Study On The Improvement Of Fermented Suirmi Flavor

Fermented surimi is an aquatic products with many advantages,such as uniqueflavor,high nutritional value, safety and long storage period.Therefore, in order to enhancethe level of fish industry’s processing and improve the production efficiency, we need todevelop a fermented surimi products with good flavor and high value-added under the helpof microbial fermentation agents’ unique physical activity. Many studies have been carried outagainst the variations of chemical composition in the fermentation environment and thechanges of protein structure especially the condensate chamber forming mechanism. Howeverthere is a big problem in the flavor of fermented products, particularly it’s too sour andirritant.The purpose of this paper is to explore the suitable starter bacteria and fermentationprocess to improve the flavor of fermented surimi, to provide the theoretical basis of popularsurimi products and promote the development of freshwater fish-processing industry.Firstly, choose the strains of Lactobacillus plantarum Lp-21, Staphylococcus xylose Sx-8and Saccharomyces cerevisiae Ss-8, selected from the traditional fermented product (suanyu).The changes of desnsity and pH value, enzymatic properties and antagonism of the startercultures were investigated; inoculated them into surimi respectively, study the change of pHand TBARS value and the influence on the texture, sensory quality and volatile compounds ofsurimi.It turned out that bacterial activity and acid producing ability of Lp-21was strong,while Ss-8also produced acid. Lp-21owned protease activity without lipase activity; Sx-8and Ss-8owned them both, there’s no antagonistic effect between the threemicroorganisms.After been inoculated into surimi, the pH in surimi with Lp-21decreasedrapidly, Sx-8had a strong inhibition of TBARS values’ rise, Lp-21can inhibit the growth ofvarious germs; the surimi inoculated in Lp-21and Ss-8got texture and sensory properties;Comparison to the46kinds of flavor compounds detected from the control sample, it hadbeen decetede53,48and49kinds of flavor compounds from the surimi with Lp-21, Sx-8andSs-8, the flavor improved significantly.Secondly, the change of pH, TBARS, TVBN and AAN of surimi samples weremeasured to look for the appropriate mixedt starter culture. When Lp-21, Sx-8and Ss-8werecomplex as the ratio of1:2:2, surimi’ physical and chemical properties were satisfactory andachieved better texture and sensory quality after the fermentation of48h.Simultaneously, we found that when the quantity of inoculation was2%, fermentationtemperature was30℃, the baking temperature was55℃, the added amount of salt, glucose,phosphate and spices were2.0%,2.0%,0.2%and0.5%, the product ownede the best textureand flavor.Finally, the influence of free amino acids, free fatty acids and volatile compounds on thefermented flavour was studied. Inoculated with Lp-21and mixed starter culture, the freeamino acids of samples were2.6and3.1times than the raw fish, essential amino acids raisedfrom93.74mg/100g of the raw to300.83mg/100g and375.98mg/100g, the nutritional valueof the product increased; the monounsaturated fatty acid decreased, while the polyunsaturatedfatty acid content increased after fermentation. Inoculated Lp-21and mixed starter culture,31 and44volatile compounds were detected from the surimi, alcohols, acids, aldehydes andother substances had increased because of the add of yeast,the flavor of the fermentedsausages improved greatly.