| Fresh and wet fish noodles is a new type of fish noodles based on the traditional fish noodles.It is not only nutritious and delicious,but also has the advantages of instant brewing and convenience that traditional fish noodles do not have.On the one hand,it can increase people’s nutritional intake,on the other hand,it also meet modern people’s requirement of food,so it is popular with consumers.However,many problems such as poor taste,easy corruption and short shelf life have restricted the industrialized production of fresh and wet fish noodles for a long time.Therefore,it is of great significance to study how to improve the quality of fresh and wet fish noodles,improve the storage characteristics of fresh and wet fish noodles and prolong the shelf life of fresh and wet fish noodles.This paper took fresh and wet fish noodles as the research object,process optimization,composite preservatives and composite preservation technology were studied to improves the storage characteristics,and constructs the shelf-life prediction model of fresh and wet fish noodles.The main research contents and results were as follows:(1)The effect of corn/cassava composite starch on the overall quality of fresh and wet fish noodles was studied.The results showed that when the proportion of cassava starch in fresh and wet fish noodles was 20%,the hardness of fresh and wet fish noodles decreased by 5.39%,the chewability increased by 3.60%,and the yellowness value decreased by 26.3%.The cooking quality,rheological properties,gelatinization properties and microstructure properties were significantly improved.However,with the continuous increase of the proportion of cassava starch,the viscosity of fresh and wet fish noodles increased,the texture was soft,and the overall quality decreased,The optimum ratio of compound starch was determined as corn starch:cassava starch=2:1.(2)The effects of compound antiseptic and compound organic acids on the quality and storage characteristics of fresh and wet fish noodles were studied.Four kinds of food preservatives were selected:glycerol monooctanoate,potassium sorbate,calcium propionate and nisin.The infrared spectrum analysis showed that the addition of food antiseptic had almost no damage to the starch and protein structure of fresh and wet fish noodles.Single factor experiments showed that different food antiseptic could maintain the texture characteristics,reduce TBA value during storage and inhibit the growth of microorganisms.The orthogonal experiment showed that the best formula of compound preservative was glycerol monooctanoate 0.75 g/kg,potassium sorbate 0.50 g/kg,calcium propionate 0.25 g/kg and nisin 1.00 g/kg.However,relying on composite preservatives can not significantly improve the color characteristics of fish noodles during storage.Therefore,lactic acid and citric acid were selected to form composite organic acids.The results showed that acid leaching treatment was better than addition.When the concentration of composite acid was 0.3%and lactic acid:citric acid=1:1,the color protection effect was obvious,and it can cooperate with composite preservatives to make it play a more significant antibacterial effect.(3)The effects of compound preservation technology on the quality and storage characteristics of fresh and wet fish noodles were studied.The composite preservation technology was acid leaching,vacuum packaging and high temperature sterilization were optimized by box Behnken response surface experiment.The single factor results showed that high temperature sterilization had the best effect on improving the storage characteristics.Acid leaching treatment had significant color protection effect,inhibited browning during storage,changed the p H value,and cooperated with compound antiseptic to further inhibit the growth of microorganisms.The effect of vacuum packaging was slightly worse than the first two;Based on the comprehensive score of each index,three different preservation processes were optimized by response surface methodology.The best composite preservation technology was obtained.When the acid leaching time was 3.82 min,the vacuum pumping time was 2.89 s and the high-temperature sterilization time was 29.47 min,the comprehensive score of fresh and wet fish noodles reached the best value of 92.3073 points.(4)The shelf life prediction model of fresh and wet fish noodles was established according to the changes of whiteness value,TBA value and TVB-N value of fresh and wet fish noodles under the storage conditions of 4℃,25℃and 37℃,the zero-order and first-order kinetic models were used to fit the changes of indexes during storage,and then the shelf life prediction model of fresh and wet fish noodles based on chemical reaction kinetics was obtained by Arrhenius equation;According to the change of the total bacterial count,the modified Gompertz model and the modified logistic model were compared,and the fitting degree of the two models to the data was compared.The results showed that the R~2,RMSE,AIC and BIC values of the modified logistic model was best.Therefore,the modified logistic model was selected as the first-order model,and then the belehradck square root model was used to fit the parameters of the modified logistic model.Then the shelf life prediction model of fresh and wet fish noodles based on microbial growth kinetics was obtained.The results showed that the shelf-life prediction model based on bacteria growth during storage had higher accuracy.At 4℃,the predicted shelf life was 159 days,which was 2.52%lower than the measured value;At25℃,the predicted shelf life was 117 days,which was 7.69%different from the measured value;At 37℃,the predicted shelf life was 94 days,which was 2.13%lower than the measured value.The model error was small,which can provide a certain reference for the production of fresh and wet fish noodles. |
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