| When the tray cold-fresh meat sold in the domestic supermarket gains popularity gradually, the study on shelf-life extension of the chilled meat and preserving its quality has become a hot topic in meat science. There is a lot of leachate soaking from the chilled meat in the long period of storage. This would not be only affect the sensory quality of the chilled meat, but also cause high relative humidity of the microenvironment in the packaging. It’s also easy for microbe to breed and reduce the shelf-life of the chilled meat. This study utilized several inhibition constituent that volatile from natural spices materials by brokening the wall, and prepared a simple meat pad with natural spices micropowder and sodium carboxymethylcellulose absorbent film. Referring to the salver packaging, it has an antimicrobial atmosphere formed in the confined space of packing tray and extends the shelf-life.This paper consisted of four parts. Part one is screening the micropowder from natural spices materials and proving the best particle size. Part two is the influence of technology factor of antimicrobial pad prepared by konjac glucomannan and chitosan on inhibiting effect. Part three is the preparation of antibacterial meat pad with super absorbent and the application of chilled meat preservation. And the last one is the preliminary study on release mechanism of micropowder from natural spices materials. The main results indicated as fllows:Part one:Nine powders from natural spices materials were tested for their antimicrobial activity on E. coli, S. aureus, B. thermosphacta, L. rhamnosus and P. fluorescens. The results demonstrated that clove and cinnamon powders showed inhibitory activities as well as wide antibacterial on the tested microorganisms. Clove and cinnamon powders showed a strong antimicrobial activity showing a minimum inhibitory concentration (MIC) against five spoilage organisms ranging from 1.5%,1.5%,2.0%, 1.0%,1.0% and 1.0%,1.0%,2.5%,1.5%,1.0%, respectively. The inhibitory effect of two powders firstly increased and then decreased with the decreasing particle size. Therefore, the best particle size of clove and cinnamon powders against spoilage organism were 14.39μm and 11.19μm, respectively. Part two:Clove and cinnamon powders screened above were selected for further experiment. A various of antimicrobial pads were prepared by konjac glucomannan, chitosan and powders at different sol mass, pH value, agitation temperature, drying temperature. They were tested for their antimicrobial activity on E. coli, S. aureus, B. thermosphacta, L. rhamnosus and P. fluorescens. The results showed that sol mass and pH values had a significant effect on microbial indicator during the storage of chilled meat. However, agitation temperature and drying temperature did not significantly influence the inhibitory effect of lining. Hence, the 90g sol mass,30℃agitation temperature of solution,3 of pH values and 65℃of drying temperature were selected for the best technology of pad.Part three:The pH values of sodium carboxymethylcellulose sol were adjusted by several edible acid, and super absorbent films were prepared by ester crosslinking method. The study focused on the absorb capacity (distilled water, saline and simulative blood), and clove and cinnamon powders used in part one were added to prepare two super absorbent pad of chilled meat. Compared the antimicrobial pads with cinnamon and clove oils, inhibiting effect of pad prepared by konjac glucomannan, chitosan and powder was evaluated. When the pH values of CMC film was 4.6 adjusted by citric acid, had the largest absorb capacity. The pads with cinnamon and clove oils were superior to pads with powder before 6 days. But inhibiting effect decreased with essence oil releasing. The pads with clove powder gained the best inhibiting effect and could extent the shelf life of chilled meat to 10 days.Part four:The release laws of eugenol and cinnamic aldehyde in clove and cinnamon powders were determined by ultraviolet-visible pectrophotometer. Compound release model was used to study the release of antimicrobial composite, which provided a multi-level release process. Then the law of release became clear and we can understand the release trend precisely. |
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