Preparation Of New Tobacco Flavors And Spices By Fermenting Sweet Corn With Yeast

Cigarettes,as the main product of the tobacco industry,have become one of the important consumer products in people's lives.However,with the implementation of the national coke reduction and harm reduction project,cigarettes due to the reduction of tar amount have caused problems such as insufficient flavor.The addition of tobacco flavors and fragrances can effectively solve this problem.There are two main sources of tobacco flavors and fragrances,namely natural flavors and synthetic flavors.Both have certain deficiencies.Natural fragrances are expensive and have low yields,which damages natural resources;synthetic fragrances have a single fragrance and are subject to reaction conditions.So people began to use biotechnology methods to synthesize tobacco flavors and fragrances.The use of aromatic compounds in the fermentation products to improve the quality of tobacco leaves,enrich the source of tobacco flavors and fragrances,and enhance the competitiveness of enterprises.Sweet corn is widely cultivated in China,which is rich in carbohydrates and has a sweet and special smell.It can be used as a raw material for the production of tobacco flavors and spices by microbial fermentation.There are few reports in this regard.In this study,sweet corn was used as the fermentation raw material,using yeast isolated from the soil of a tobacco planting base in Guangxi,as well as the purchased Angel fruit yeast and the laboratory-engineered engineering bacteria Pichia PGII.The method was optimized to screen out the better fermentation products and add them to cigarettes to evaluate their effects.The results obtained are as follows:Multiple strains of yeast were isolated from the soil of a tobacco planting base in Guangxi.After morphological observation and molecular identification,535 was Wickerhamomyces anomalus yeast and 536 was Saccharomyces cerevisiae.In the later period,the two strains were compared with commercial Angel fruit yeast and Pichia PGII in physiological and biochemical aspects.Results showed that Angel fruit yeast was superior to other strains in growth state and alcohol tolerance,reflecting a major advantage of commercial strains over wild strains.Pichia PGII not only has the slowest growth rate,but also basically does not grow at 8%,10% and 12% alcohol concentration.In terms of hydrolytic enzymes,535 Wickerhamomyces anomalus yeast performed best in pectinase and amylase activities,and none of the four yeasts had the ability to hydrolyze cellulose.Subsequently,100 g of sweet corn was squeezed into corn syrup and cooked and used as fermentation medium to inoculate the bacterial solution.The inoculation amount,water addition amount andfermentation time were set as single factors,and the optimal single factor level was obtained with the content of water-soluble amino acids as indicators.The optimal fermentation conditions for 535 Wickerhamomyces anomalus yeast are: 1% inoculation volume,25%water addition,and fermentation for 24 h;536 Saccharomyces cerevisiae optimal fermentation conditions are: 0.5% inoculation volume,50%water addition,and fermentation for 24 h;Angel fruit yeast The optimal fermentation conditions are: 1% inoculation volume,25% water addition,and fermentation for 24 hours;while the optimal fermentation conditions for Pichia PGII are: 0.5% inoculation volume,50% water addition,and fermentation for 24 hours.By measuring the content of reducing sugars and total sugars,it can be concluded that the fermentation reaction of 535 Wickerhamomyces anomalus yeast is easily restricted by the amount of water added,and Pichia PGII has the worst hydrolysis capacity of total sugars among the four strains,which is not conducive to The fermentation reaction proceeds.Taking the optimal level of single factor as the central point,considering the influence of interaction,a three-factor and three-level test group was designed using the combination of centers.Using amino acid content as the only response value,the experimental results obtained by Design Expert 8.0 constructed a response surface model to obtain the fitted quadratic polynomial equation and the best fermentation parameters.The results show that the optimal fermentation parameters of 535 Wickerhamomyces anomalus yeast are inoculation volume,water addition and fermentation time respectively 0.83%,27.25% and 24.94 h;36Saccharomyces cerevisiae optimal fermentation parameters are inoculation amount,water addition and fermentation time respectively0.33%,53.25% and 24.6 h;the optimal fermentation parameters of Angel fruit yeast are inoculation volume,water addition and fermentation time respectively 1.055%,21.75% and 25.32 h;and the optimal fermentation parameter of Pichia PGII is inoculation the amount,amount of water added,and fermentation time were 0.21%,49.75% and 26.16 h,respectively.Under the optimal fermentation conditions,the measured water-soluble amino acid contents were 52.97 mg / m L,45.09 mg / m L,53.41 mg / m L,and 43.17 mg / m L,which were in line with the model expectations.Due to the shortcomings of Pichia PGII in terms of physiology and biochemistry,the products obtained after fermentation of 535 Wickerhamomyces anomalus yeast,536 Saccharomyces cerevisiae and Angel fruit yeast with sweet corn under their optimal conditions were selected for GC-MS detection.As a result,it was found that 535 Wickerhamomyces anomalus yeast,536 Saccharomyces cerevisiae,and Angel fruit yeast contained 20,23,and 14 volatile compounds,respectively.The relative content of5-hydroxymethyl-2-furancarboxaldehyde,3-oxopropyl butyrate,D-glycerol-1-glucoheptose and lactose in 535 fermentation products is higher;glycerin,5-hydroxymethyl-2-furan formaldehyde,D-glucuronolactone,and sorbitol are relatively high in 536 fermentation products;2-(2-Butoxyethoxy)ethyl thiocyanate,D-mannose,3-deoxy-D-mannoselactone,?-D-glucoheptonic?-lactone,2,3-dihydro-3,5dihydroxy-6-methyl-4hydro-pyran-4-one in Angel fruit yeast fermentation products account for a relatively high proportion.Finally,three kinds of fermentation products were added to tobacco to make cigarettes,which were labeled as experimental group 1,experimental group 2 and experimental group 3,and were smoked by professionals.Compared with the unfilled cigarettes,the smoke of the experimental group 1 and 2 cigarettes did not improve significantly,with greater irritation and insufficient fragrance.The smoke of the three cigarettes in the experimental group has been significantly improved,the smoke is soft,less irritating,and the aroma is more sufficient.In summary,the addition of the product obtained after the fermentation of sweet corn by Angel fruit yeast to cigarettes can effectively improve the problems of strong smoke irritation and insufficient flavor,and has the potential to be used as an tobacco flavor and fragrance in industrial production.And its amino acid content is the highest,indicating that the method of identifying amino acid content as astandard for identifying tobacco flavors and fragrances is feasible.This research provides a theoretical basis for developing new biological flavors and enhancing the status of cigarette products,and at the same time enriches the sources of flavors and flavors for tobacco.