Study On Production Of Fermented Lamb Sausage With Direct-acting Compound Starter

With goat meat as raw material,add a certain amount of Pediococcus acidilactici(PA)powder and Rhizopus oryzae spore powder(RO)based on the traditional production of lamb sausages to reduce odor and improve mutton sausage flavor.The use of optimal process to prepare blank without starter(CO),blank plus starter(CO+PR),blank and traditional spices(SG),blank and traditional spices mixed with starter(SG+PR)for flavor and fatty acid analysis.The main findings are as follows:(1)Pediococcus acidilactici and Rhizopus oryzae stable growth in both 24 h,and Pediococcus acidilactici and Rhizopus oryzae grown at an amount of 1.5% salt were not inhibited.The process optimization of bacterial powder preparation was carried out,and the optimum technological parameters for preparing the bacterial powder were as follows: trehalose 10%,skim milk 10%,mannitol 6.5%,and the survival rate of Pediococcus acidis reached 77.07±.2.45%,the active bacteria number of Pediococcus acidilactici was 108 cfu/g.10% trehalose,12.5% skim milk,and 6.5% glycerol.Under these conditions,the survival rate of R.oryzae spore powder can reach 73.57±3.51%,and the active bacteria number of R.oryzae is 107 cfu/g.(2)The prepared starter is applied to the preparation of mutton fermented sausage.The effect of PA/RO ratio,inoculum size,fermentation temperature and time on the p H value,color and sensory evaluation of sausage was investigated by one-factor-at-a-time method.Subsequently,PA/RO ratio,added amount,fermentation temperature were optimized using response surface methodology with a three-factor,three-level Box-Behnken design(BBD).The response variable was sensory score.A fermentation time of 16 h,temperature of 32 ℃,a PA/RO ratio of 1:1 and an inoculum size of 2.2% were found to be the optimum processing conditions to obtain a higher sensory score of 6.34,agreeing with the model predicted value.The sausage prepared using the optimized conditions had moderate acidity(p H 5.2-5.3)and showed no significant difference in color difference as well as improved sensory quality and reduced mutton smell compared with the uninoculated and fermented sausage.(3)The use of optimal process to prepare blank without starter(CO),blank plus starter(CO+PR),blank and traditional spices(SG),blank and traditional spices mixed with starter(SG+PR)for flavor and fatty acid analysis.The results showed that 16 fatty acids were detected in 4 groups.The most abundant mutton fatty acids in fermented sausage fatty acids are C18:1n-9,C16:0,C18:0 which account for 41.492%,24.977%,and 17.672%.The sum of these 3 fatty acids exceeds 80% of the total amount tested,and the content of these three fatty acids are not affected by the addition of spices or added spices.C18:2n-6 is the most abundant polyunsaturated fatty acid.The C18:2n-6 content in the fragrance group(SG,SG+PR)is higher than that in the blank group(CO,CO+PR)after adding the flavor,possibly due to the spice Has antioxidant effect slows the oxidation of C18:2n-6.There were 39 volatile flavors detected by 4 groups of lamb fermented sausages.After analysis of principal components,there were 29 kinds of characteristic flavors of lamb fermented sausages.After analysis,it was found that the C18:2n-6 oxidation product was reduced after adding PA and RO to the mutton fermented sausage,which was consistent with the fatty acid measurement results.The addition of spices in lamb sausages can effectively inhibit the oxidation of fats,and increase the aroma substances such as terpenes to mask the bad taste of lamb,and improve the flavor quality of lamb fermented sausages.