Study Of Effects Of Compound Preservatives And Modified Atmosphere Packing Cooperative Processing On The Preservation Of Spiced Beef

As a traditional high-grade meat product, spiced beef has a long history, rich nutrition,and delicious taste by the vast number of consumers. But spiced beef with high nutrition was easy to putrefy, resulted that the sale radius was small, and the storage period is short, which restricting spiced beef industrialized production. Second sterilization with vacuum packaging and radiation sterilization could extend the shelf life but they had bad effect on flavor of spiced beef.cold chain transportation required much money. In order to maintain the flavor of spiced beef and prolong the shelf life, new and suitable preservation technology need to be solved.In this paper, we studied the effects on preservation of spiced beef with modified atmosphere packaging combineing preservative. First, selecting six kinds of different preservatives, studied respectively on the test of bacteriostatic with Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Yeast. In terms of economic and efficient we selected three kinds of preservatives on the basis of validation test for three factors and three levels orthogonal test, and got the optimal level combination. And we studied the thermal stability of the preservatives. At last, combineing with the preservatives with modified atmosphere packaging processing, we studid the effects of preservatives on the preservation of spiced beef and detected the residues of preservatives. The research results show that:(1)The single factor experimentshowedthat natural poly lysine of nisin, natamycin and 8ε-poly lysine had better effect on antibacterial than chemical preservatives of sodium nitrite and potassium sorbate. On the whole the rate of inhibitory increased with the adding concentration increased. The rate of inhibitory of 0.20g·kg-1 nisin antibacterial against Bacillus cereus and Staphylococcus aureus was 100%.0.06g·kg-1 natamycin against Yeast was 100%, 0.10g·kg-1 poly lysine against bacteria was 100% and low against Yeast,0.20g·kg-1 sodium dehydroacetate was 100% against yeast, others were low. In consideration of economy and efficiency, we selected of ε-polylysine, sodium dehydroacetatc and potassium sorbate to orthogonaltest. Orthogonal test showed that the main influence factors on inhibition of bacteria was ε-polylysine, main factors affecting the inhibition on Yeast was sodium dehydroacetate. Combineing the inhibition effect on bacteria and Yeast, optimal combination was 0.10g·kg-1 poly-L-lysine, 0.20g·kg-1 sodium dehydroacetate, 0.015g·kg-1 potassium sorbate.(2) Study of thermal stability shows that three kinds of preservatives were steady on thermal. It did not affect the activity of three preservatives for 30min in 60 degree, 70 degree,80 degree,90 degree and 100 degree water bath. The temperature of sauced beef on processing project was not higher than 100℃ and the antibacterial activity would not be effected adding in later of cooking processing.(3) During the period of storage, according to the national standard of total number of colonies 4.91og (cfu·g-1), the shelf life of preservatives combined with modified atmosphere packaging group were 100% and 50% longer than vacuum group and modified atmosphere packaging group. TBARS value and TVB-N value of three treatment had no difference on 8th day in storage; TBARS value of preservatives combined with modified atmosphere packaging group were 22%、9% lower than vacuum group and modified atmosphere packaging group on 8th day in storage,and TVB-N value were 36%、 3%. The electronic nose and sensory analysis showed that the preservatives combined with modified atmosphere packaging could maintain flavor of spiced beef better.It showed that preservatives combined with modified atmosphere packaging cooperative processing could prolong the shelf life of spiced beef and maintain its flavor better.