from antibacterial, antioxidant two, can reduce the bacteria AKP, ATP enzyme activity inhibition of bacterial growth and reproduction; through the protection of fleshy antioxidase activity, reduce lipid oxidation degeneration to antioxidant effect.