Study On Restructuring Of Dried Fish Floss And Quality Control Technology

The dried fish floss has high nutrional values and great flavor but has shortcomings in organization and taste.Therefore,the aim of this thesis was how to retain the inherent advantages of dried fish floss while develop a series of convenient and high-value ready meal products in order to meet the strict needs of consumers.In this paper,the main formula(fructose syrup,soybean protein and moisture)of products was optimized by orthogonal experiment with tuna dried fish floss as main raw material and fructose syrup as adhesive.After comparing,75?hot air drying for forming of products was determined.For further improvement of products,the influences of quality by adding different food additives(sugar alcohols,natural pigments and antioxidants)were studied.The feasibility of edible filming technology used for raising the quality of dried fish floss products was also investigated.Meanwhile,the changes of quality under different storage conditions of dried fish floss products based on chromatism,TVB-N,TBA,POV value and total plate count were investigated.The results were showed as follows.(1)The difference of products quality by usingfructose syrup,sugar syrup,starch syrup were compared.The results showed that sensory quality of product had improved obviously by adding fructose syrup.The product presented favorable texture,color and flavor through this way.The forming processwas determined primarily as following order:adding water to soybean protein?adding dried fish floss?syrup bonding?molding by machine?drying,and then the final product were formed.The orthogonal design was used to determine the optimum compositions:dried fish floss 36.7%,soybean protein 30%,fructose syrup 13.3%and water 20%.Two different dehydration methods for the products were compared,the result revealed that hot-air drying was better than vacuum drying.Changes of sensory value,moisture content,the degree of fat oxidation,color of the productswere analyzed.Results showed that drying in heat pump at 75?can ensure the best product quality.The moisture content was 13%on this optimum occasion.(2)The influences of water activity and the sensory evaluation by adding two different sugar alcohols were studied.Theresults showed that the glycerin was better.The effect of color changes with carrot pigment,capsicum red pigment and sorghum red pigment in different storage conditions had been compared.Carotene was chosen as the final natural pigment additive in this product.Also,the effect of fat oxidation of products with four antioxidant of TBHQ,BHA,V_C and tea polyphenols had been compared.The result showed that TBHQ had the strongest antioxidant effect in this product.(3)The effect of sensory properties,moisture rate,TVB-N and total plate count with two kinds of film materialsof products had been compared.The results showed that the products which filmed had better appearance,color and texture than before.Combined with the change of moisture absorption rate,TVB-N,total plate count,the conclusion showed that soybean protein isolate film to product was better one.Optimizing by volume of addition,filming amount and recombination of soybean protein isolate respectively and the conclusion showed that the optimum volume of addition was 10 g/100 ml,filming amount was 0.15 g/cm~2,and composite membrane of soybean separation protein and lipid(bee wax)was more suitable for this product.The contents of volatile flavor components of dried fish floss products were contrasted before drying,after drying and filming respectively.The results showed that the flavor compounds changed a lot after drying,and the relative content of ketones increased while aldehydes and hydrocarbon decreased after filming.It indicated that filming had an effect on flavor of the products.(4)The influences of different packing and light conditions on the color,TVB-N value,fat oxidation and the total plate count of products of dried fish floss products were studied.Vacuum packing and dark condition showed the best quality in color,TVB-N,TBA,POV value,followed by ordinary packing and dark condition.The samples which had been stored at ordinary packing and sunlight condition showed the worst quality in storage stability.Therefore,vacuum packing and dark condition revealed the best storage stability of product.The effects of different storage temperature on the quality of dried fish floss products were also studied.The lower the temperature,dried fish floss products had better storage stability.Simultaneously,low temperature helpedto keep the color of products and reduced the rate of fat oxidation,slowed the growth of microorganisms and extended the shelf life of products.According to the related national standards and industry standards of this product,quality and safety had been also evaluated and analyzed.