| Soybean-flavor liquor is a unique wine in the Pearl River Delta region.It has strong local characteristics,and its meat immersion is an important process for forming unique flavors.The existing production process was formed according to the experience passed down from generation to generation.At present,the research on the mashing process of aged meat mainly stays at the physical and chemical index,and the mechanism for forming the flavor of soybean-flavor liquor is relatively less.This thesis mainly studied the dynamic changes of volatile flavors in wine and meat and microorganisms during the traditional dipping process,so as to explore the mechanism of the formation of soybean-flavor,and further study the different soaking time and different ratio of meat to wine to influence the main aroma components of soybean-flavor liquor,optimizing the traditional production process.The main conclusions were as follows:1.The dynamic changes of volatile flavor substances in wine during the process of immersion in aged meat were studied.The test results of the electronic nose and electronic tongue in soaking liquor showed that the basic wine was quite different from the dipped liquor sample,and the three wine samples with the soaking time of 4d,8 d,and 12 d were less different.The difference in the dipping time of 16 d,20 d,24 d and 28 d was small,but it was different from the first three.There were 129 volatile substances in the wine,including 38 esters,24 aromatic hydrocarbons,14 olefins,10 alcohols,10 alkanes,8 acids,7 aldehydes and 18 Other types of substances,and esters and aromatic hydrocarbons as the main volatile species.19 kinds of esters,18 kinds of aromatic hydrocarbons,3 kinds of aldehydes,3 kinds of alcohols,14 kinds of hydrocarbons and 4 kinds of other substances existed in the base wine,and the remaining substances were distributed in the soaking process.2.The dynamic changes of volatile flavor substances in the meat during the process of immersion in aged meat were studied.The extraction conditions of HS-SPME were optimized by single factor and orthogonal experiments.The results showed that the extraction effect was the best at 50 ?m/30 ?m DVB/CAR/PDMS extraction head,extraction temperature 80 °C,extraction time 50 min,and resolution time 9 min.Under the test conditions,there were 95 kinds of volatile flavor substances in the meat,of which 26 kinds of esters were the main flavor substances,12 kinds of alcohols,10 kinds of amines,9 kinds of olefins,and 7 kinds of aromatic hydrocarbons,6 kinds of aldehydes,6 kinds of ketones,6 kinds of acids and 13 kinds of other types.According to the distribution trend of different kinds of materials in different soaking time,there were three kinds of esters,one kind of acid,one kind of olefin,five kinds of amines and three other substances in the cooked meat without soaking.With soaking time increased,the variety of meat flavors also increased.3.The dynamic changes of microorganisms during the impregnating process of soybean-flavor liquor were studied.The quality of sequencing data of 16 S and ITS had been achieved.The number of bacterial OTUs in each sample ranged from 300 to700,and the total number of OTUs was 1,130,indicating that the bacterial species were abundant.The species were annotated and classified,and the overall abundance of each flora was observed as the soaking time increased.It had a downward trend and tends to be stable during the soaking time of 20-28 d.At the genus level,Lactobacillus and Bacteroides were the dominant bacteria in the process of infiltration,with an average abundance of 16.921% and 11.178%.At the species level,Lactobacillus and Bacteroides were the dominant bacteria,with an average abundance of 14.326% and 10.998%.The number of fungal OTUs in each sample ranged from 160 to 300,and the total number of OTUs was 777.As the soaking time increased,the fungal community became more and more abundant.At the genus level,the main dominant flora in the basic wine was Xeromyces,Pithoascus,Aspergillus and Mortierella,and Mortierella was dominant during the immersing process,with an average relative abundance of 8.773%;At the species level,Xeromyces was the advantage in the base wine.The relative abundance of the strain accounted for48.340%;during the immersing process,Cladosporium_delicatulum was dominant,and the average relative abundance reached 3.732%.Malassezia_restricta and Verticillium_leptobactrum followed,the average relative abundance was 3.051% and2.665%.4.The correlation between wine,meat and microbial flora during the process of immersion in aged meat was analyzed.There were 17 kinds of flavor substances in wine and meat.With the increase of soaking time of the meat,the flavor substances in the wine was decreased,and the flavor substances in the meat was increased.There was a strong correlation between the microbial flora and the flavor substances of wine and meat.The microbial flora was mainly negatively correlated with the flavor of the wine,but it was mainly positively correlated with the flavor of the meat.It wasindicated that the reason of wine flavor changes was not just the meat oxidation,adsorption and also microbial flora.5.The effects of different soaking time and different ratio of meat to wine on soybean-flavor liquor's main aroma components were studied.The soaking time and the ratio of meat to wine had a great influence on the main aroma components of soybean-flavor liquor.When the soaking time was 45 days and the ratio of meat to wine was 2:10,the concentration of the main aroma components was the lowest,but there was still a contribution to flavor.And the flavors and tastes of main aroma components were better,including ethyl acetate 187.915 mg/L,n-propanol 98.708mg/L,isobutanol 167.414 mg/L,ethyl lactate 355.046 mg/L,ethyl hexanoate 714.017mg/L,and ?-phenylethanol 90.217 mg/L. |
PDF Full Text Request