Research On The Shelf Life Prediction And Quality Control Of Quick-frozen Dumpling

This paper applied quick-frozen dumpling as experimental object,studying the quality change when the stored temperature went up and down andapplying the BP nerve net technolgy combined with the valid temperatureaccumulation theory to predict the shelf life of the quick-frozen dumplings. Byimitating the interrupt phenomenon of the cold stored chain and studying its effects onquality whose indices were conducted by an all-round analysis, we were lookingforward to providing the quality change of quick-frozen dumplings stored under lowertemperature condition with theory foundation. By testing the quality change underdifferent stored temperatures along with the physicochemical and microbe testingindices, we use weibull hazard analysis theory to predict the shelf life of thequick-frozen dumplings. The conclusion as follows:1. The quick-frozen dumplings were stored at temperature which fluctuated,ranging from-28℃to-12℃.The quality changeindices such as acid value, peroxidevalues, water amount of skin, white degree of skin and sensory appraisal were testedevery five days. BP nerve net technolgy combined with the valid temperatureaccumulation theory was applied to predict the shelf life of the quick-frozendumplings. As the result suggested, the predictive shelf life coincided well with thepractical one. The maximum error was3.18%, verifying the feasibility to predict theshelf life of quick-frozen dumplings using BP nerve net technology.2. We studied the quality change laws by imitating the interrupt of the cold storedchain while stored.The sample dumplings were stored at-18℃and were divided intotesting group and contrastive group, three same tests per batch. The contrastive groupwas stored at-18℃all along, the testing group, however, were stored for90min in thethermostat whose temperature was set25℃after being taken out from the refrigeratorwho has a stable temperature, and then back to-18℃environment. Every five days,three parallel experiments of sensory quality, colony of bacteria and physicochemicalindices were conducted and we took the average in the end. The testing group washigher obviously than the contrastive group when it come to the ascendant rate of theacid value and the per oxide value with time going by, and the colony of bacteria even more obviously. the physicochemical testing along with the sensory appraisal showedthat the interrupt of the cold stored chain had an obvious effect on the quality ofquick-frozen dumpling, promoting its spoilage and leading to a shorter practical shelflife compared with the normal condition.3. Take quick-frozen dumplings as experimental object and by sensory accepta-bility analysis applying weibull model and acceleration of shelf life theory, wepredicted the shelf life. The quick-frozen dumplings were stored at three different butconstant temperatures by-5℃、-10℃and-15℃, physicochemical testing and microbetesting were carried out at a stable intervals and the date was disposed by weibullhazard analysis theory, then we got a prediction model. As the result suggested, thepredictive shelf life coincided well with the practical one. The maximum error was3.57%.