Screening Of Preservatives From Chinese Herb Medicine And Its Application In Chilled Beef Storage

This paper consisted of three parts:In part one, screening of preservatives from Chinese herbal medicines and its stability were studied. Thirty species of Chinese herbal medicines were extracted with 60% ethanol and the crude extracts were tested for their antimicrobial activity on Escherichia coli, Staphylococcus aureus, Bacillus cereus, Candida albicans and Mucor racemes by agar diffussion method. The results demonstrated that five species, Salvia miltiorrhiza Bunge., Scutellaria baicalensis Georgi., Isatis iudigotica Fort., Dendranthema indicus (L.) Des Moul. and Prunus mume (Sieb.) Sieb. Et zucc. showed inhibitiory activities as well as wide antibacterial on the tested microorganisms. Their spectra inhibitory effects were equivalent with those of the chemical control 0.2% potassium sorbate. Among them, the Salvia miltiorrhiza showed remarkable inhibitory activities to the Staphylococcus aureus, Escherichia coli, Mucor racemos, and the inhibition zone was up to 18mm, 17mm, 25mm, respectively. Ten matching liquors were prepared by the above five extracts, and their antimicrobial activities on the tested microorganisms demonstrated that the matching liquor, FP1 and FP6 showed better inhibitory effect than single extracts.Experiment of stability showed that DS, FP1 and FP6 were allowed to be stored without light, and the optimal pH value were 6. DS and FP1 were stored for less than 5d at ambient temperature (25±3℃), FP6 were stored for less than 10d at ambient temperature (25±3℃).In part two, the application of Chinese herbal medicines in preservation of chilled beef was investigated. The results of DS, FP1 and FP6 on chilled beef showed that preservative liquors possessed significant fresh-keeping effects on sensory, microbial and physiochemical value of the chilled beef compared to the control testing. The matching liquor FP6 possessed better keeping-fresh effect than that of DS or FP1. FP6 combine with nanometer film could prolonged the shelf life of chilled beef for 15d.In part three, the content of active component tanshinoneⅡA in preservative was determined by HPLC method. The chromatographic conditions were: C18 column (250mm×4.6mm, 5μm, Phoxmen), the methanol-1% acetic acid (85:15) as mobile phase with 1.0ml/min flow rate, the detection wavelength selected as 254nm, and the column temperature set at 30℃. The result showed that TanshinoneⅡA in 60% ethanol showed good linear relationship within 1.0-50μg/m(lR=0.9997), The retention time of tanshinoneⅡA in HPLC was 9.45±0.1min. The method is simple, sensitive and accurate, and it can be used to determine tanshinoneⅡA content in the preservative effectively.