Preservation Effect Of Natural Spice Extracts On Chilled Pork

Chilled pork is the main development direction of fresh meat production and consumption in the future. However, chilled meat spoilage caused by the growth of microorganisms has been the primary problem meat producers concern during production, transportation, storage and selling, and the research of natural antistaling agent is of importance in chilled meat preservation. The chemical compositions of natural spices are complex and their antibacterial and antioxidant effects are excellent.Both the domestic and foreign research shows that the preservation effect of spice extracts on chilled pork is remarkable. In this paper, the main chemical compositions and antioxidant activity of 3 kinds of spices(onion, pepper, Agastache rugosa) extracts by soxhlet extraction were analysised and the preservation effect of their extracts for chilled pork were also explored. The contents and results are as follows:1. The onion, pepper, ageratum were reflux extracted with 95% ethanol by soxhlet extraction. The chemical compositions of spices extracts were study by solution injection and headspace solid phase micro extraction technologies of GC-MS. The results showed that among 54 kinds of chemical compositions identified from onion extracts, sulfur-containing, amide, alcohols, acids, etc. had relatively high content. The main chemical compositions of onion extracts included most of sulfur ethers in sulfur-containing compounds((E)-1-Methylthio-1-propene, di-2-propenyl Trisulfide,di-2-propenyl Tetrasulfide) and 3,4-Methylenedioxy-amphetamine, Glycerin,2-methyl-Benzaldehyde, Cyclopentane-1,2-diol, n-Hexadecanoic acid etc. 73 kinds of chemical composition were determined in the pepper extracts, among the content of olefin, aldehydes, acids, ketones were relatively high. Alloaromadendren,4-methyl-benzaldehyde, Capsaicin, Dihydrocapsaicin, Methyllinolenate, Hexadecanoic acid, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-Pyran-4-one, Tetradecanoic acid,(Z,Z,Z)-9,12,15-Octadecatrienoic acid etc. were the main chemical compositions ofpepper extracts. The relative content of ethers, phenols and ketones were larger in 68 kinds of chemical composition confirmed from Agastache rugosa extracts. The main chemical compositions of Agastache rugosa extracts were estragole, eugenol,2-methoxy-3-(2-propenyl)-phenol, l-Menthone,(Z,Z)-9,12-Octadecadienoic acid,5-methyl-2-(1-methylethylidene)-Cyclohexanone etc..2. The antioxidant activity of 3 spices extracts were determined using DPPH method. The results indicated that as the concentration of onion, pepper, Agastache rugosa extracts raising, the clearance rate of DPPH free radical increased. And the difference of the clearance rate between different concentration were significant(P<0.05). Among the antioxidant activity of onion extract was the strongest; However,the antioxidant activity of 0.2-0.5 g/mL spices extract were greater than 0.016%commodity antioxidant-ascorbic acid(35.36%). When the concentration was 0.5 g/mL,the maximum of spices extracts antioxidant activity was 92.51%, less than 0.080%ascorbic acid(95.84%).3. The optimal concentration of 3 spices extracts were selected using single factor experiment method, and 7 kinds of single and compound preservation liquid were prepared to handle fresh pork, then the changes of sensory evaluation, colony counts of microbe, TVB-N value, TBARS value, pH value, color, tenderness and dripping loss were determined to study the quality changes of vacuum-packaged chilled pork during storage at(4±1) ?. The results revealed that the preservation effect of 0.5% onion,0.5% pepper and 0.3% Agastache rugosa alcohol extract were better at 15 d. With the extension of storage time, sensory evaluation, tenderness were gradually declined,colony counts of microbe, TVB-N value, TBARS value and dripping loss overall increased gradually, a* value, pH value rises firstly and then decreased(P<0.05). The sensory evaluation, shear force of 0.5% onion group, 0.5% pepper and 0.3% Agastache rugosa were relatively high, and colony counts of microbe, TVB-N value, dripping loss were relatively small. TBARS value of 0.5% pepper group, 0.5% pepper and 0.3%Agastache rugosa at storage were smaller. The a* value of 0.5% pepper group, 0.5%onion and 0.5% pepper were bigger. The pH value of 0.5% onion group rised gently,and 0.5% onion and 0.5% pepper was relatively high. The single preservation(0.5%onion) and compound preservation(0.5% pepper and 0.3% Agastache rugosa) have better preservation effect and the shelf-life of chilled pork was extended to about 23 days at(4±1)? with vacuum-packaged.In this paper the preservation effect of onion, pepper, Agastache rugosa extracts were determined. The results should be a great value in searching for natural substances to preserve chilled pork and extending its shelf-life.