Optimization Of Processing Technology Of Low Temperature Sauced Meat And The Effect Of Coating Preservation On Its Quality Abstract

Sauce stewed meat products are a traditional category of cooked meat products in China.They have rich flavor and attractive color,and are deeply loved by consumers.With the deepening of the research on sauced meat,the production process of sauced meat products is more mature,not only focusing on its taste,but also on the maintenance of nutritional value and the improvement of digestibility.However,at present,China ’s traditional sauced meat products have long curing time and uneven penetration in the curing process;there are some problems in the cooking process,such as serious protein denaturation,low digestibility and low yield.In view of the above problems,this paper intends to improve the process of sauced meat by ultrasonic assisted pickling combined with low temperature marinating,so as to improve the quality of sauced meat.In addition,considering that the sterilization is not complete during the low temperature processing,there are still some heat-resistant microorganisms surviving,and the ready-to-eat sauced meat in the market is mostly sold in bulk,and the product is perishable,resulting in a short shelf life.It is proposed to extend the shelf life of low-temperature sauced meat by coating preservation.In this study,pork was used as the research object to explore the effects of ultrasound-assisted curing and low-temperature stewing on the quality of sauced stewed meat,and to determine the best curing and stewing process conditions.In addition,sodium alginate was used as the matrix,and nisin and cinnamon essential oil were added to make a film solution,which was applied to low-temperature sauced stewed meat.The effect of the film solution on the quality of low-temperature sauced stewed meat during storage was explored,in order to provide experimental basis for the application of edible film in low-temperature sauced stewed meat products.The main research contents and results are as follows :(1)Effect of ultrasonic curing on the quality of low temperature sauced meatThe effects of different ultrasonic time,ultrasonic temperature and ultrasonic power on the quality of low temperature sauced meat were investigated by single factor test and response surface test.The results showed that increasing the ultrasonic curing power and ultrasonic time was beneficial to reduce the cooking loss rate and shear force of sauced meat.The response surface optimization was carried out with sensory score as the evaluation index.The results showed that the factors affecting the sensory score were as follows : ultrasonic time > ultrasonic power > ultrasonic temperature.The optimum process conditions were as follows : ultrasonic temperature 29 °C,ultrasonic time 70 min,ultrasonic power 230 W.Under these conditions,the sensory score was 88.56 ± 1.21,and the predicted value was in good agreement with the actual value.(2)Optimization of low temperature marinating process of sauced meatCombined with the best ultrasonic conditions obtained from the above exploration,the effects of marinating time,marinating temperature and meat ratio on the quality of sauced meat were further explored.Through the combination of single factor test and response surface test,the response surface optimization was carried out with sensory score as the evaluation index.The results showed that the factors affecting the sensory score were as follows : stewing temperature > meat ratio > stewing time.The optimum process was as follows : stewing temperature 81 °C,stewing time 91 min,meat ratio 2.2 %.Under this condition,the sensory score of low-temperature sauced stewed meat was 93.12 ± 1.45,and the predicted value was in good agreement with the actual value.The low temperature sauced meat under this process has fresh taste,rich taste,rich aroma and good quality.(3)Comparative analysis of low temperature sauced meat and traditional sauced meatThe sensory quality,physical and chemical properties and flavor of the low temperature sauced meat obtained by the above improved process and the sauced meat cooked by the traditional process were compared.The results showed that the hardness,elasticity,chewiness,shear force and cooking loss rate of low temperature sauced meat were lower than those of traditional sauced meat,and the in vitro digestibility,water holding rate and resilience of protein were higher than those of traditional sauced meat.Through microstructure analysis,it was found that the gap between myofibrils increased after ultrasonic treatment.Low field nuclear magnetic resonance(LF-NMR)analysis showed that ultrasonic treatment improved the fluidity and content of immobile water,which indicated that ultrasonic treatment had an effect on the structure of myofibrils,which was beneficial to the improvement of water holding capacity of stewed meat.From the principal component analysis of the electronic nose,there was no overlap between the data points of the two groups of samples,indicating that the volatile odors between the two groups were quite different.Headspace solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS)was used to detect low-temperature sauced meat and traditional sauced meat.It was found that a total of52 volatile flavor substances were detected in the two groups of sauced meat,including 16 aldehydes,10 alcohols,4 esters and 12 hydrocarbons.(4)Effect of coating preservation on the quality of low temperature sauced meat during preservationTaking the total number of colonies as the evaluation index,the influence order of Nisin,cinnamon essential oil and sodium alginate on the total number of colonies of sauced stewed meat was Nisin > sodium alginate > cinnamon essential oil by single factor and orthogonal test.The optimal coating combination was determined as : Nisin 0.025 %,cinnamon essential oil 2.5 %,sodium alginate 3.5 %.The optimized coating solution was applied to low-temperature sauced meat,and the uncoated group was used as the blank group.The two groups of samples were placed in a tray and stored in a refrigerator at 4 °C.The results showed that the total number of colonies,volatile base nitrogen(TVB-N),thiobarbituric acid reactive substances(TBARS),p H value and weight loss rate of the coating group were lower than those of the blank group during storage,which effectively delayed the deterioration of product quality and extended the shelf life of low-temperature sauced meat for 6 days.