| Meat is essential food in daily life. Chilled pork is healthy and safety, soft and juicy, bright red color, delicious, and nutritional. Back in the fifties and sixties, chilled meat had been produced and selled by some developed countries. In the 80's of last century, China began to research and produce chilled meat, but because of the economic, technical reasons, progress was slow. With China's rapid economic development and people's demands to improve the level of meat consumption, chilled meat will account for more raw meat market.This thesis was an experimental study which was a partial study of a project on'technology innovation and equipment development of the green supply chain of pork products'of'Eleventh Five-Year'National 863 Plan:'key technology and products of food Green Supply Chain'. In this thesis the change of quality was measured when chilled pork was stored at different storage temperatures, kinetic models was studied, sensory array fingerprint analyzer atlas of chilled pork based on electronic nose and GC-MS was established, technical program and equipment of RFID technology were designed to full-time monitoring the quality of chilled pork in the cold chain. The main conclusion by this thesis is listed as follows:(1)The sensory and physiology of pork stored at 273K, 278K, 283 K and 293K were studied. Analyzing the chemical kinetics of quality, it was concluded that the T-VBN was conformed to the first order. It was well reflected the storage quality versus shelf-life, and selected as the quality standard. The activation energy Ea and Q10 would be calculated by Arrhenius model. By means of sensory evaluation, during (283K～293K), the function of shelf-life prediction at any temperature wasθs(T)=2.38×1.62(293-T)/10, while during (273K～283K), the function wasθs(T)=3.79×1.6(283-T)/10. Then the quality loss and remained shelf-life after different circulation temperature and time were got.(2)Electronic nose technology was used to identify freshness of chilled pork. Electronic nose was used to investigate change of volatile component of chilled pork under different storage periods and temperatures. Method of principal compounds analysis (PCA) and discriminate factorial analysis (DFA) were used to assess the freshness of chilled pork combining with changes of different physical chemistry index such as aerobic bacterial count and total volatile base-nitrogen (T-VBN). The shelf life of chilled pork at two storage temperatures (283 and 277K) was 2 days and 5 days respectively. The odor fingerprint based on the analysis of PCA and DFA was got. The time inflexion of the changes in the distribution of smell coincided with the shelf life of chilled pork. Application of electronic nose technology, through the fingerprints established by PCA and DFA analysis could well identify the freshness and shelf life of chilled pork. It was a foundation study for further experimental study on establishing shelf-life prediction model of chilled pork by using sensory array fingerprint analyzer technology.(3) The method of shelf life (SL) analysis of electric nose technology was used to investigate change of volatile component of chilled pork. The change of volatile component had good relationship with the change of physical chemistry index. Shelf-life prediction mold when pork stored at(273K～283K)was got by using SL, T-VBN analysis, Arrhenius kinetic model and the Q10 model, which was 10283-TSL =80×2.833(h). A foundation experimental study was done for further study on quality control and dynamic prediction of shelf life in chilled pork cold chain by using sensory array fingerprint analyzer technology.(4)The aim of this paper was to optimize the extraction conditions and determine volatile compounds of chilled pork by using solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Extraction conditions of SPME were optimized. SPME was used to extract volatile compounds of chilled pork which stored at different temperatures, then volatile compounds were identified by GC-MS. The change of volatile compounds of chilled pork under different storage time was analyzed. The volatile compounds of chilled pork were extracted by SPME using a 65μm PDMS/DVB fiber at 35℃for 40 min. 25 volatile components were detected and the relative content of Trimethylamine and Alcohols increased as the storage time increased.(5) Technical program and equipment of RFID technology were designed to full-time monitoring the quality of chilled pork in the cold chain. In this thesis, portable equipments of RFID readers and tags which based on a practical platform of MSP430 were designed, so that predicting the shelf life of chilled pork in cold chain was achieved... |
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