The Impact Of Capsaicin On The Lactobacillus And The Change Of Odors Of Fermented Pepper

Fermented pepper is a traditional fermented food in China. It had the feature of fragrant flavor and loved by everyone. The traditional method was used the microorganism which attached on the surface of pepper to ferment. This method has some shortcomings such as a long fermented time. During the fermented process, the impact of capsaicin on the Lactobacillus never been studied. This paper starts the study from the impact of capsaicin on the Lactobacillus; research the change of odors which use several different fermented modes, at the same time, comparing the change of odors before and after processing, and the following conclusions:First, this study using Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus reuteri, Lactobacillus helveticus, and Lactobacillus rhamnosus as the research objects. Investigate the main component of capsaicin in pepper and the salt mass concentration to the impact of capsaicin on the Lactobacillus. Combine with electron microscopy experiments to discuss the effect of capsaicin on the Lactobacillus. The result showed that the capsaicin can delay the growth of the Lactobacillus. Minimum concentration of capsaicin inhibited the Lactobacillus is0.133mg/mL. In this concentration, logarithmic phase of lactobacillus is delayed2h and as the concentration increases, the effect is more pronounced. By experiment of electron microscope we found a certain concentration of capsaicin could hurt the cells of Lactobacillus. Although, cells have the emergency response mechanism can recover normal after2h, when the Lactobacillus reach the stable the OD values will be reduced (OD600nm value decreased by0.2).Second, this paper use four different fermented methods (high-salt pickled, mixed fermentation, Lactobacillus plantarum fermentation, natural fermentation), analyze the physical chemical indicators and aroma components, study the fingerprint of the odor substances in the different fermented conditions, explore the differences that exist in different fermented environment. Total acid content is determined by titration, the hydrochloride naphthylethylenediamine method is used for the detection of nitrite, headspace solid phase micro-extraction combined with GC-MS method for the determination of aroma components. The results showed that adding microbial fermentation could decrease the fermented time and reduce the content of nitrite in fermentation of the late, and total acid content does not change too much. The common odor ingredients in four different fermented types of fermented pepper are ethanol,3,7-dimethyl-1,6-cyclooctadiene-3-alcohol,2-methyl-tridecane, pyrazine when ferment8d. At the same time, four kinds of fermented pepper in the early stage, ethanol content and acid content is relatively high. The common odor ingredients in four different fermented types of fermented pepper are ethanol,1-pentanol,3,7-dimethyl-1,6-cyclooctadiene-3-alcohol, pyrazine,2-methyl-tridecane when ferment16d. In addition to the high-salt pickled fermented pepper, another three fermented pepper flavor substances began to increase. The types of mixed fermentation is clearly reach the fermented late, because the flavor substances more than100kinds, the ester content is the highest in the four fermented types when ferment24d. So, the inoculated fermentation can increase the flavor of the type of substance, shorten the fermented time, and provide a theoretical basis for the industrial production of inoculating pepper.Third, this paper uses the same method to identify the chemical composition of the finished product in the high-salt pickled raw materials and the desalination finished products. The results showed that the common substances are pentanoic acid, hexyl ester,2-methyl-pentadecane, alpha.-longipinene. The highest organic component is the alcohols in the high-salt pickled raw materials, after desalination processing, alcohols transformed into esters, in the finished product the ester content is increased, especially a major component:ethyl caproate. Ethyl caproate content is51.062%after processing.