Studies On The Process Technology And Product Characteristics Of Fermented Dry-cured Beef

Dry-cured beef is a characteristic traditional fermented meat product in southwest of China, consumers love it because of its delicious taste, unique flavor, fresh and not greasy, long shelf life. By advances in food processing technology, fermentation technology for starter will gradually replace the natural fermentation technology. In this study, optimize the dry-cured beef’s technical formula and technical condition, use the mixed microorganism agent of lactic acid bacteria and Staphylococcus to produce fermented dry-cured beef, research the physical, chemical and microbiological changes of dry-cured beef during processing and storage, study dry-cured beef’s volatile flavor compounds changes in different stages of processing, and investigate products’storage stability by different sterilization conditions. The main conclusions are as follows:1. Study on single factor experiments and orthogonal test with four kinds of influence factors of composite phosphate, salt, glucose, sodium ascorbate, sensory testing as an evaluation index, determining the optimum process parameters of dry-cured beef are glucose1%, compound phosphates0.3%, sodium ascorbate0.03g/kg, salt content3.5%.2. Study on the fermentation properties of lactic acid bacteria PP, LS85, C50-6and staphylococcus S25, results showed that the four strains of the optimum growth temperature of35℃, it is advisable to cultivate48h, choose PP, C50-6lactic acid bacteria and staphylococcus S25as mixed strains of leavening agent.3. Study on single factor experiments and orthogonal test with three kinds of influence factors of fermentation temperature, inoculation quantity, baking temperature for dry-cured beef processing conditions, sensory testing as an evaluation index, the results are the best fermentation temperature is15℃, the best inoculation quantity was3%, the best baking temperature of55℃.4. Researching on quality characteristics of dry-cured beef in processing with hybrid leavening agent are studied, natural fermented dry beef as reference substance, sensory, physical and chemical, microbial indicators was measured. Results showed that during the whole processing, the quality of the experimental group is better than the control group. Before fermentation, fermentation, after baking three stages, the control group and experimental group of volatile flavor compounds were detected,87,70,82and69,102,92, the same component can be divided into33,61,39species in three phases. The volatile flavor compounds of the experimental group product was significantly higher than control group, difference of the two component relative content is not obvious. The main advantages of flavor compounds are Myrcene, Cinnamene, D-Limonene,(E)-Ocimene,2-Carene, Limonene monoxide, trans-Sabinene hydrate,1-Caryophyllene,(-)-b-Cadinene, d-Cadinene, Perillene, Phytene.5. The fermented dry-cured beef by the mixed fermentation agent with vacuum packaging are divided into5groups, and respectively by means of heat sterilization, chemical additive, heat+chemical additive, ultrahigh pressure to extend the shelf life of processing, vacuum packaging products as the control group, Assaying physical and chemical, microbial index, simultaneously doing sensory evaluation, analysis in the37℃storage process quality changes. The results show that the sensory evaluation of heat sterilization, heat+chemical additive group was significantly higher than the chemical additive, ultrahigh pressure group and the control group. Chemical additive, ultrahigh pressure and the control group were no significantly difference overall throughout the storage period.In the course of the entire storage, the test group and the control group’s pH, moisture content, nitrite content decreased significantly, TVBN and acid value all increase significantly, peroxide value is not detected. The control group and the heat sterilization group and the chemical additive group and the ultrahigh pressure group’s pH have no significant differences, also no significant differences with chemical additive group which’s pH is lowest, the moisture content of the two groups has little differences, the nitrite content and TVBN and acid value of the control group was significantly higher than the test group. In the test group, the nitrite of the chemical additive group is lowest, the nitrite of the heat sterilization group and the heat+chemical additive group are middle, the nitrite of the ultrahigh pressure group is highest. TVBN, acid value of the heat+chemical additive group are lowest, TVBN, acid value of the heat sterilization group and the ultrahigh pressure group are middle, TVBN and acid value of the chemical additive group are highest. Throughout the storage period, L*value has little differences with the test group and the control group, the trend is upward in the overall, a*value of the test group is generally lower than the control group’s a*value, the trend is downward in the overall, b*values of the test group is generally lower than the control group’s b*value, b*value showed a downward trend. The color of product of the ultrahigh pressure group is the worst. The numbers of total bacterial count and yeast count of the control group and the test group were declining, the two groups detected little mold, the products of five groups are all qualified products. The numbers of total bacterial count and yeast count of the test group are lower than the control group, the heat+chemical additive group is lowest, then the heat sterilization group and the ultrahigh pressure group are lower, the chemical additive group is highest.In this paper, we do more systematic study for dry-cured beef’s formulation and process optimization and fermentation and antiseptic approach. The results can provide some basic data to promote dry-cured beef’s industrialization and large-scale for the enterprise, as well as provide antiseptic method to extend the shelf life of products, has certain theoretical significance and practical value.