| Salted fish is one of the traditional salted meat products in China,this product has a unique flavor and is also easy to store and occupies a high position in Chinese food culture.Although Sichuan is a big province for freshwater fish breeding,there are some problems in the processing of freshwater fish,such as small processing share,backward processing technology,insufficient innovation in traditional processing and so on.With the background of Sichuan’s aquatic resources becoming more and more abundant,industrialization optimization and product innovation research on freshwater fish traditional salted products to develop better quality and safer cured salted fish has become the research focus of traditional freshwater fish products In this paper,grass carp was used as experimental material to compare the effects of different curing processes,air drying processes and different natural air drying parameters and natural plant extracts instead of nitrite on the physical and chemical properties and flavor of salted fish.The results are as follows:According to the research on the curing process of salted fish,the influencing of curing process factors are: salting salinity> pickling time> pickling temperature.The optimal parameters of the salted fish curing process are 3d pickling time,6 °C curing temperature,5.8% salting salinity,and the sensory score of the product under the optimized process is 93.02 points,and the relative error between the theoretical prediction value of 93.26 points is 0.26%,the model parameters obtained by response surface optimization are true and reliable,which can reflect the influence of various curing process parameters on the sensory evaluation of salted fish.And then,the effects of different drying processes on the characteristics of the cured fish products have compared.The studies showed that the acid value(AV:Acid Value)of the baked product is lower than that of the natural air drying,and its pH value,POV(Peroxide Value)and thiobarbituric acid value(TBA:Thiobarbituric Acid Value).Are significantly higher,the volatile base nitrogen value(TVB-N:Total Volatile Base Nitrogen)is not significantly different,and the air-dried product has a lower fat oxidation rate.About flavor,the difference in free amino acid content between the two drying processes is not significant,but baking drying is more conducive to the decomposition of proteins into free amino acids and its products’ Total Free Amino Acid(TAA),essential amino acid(EAA:Essential Amino Acid),DAA(Delicious Amino Acids)are slightly higher than the cold air drying group.According to the volatile flavor components,the volatile flavor substances andtotal relative content of salted fish under natural air-drying conditions are higher than that of hot air baking drying products,especially aldehydes and esters which are propitious to the flavor of the product.And natural air drying favours to the formation of flavor substances of the salted fish.In terms of product color characteristics,the natural air-drying product has a more rosy color,a lower hardness,a higher elasticity value,and a better sensory characteristic.The results of the natural air drying method’s single factor test show that the quality of the cured fish is the best under the conditions of air drying temperature of 8 °C,humidity of 45% and wind speed of 3 m / s.The factor analysis and response surface optimization experiment of the cold-air air-drying process parameters of salted fish are carried out,and the dependent variables that affected the comprehensive score F of the salted fish are: air drying speed > air drying temperature > air drying humidity.The optimum process of the salted fish imitation natural air drying optimization experiment is air drying temperature 8.94 ° C,humidity 47.32%,wind speed 1.79 m /s.And then,the overall merit score of salted fish is 0.6814.Combined with practical production of industrialization,the optimal process is adjusted to air drying temperature of 9 °C,humidity of 47%,and wind speed of 1.8 m/s.The characteristics of the optimization process parameters cured fish products are in the preferred range.Then,this part use the commercial natural plant extract T10(main ingredients including lemon,lime,sweet orange,rosemary,grapefruit,pomegranate extract,etc.)and DV(dehydrated vinegar powder,malt Dextrin,etc.)to replace the nitrate salt to carry out research on the influence of product characteristics.The results show that,compared with conventional addition of nitrite,natural nitrite substitute is superior to traditional nitrous oxide in terms of safety,its nitrite residue of salted fish and the total number of colonies during storage are significantly lower;In terms of hair color,the natural substitute T10 is better than DV and has similar effect with nitrite;while in terms of product quality and inhibition,nitrite has the best effect,T10 is the second,and DV has the worst bacteriostasis,but both within the limitation of standard.It shows that natural plant extracts can replace the role of nitrate salt in color,antioxidation,antibacterial and anticorrosion in a certain range.The application in other meat products needs further exploration.The subject adopts the imitation of natural cold air drying to improve the traditional processing method of salted fish,and further studies on the effect of replacing natural phytic acid with nitrite on the basis of process optimization,which could provid the possibility for the green color of traditional salted fish products,it canalso provide new ideas for the improvement of other meat processing technology and product quality improvement. |
