Study On Fermented Chili Sauce Based On High Density Culture Of Lactic Acid Bacteria

This study screened the high-nitrite degradation rate of pepper sauce fermentation bacteria,using Xinjiang traditional fermented food kumis as the screening source,using traditional strain screening method combined with Atmospheric Room Temperature Plasma mutagenesis technology.In this study,high-density culture of strains and direct-injection starter were studied to optimize the fermentation process of chili sauce.The specific research results are as follows:(1)A strain of Leuconostoc mesenteroides C27 was screened from kumis by traditional screening method,and its nitrite degradation rate reached 88.91%.Using ARTP technology to induce the strain C55,a strain of Lactobacillus plantarum Y20 with good genetic stability was screened,and its nitrite degradation rate reached 95.40%.The acid and bile salt resistance test showed that the strains Y20 and C27 had better acid And bile salt tolerance,are expected to play a role in the colonization of human gastrointestinal tract.(2)By comparing the pH,reducing sugar and total acid content in the fermentation process of inoculation of different strains of chili sauce,it was found that the inoculation fermentation,especially the mixed fermentation of C27:Y20 with 1:1 compounding,can shorten the fermentation cycle.The peak size of nitrite shows that inoculating fermentation can reduce the content of nitrite and shorten the peak time,so that the chili sauce can quickly reach a safe shelf life.The volatile substances in the fermented pepper sauce of different strains were measured by Gas chromatography mass spectrometer,and 62 compounds were detected.The relatively high content of the four fermentation methods is isomenthone and aromatic alcohol.The 1:1 compound mixed fermentation detected the most volatile substances,followed by natural fermentation,cocci fermentation,and finally bacillus fermentation.The 1:1 compound mixed fermentation produced more terpenoids,alcohols and ester compounds than natural fermentation,indicating that the 1:1 compound mixed fermentation increased the flavor of the chili sauce.(3)In order to achieve high-density culture,the medium formula and culture conditions of Y20 and C27 were optimized.The optimal carbon,nitrogen,nitrogen,growth factors and addition amounts of strain Y20 was:sucrose 15.00 g/L,yeast dip powder 25.00 g/L,corn juice 16.00 g/L.The high-density culture conditions of Y20 were:fermentation temperature 33.60℃,pH 6.60,inoculum amount 1.20%(v/m),and the viable cell count of Y20 was 2.63×10~9 CFU/ml.The optimal carbon,nitrogen,nitrogen,growth factors and addition amounts of strain C27 was:sucrose 21.00 g/L,yeast dip powder 22.00 g/L,potato juice 14.00 g/L.The high-density culture conditions of C27 was fermentation temperature 38.40℃,pH 6.20,inoculum amount 2.40%(v/m),and the viable cell count of C27 was 1.30 x 10~9 CFU/ml.(4)The cryoprotectant formulations of strains Y20 and C27 were optimized using the the Simplex Centroid Design.The optimized protective agent formulations were:Y20 was 10.00 g/L sodium glutamate solution,and the cell viability under the protective agent was 70.40%;C27 was 10.00 g/L skim milk solution,and the cell viability under the protective agent was 56.32%.(5)The direct-injection starter of Y20 and C27 was inoculated into the chili sauce in a 1:1 ratio and the fermentation process was optimized.The optimal fermentation process of the chili sauce was as follows:the inoculum of the mixed bacteria(1:1)was 0.30%(m/m),the salt concentration is 7.00%(m/m),the fermentation temperature is 28.00℃,and the fermentation cycle is 8 days.Under this condition,the sensory score of the fermented chili sauce is 94.20 and the total acid content is 1.35 g/100 g.And the chili sauce has a rich fermentation flavor,soft and sour taste,and unique flavor.