Research On The Optimization Of Fermentation Process And Quality Control Of The Red Sour Soup

Red sour soup marked by its soft sourness,delicacy and rich in aroma.With the industrialization of red sour soup,the problems of low organic acid content,stimulate sourness and single flavour are found,which doesn't accord with the characteristics of the red sour soup.At present,the control of the fermentation process is all based on experience.There are little research on the strain,fermentation technology and conservation measures of traditional red sour soup.It is the main reason resulted the deterioration problem like flower,expanding bag and unstable product quality.Besides,many manufacturers have developed the mixed-red sour soup,but the phenomenon of oil-water separation affected its sensory quality.This paper discussed the formula and process of fermentation,the stability of mixed-red sour soup and the flavour substances of the red sour soup.The conclusion as follows:(1)Adding spices could enrich the flavors of red sour soup.The sensory score and the total acid content were regarded as the index of tomato juice and hot pepper formula optimum fermentation.By the single factor experiment,the content of salt,glutinous rice in the tomato juice were 6%,2%.The content of salt,ginger,garlic and glutinous rice in the fermented hot pepper were 7%,3%,2% and 4%.With the the best formula,the red sour soup appear a soft and pure sourness,perfume strong and higher sensory score.(2)The organic acid of the semi-finished red sour soup was determined by using high performance liquid chromatography.Based on single factor and orthogonal test,the optimal culture conditions of the tomato juice were as follows: the starter strain of tomato juice was Lactobacillus acidophilus,Bacillus coagulant and Lactobacillus plantarum and the ratio was 1:1:1,inoculum size was 3%,fermentation temperature was 28?,culture time was 9d.Similarly,the optimal culture conditions of hot pepper were as follows: The starter strain was Lactobacillus pentosus,Bacillus coagulant and Lactobacillus fermentum and the ratio was 1:1:1,inoculum size was 2.5%,fermentation temperature was 28?,culture time was 10 d.Furthermore,when the proportion of tomato juice and hot pepper was 55:45,sensory score of red sour soup was highest,tastes palatable.With the best culture conditions,a product of gentle acid and stable quality could got.(3)In order to solve the deterioration problem of flower and expanding bag appeared in the production and sales of red sour soup,the conversation measures we took was adding sodium benzoate,vacuum-packed and pasteurization.Results showed the quality of red sour soup could be kept and effectively solved the bulging bag of red sour soup under the content of sodium benzoate 0.25g/kg,sterilization temperature of 75?,sterilization time of 15 min.(4)In order to solve the problem of oil-water separation,we investigated the effect of sucrose ester content,mono-glycerides content,emulsifying temperature,emulsifying time on the absorbance value and the amount of separated oil after centrifuge of emulsion of mixed-red sour soup using single factor experiment and response surface methodology.Results showed that the absorbance value of emulsion of mixed-red sour soup under the optimized conditions of 0.21% sucrose ester content,0.20% mono-glycerides content,64.7? and 3.09 min was experimentally measured as0.436.In this condition,the phenomenon of oil-water separation,is less likely to happen in the mixed-sour soup with high stability and better sensory quality.(5)The organic acids of red sour soup include lactic acid,citric acid,acetic acid,tartaric acid,oxalic acid,malic acid and acetic acid.The content of lactic acid is highest,which is the characteristic flavor component of red sour soup.159 kinds of volatile flavor compounds were found in commercial and homemade red sour soup.They were alcohols,esters,acids,alkanes,aldehydes,ketones,phenols,sulphur-containing compounds and other compounds.Alcohols,esters and acids highly contributes to the flavour of red sour soup.Besides,adding garlic,ginger into the red sour soup enhanced the flavour of red sour soup,which plays an important role in the fermentation process.There are similar kinds of amino acids in commercial red sour soup and homemade red sour soup,but the content is different.Glutamic acid is the source of fresh taste of red sour soup.