| Along with the change of consumption concept and consumption demand,the customers have a higher requirement for the quality of freshwater fish.However,due to high moisture content and rich nutrients of the freshwater fish,it is easier to be decaying during the transport,storage,processing and sales.Tea polyphenols is a kind of natural preservatives and antioxidants which is in accord with the requirements of the "natural,safe and healthy".Therefore,it has been widely used in all kinds of food preservation.In this paper,Weever was selected as the the research object and the chemistry,microbiology,instrumental analysis and sensory methods were used to researched the effect of tea polyphenols on the physicochemical and sensory quality of it and then the weever shelf life prediction model was established to predict its quality.The main contents and conclusions of the research are as follows:(1).The evaluation indexes of total viable counts(TVC),2-thiobarbituric acid(TBA),total volatile base nitrogen(TVB-N),K value,pH value,shear force,whiteness and sensory indicators were selected to determine the effect of the four storage methods(air,vacuum,tea polyphenols and vacuum+tea polyphenols)on the quality of weevers.The results showed that in the whole treatment groups the values of the TVC,TVB-N,TBA,whiteness and K increased as the extension of time;the shear force and the sensory indicators decreased were just reverse;and the pH value increased at first and then decreased.However,compared with the another three storage methods,the combine of vacuum and tea polyphenols showed a lower values of TVB-N,TBA,whiteness,pH and K,but on the the contrary the shear force had a higher value.It indicated that the combine of vacuum and tea polyphenols had the best storage capacity for weevers during the storage and this conclusion had also been proved by sensory indicators.(2).The present study was undertaken to investigate the influences of vacuum+tea polyphenols on the quality of weever in cold chain logistics process by simulating the four different phase of the storage(-18 ?),transportation(0 ?),marketing(2 ?)and household refrigerator storage(4 ?).The result indicated that the vacuum+tea polyphenols had an obvious buffer action on the quality of weever in cold chain logistics process;At the end of the logistics(20 d),the values of TVB-N,TBA,total plate count an pH were significantly lower than the control group,and the shear force and sensory score values were significantly higher than that of control group which ensure the weever is still in the scope of the safety in the late logistics.(3).The effects of the combine of vacuum and tea polyphenols on the qualities of weever were further determined by analyzing the change of total viable counts,TVB-N,pH value,whiteness,texture,drip loss,organizational structure and moisture at-2 ?,0 ? and 4 ?,respectively.The results indicated that the vacuum+tea polyphenols can maintain the quality of weever at the three temperatures.(4).The fat oxidation index's change of the weevers back and abdomen fillet were researched on the condition of the three storage methods(air,vacuum,vacuum+tea polyphenols)at-2 ?,0 ? and 4 ?,respectively.and then the shelf life prediction model was set up.Based on the shelf life prediction model,the predicted values were received and it displayed a exact value with the RE <10.60%.Hence,the predictionmodel based on the fat oxidation index can exactly predict the storage period of weever and also can provide the reference price for weever storage. |
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