Application of Molecular Marker Technology in the Study of Forest Tree Species

Due to its unique advantages, molecular marker technology is widely applied in the research of forest tree species. This paper reviewed the application of molecular marker technology in tree species resource diversity, germplasm identification, genetic map construction, gene mapping and marker-assisted selection (MAS) breeding. In addition, it elaborated the great significance of molecular marker technology to promote the sustainable development of forestry production in China.

Effects of Different Sterilization Conditions on Active Components and Flavor of Apple Vinegar

[Objectives]To explore the effects of different sterilization conditions on nutrition and flavor of apple vinegar.[Methods]Five kinds of high temperature short time(HTST)sterilization conditions were selected to treat apple vinegar,and the volatile aroma components and the content of active components in apple vinegar before and after sterilization were analyzed.[Results]Compared with the control,the contents of total acid and malic acid in the samples after sterilization changed little,but the contents of citric acid increased significantly(P<0.01),and the contents of total phenols,ascorbic acid and total flavonoids decreased.Ethyl acetate,isopentyl acetate,ethyl caprylate,phenethyl acetate,1-pentanol,phenylethyl alcohol,acetic acid,and sec-butyl ether were the characteristic aroma components which contributed to the flavor of apple vinegar.As sterilization temperature increased,the content of esters decreased,while the content of acids,alcohols and aldehydes increased.The contents of nutrition,active components and volatile aroma components in apple vinegar under 100℃and 30 s sterilization conditions had little change compared with other sterilization conditions,so 100℃and 30 s were the optimal sterilization conditions.[Conclusions]Under different sterilization conditions,the content of flavor components in apple vinegar will change greatly,which will affect the quality of apple vinegar.

Study on Brewing Technology of Pear Wine

[Objectives]The quality of pear wine is directly affected by parameter control in the production process, especially in the fermentation stage. The fermentation parameters of pear wine were controlled by studying the effects of fermentation parameters on the product, in order to optimize the fermentation parameters. [Methods]The fermentation conditions of pear wine were optimized by single factor experiments and an orthogonal experiment. [Results] The optimum fermentation conditions of pear wine were nitrogen source 1.0 g/L, fermentation temperature 20 ℃, and pH of fermentation liquid 4.3. The pear wine brewed was full, mellow and harmonious, and had a unique style. The ethanol content of the pear wine was 12.33 through physical and chemical analysis. [Conclusions] This study provides theoretical basis and technical support for the industrial production and promotion of pear wine.

Comparative Study on Functional Properties of Mulberry Black Tea Fermented by Phellinus igniarius and Eurotium cristatum

[Objectives]To compare functional properties of mulberry black tea fermented by Phellinus igniarius and Eurotium cristatum.[Methods]The functional components of mulberry black tea fermented by P.igniarius and E.cristatum,the deep processing and health care effects of two probiotic fungi were explored.[Results]The polysaccharide content in the tea fermented by P.igniarius was the highest at 0.410 mg/mL,and the hydroxyl radical scavenging rate was the strongest,reaching 60.31%;the content of flavonoids in the tea fermented by E.cristatum was the highest,reaching 60.65μg/mL,and the content of polysaccharides was 83.17%higher than that of mulberry black tea,reaching 0.279 mg/mL.[Conclusions]The mulberry black tea fermented by P.igniarius and E.cristatum has improved in different functional components,and has its own advantages in aroma and mouthfeel,so it has certain research value and market prospect.

Application of Metabonomics in the Research of Lactic Acid Bacteria-fermented Foods

Lactic acid bacteria have been important industrial floras in the food fermentation production industry since ancient times.Their metabonomics technology has been widely used in the process monitoring,product classification and flavor formation mechanism of lactic acid bacteria-fermented foods.In this study,we discussed the application status of metabonomics technology in lactic acid bacteria-fermented food industry and scientific research,including dairy products,soy products,beverages and some pickled foods.Metabolomics will be applied in the research fields of lactic acid bacteria metabolism mechanism of lactic acid bacteria-fermented foods,lactic acid bacteria metabolomics database construction and expansion,metabolomics and genomics,and proteomics.In particular,the metabolomics technology will be introduced into product development and quality monitoring of traditional Chinese lactic acid bacteria-fermented foods,such as fermented bean curd and suancai,thereby perfecting industry norms and improving the level of industry development.

Application of Transcriptomics in the Analysis of Community Structure of Food Fermented with Lactic Acid Bacteria

Revealing the structural characteristics,succession changes and functional genes of the microbial community in lactic acid bacteria-fermented food has been the focus of scientific research and industrial production for many years.In recent years,high-throughput sequencing technology has become an important tool for the research of lactic acid bacteria-fermented food microorganisms due to its advantages of high efficiency and being relatively cheap.In this paper,starting from the research on the genome,transcriptome and metabonomic levels of high-throughput sequencing technology,we reviewed the progress of transcriptomics in the study on microbial community structure,interaction,and functional gene mining of lactic acid bacteria-fermented food,and analyzed and discussed the main problems and development trends it faces,providing a certain reference for the scientific research and industrial production of fermented food in the future.

Screening and Properties of Functional Probiotics for Apple Fermentation

[Objectives]To screen functional probiotics for apple fermentation and study their probiotic properties.[Methods]A total of 35 strains were screened from traditional fermented foods in different regions.After primary screening,re-screening and research on growth characteristics,two characteristic strains,CTCF-LC1(LC1,with strong acid production ability)and CTCF-LT1(LT1,with strong adaptability),were obtained.[Results]The results of physiological and biochemical identification and 16S DNA-based identification show that LC1 is Lactobacillus casei and LT1 is Lactobacillus reuteri.Their fermentation performance in apple juice was tested,and it was found that the two strains grew well in the fermentation broth,and the total number of colonies could reach 10^(9) cfu/mL.The final pH value of LC1 fermentation broth dropped below 3.5,and the total acid content exceeded 12 g/L.The pH of LT1 fermentation broth dropped to 3.9,and the total acid content also exceeded 6 g/L.In the study on the antioxidation property of apple juice,it was found that after high temperature and high pressure steam sterilization,the DPPH free radical scavenging rate of apple juice extract increased by 35.8%,and potassium ferricyanide reduction capability increased by 68%.After fermentation by LC1 and LT1,the potassium ferricyanide reducing power of apple juice was increased by 42.9%.[Conclusions]This has a good application prospect in the development of fruit and vegetable juice fermented beverages.