Study On Preparation Of Sausage Dry Fermentation Agent

Fermented meats are nutritious,with special flavor and a long shelf-life,which are popular among consumers and have a good potential for industrialization.With the rapidly development of fermented meat product industry, it is of significant for promoting the industrial process of starter, improving development of fermented meat product;In order to get dry powder starter with a large number of 1ive cells and easy to use,the medium,culture conditions,protecting agent for powder starter were studied in this experiment.High concentrated freeze-dried bacteria ferment was made and freeze-dried starter cultures in sausage fermentation was tested.Using the single factor and orthogonal tests,the compositions of the optimum enrichment media for staphylococcus lugdunensis was:the basis of the MSA medium with 1.5% yeast extract,0.5% Tween 80,3.0% tomato juice,0.2% CaCO3,the cell density could reach 5.16×109cfu/mL in this medium.We determined the optimal culture conditions is:2% inoculum,initial pH value of 6.5,the temperature is 35℃,liquid volume 50mL(250mL),shaker rotation 150r/min,and also determine the fermentation for 18-20 hours as the best harvest time.By centrifugal rotation and time of inspection,the optimum centrifugal condition for staphylococcus lugdunensis was 10000r/min,10min,the harvest rate was 96.78%.The optimum compositions of freeze-dried protectant for staphylococcus lugdunensis were:10% mannitol matrix+1.5%L-sodium glutamate+10% glycerol,5% sucrose on the basic culture of 8% NFM,the survival rate was 89.66%.Freeze-dried powder storage performance results show that the fermentation agent stored in a vacuum,4℃,under which conditions the number of viable cells decreased at least.Determination of physical and chemical indicators of fermented sausage show that:the control group,liquid fermentation and dry fermented sausages groups moisture content,pH,and water activity decreased during ripening.In this study,70 major flavor compounds were detected which includes 7 kinds of acids,13 kinds of aldehydes,12 kinds of alcohols,3 kinds of ketones,11 kinds of esters,12 kinds of hydrocarbons and 12 kinds of heterocyclic;Compared with the control group,the total types of volatile compounds detected in the liquid and dry fermentation group are significant different,of which the liquid fermented sausage sample group of volatile compounds detected in a total of 51 species, dry powder 52 species,while the control group only 34.Sensory evaluation showed that:dry and liquid fermentation groups are better than the control group,these two groups in the overall acceptance were no difference between the terms.Comprehensive results show that the dry powder prepared by this experiment can be used as starter cultures for ferment sausage production.