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.

Effects of Different Drying Methods on the Quality of Micronized Chinese Wolfberry Powder

[Objectives] To study the effects of different drying methods on quality of Chinese wolfberry powder. [Methods] The physical properties and nutritional contents of Chinese wolfberry powder prepared by hot air drying,vacuum freeze drying,microwave vacuum drying,drum drying and spray drying were measured and analyzed to explore the effects of different drying methods on quality characteristics of Chinese wolfberry powder. [Results] The total sugar content and reducing sugar contents of product: vacuum freeze drying > spray drying > microwave vacuum drying > drum drying > hot air drying; carotene and total flavonoid contents: vacuum freeze drying > microwave vacuum drying > spray drying > drum drying > hot air drying; after drying process,the dietary fiber content of product obtained by drum drying and spray drying was relatively higher,while the Vc content of Chinese wolfberry powder prepared by vacuum freeze drying was the highest. a~*value( redness to greenness) of color: vacuum freeze drying > microwave vacuum drying > spray drying > drum drying > hot air drying; the Chinese wolfberry powder prepared by vacuum freeze drying had the best solubility,hygroscopicity and rehydration ratio. [Conclusions] Microwave vacuum drying was the best method to prepare Chinese wolfberry powder,in order to keep its quality and consider the cost of production.

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.

Optimization of Fermentation Process of Carrot Juice by Probiotics and Analysis of Aroma Components

Carrot juice was fermented by probiotic Lactobacillus casei( CTCF-LC1) and Lactobacillus reuteri( CTCF-LT1) with sensory score as the main evaluation index,and the fermentation process was optimized by single factor and response surface experiments.The optimum ratio of fermentative strains CTCF-LC1∶ CTCF-LT1 was 1∶ 1,fermentation time was 8 h,inoculum size was 3.1% and fermentation temperature was26.6℃.Under the optimum conditions,the sensory score of fermented carrot juice was 91.3,pH was 4.50,total acid content was 3.73 g/L,total sugar content was 54.25 g/L,and reducing sugar content was 28.41 g/L.The carrot juice has bright orange color and stable state.It not only has the fresh flavor of fruit and vegetable juice,but also has the unique aroma from lactic acid bacteria fermentation,as well as soft and even taste,moderate acidity and sweetness.The changes of aroma components of carrot juice before and after fermentation were analyzed by headspace solid phase microextraction( HSPME) coupled with gas chromatography-mass spectrometry( GC-MS).After fermentation,substances with medicinal flavor components were reduced,and a lot of floral and fruit-scented substances were produced,such as methyl myristate,β-pinene,phenylethanol,and geraniol.Therefore,the results of this study can provide a theoretical basis for the development of fermented fruit and vegetable juice products with unique flavor substances.

Optimization of Acetic Acid Fermentation Process of Apple Cider Vinegar

This paper studied the fermentation rules of apple cider vinegar from fruit juice,to provide a theoretical guidance for the production of apple cider vinegar.Using Fuji apples as raw materials,the process parameters(fermentation temperature,fermentation time,stirring speed,and inoculation amount)of apple cider vinegar fermentation were optimized through single-factor experiments and response surface analysis.The results indicated that the fermentation temperature had no significant effect on the total acid content of apple cider vinegar fermentation,the fermentation time had an extremely significant effect on the total acid content of apple cider vinegar fermentation,and the stirring speed and inoculation amount had a significant effect on the total acid content of apple cider vinegar fermentation.Through process optimization,the optimal process parameters for apple cider vinegar fermentation are fermentation temperature of 33℃,fermentation time of 39 h,stirring speed of 1500 r/min,and acetic acid bacteria inoculation amount of 7%.Under such conditions,the total acid content of fermented apple cider vinegar is 62.22 g/L,very close to the predicted value of the model,indicating that the process parameters of acetic acid fermentation obtained by response surface methodology(RSM)optimization are reliable and can be used for actual production prediction.

Optimization of Technology for Increasing Total Ester Content of Jujube Wine by Adding Nutrients

Using jujube juice prepared from red jujube as raw material and Saccharomyces cerevisiae as experimental strain,the effect of nutrients on the content of total ester in jujube wine was studied. The nutrients affecting the total ester content of jujube wine were glutamine,arginine,calcium chloride and biotin by Plackett-Burman design. Through the steepest ascent test,it was determined that the central points of the optimum addition of nutrients were glutamine 40 mg/L,arginine 50 mg/L,calcium chloride 35 mg/L and biotin 0. 25 mg/L,respectively.Through Box-Behnken experiment design,taking glutamine,arginine,calcium chloride and biotin as experimental factors,and the content of total ester in jujube wine as response value,the response surface optimization experiment was carried out and the verification experiment was also carried out. It was found that the response surface model can be used to predict the total ester content of jujube wine when nutritional elements were added. When the content of total ester in jujube wine was the highest,the optimal combination of nutrients was glutamine38. 8 mg/L,arginine 53. 8 mg/L,calcium chloride 35. 7 mg/L and biotin 0. 3 mg/L. At this point,the content of total ester in jujube wine was 628 mg/L,which was very close to the predicted value. Through the sensory evaluation of jujube wine,it was found that adding nutrients could help to improve the taste of jujube wine,and the fermentation method of jujube wine by adding nutrients was simple and feasible.

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.

Effect of Magnetic Field Technology on Preservation Quality of Fresh-cut Apple

[Objectives]The paper was to study the effect of magnetic field technology on physicochemical properties of fresh-cut apple during storage.[Methods]Using fresh-cut apples as materials,magnetic field assisted refrigeration and conventional refrigeration control groups were set up,and the preservation effects of magnetic field assisted refrigeration on fresh-cut apples were tested by measuring the changes of microorganisms and physicochemical indicators.In this experiment,the conditions of magnetic field assisted refrigeration group was set as follows:temperature 4℃,magnetic field intensity 5 mT,static magnetic field,and storage for 6 d.[Results]At 6 d post storage,the weight loss rate,total number of colonies and total number of fungi of fresh-cut apples increased;the L value and hardness showed a downward trend;the soluble solid content first increased and then decreased;and the total acid decreased first and then increased.The above indicators in magnetic field assisted refrigeration group changed more gently than that in conventional refrigeration group.Compared with conventional assisted refrigeration,the weight loss rate of fresh-cut apples treated by magnetic field combined with 4℃refrigeration was reduced by 68.00%;the hardness was increased by 12.23%;the total number of colonies and total number of fungi were reduced by 64.15%and 37.50%;and the L value did not change much.High content of soluble solids and total acid was maintained.[Conclusions]Magnetic field assisted refrigeration delays quality deterioration of fresh-cut apples during storage,prolongs shelf life,and further improves their edible quality and commodity value.

Influence on the aroma substances and functional ingredients of apple juice by lactic acid bacteria fermentation

This study aimed to analyze the influence of lactic acid bacteria fermentation on the aroma composition and functional composition of apple juice,selected Lactobacillus reuteri to ferment apple juice,used HS-SPME-GC-MS and HPLC to analyze the changes of volatile aroma composition,organic acids and phenols after fermentation.The results showed the best fermentation time was about 18 h;The type and content of volatile substances(mainly alcohols and esters)in fermented juice changed and affected the overall aroma;The content of organic acids such as succinic acid,tartaric acid,malic acid and pyruvic acid affected the taste and flavor;The content of polyphenols such as gallic acid and protocatechuic acid increased,which enhanced the antioxidant capacity and functionality of fermented juice.This result showed the positive effect of fermentation on juice and provided a reference for the subsequent research on the aroma and functional composition of apple juice.