| Garlic is a medicinal and edible dual-use resource.In addition to having a good therapeutic effect,it is also an important seasoning and is widely used.However,garlic has strong seasonality,short storage period,and the garlic is spicy and has a special smell,which is difficult for some people to accept.Therefore,sugar garlic,laba garlic,dehydrated garlic powder,and garlic puree prepared by deep processing are very popular.Recently garlic Research hotspots of deep-processed products include fermented black garlic.These deep-processed garlic products have expanded the garlic industrial chain and enriched the processing and utilization of garlic.Considering that garlic is an important kitchen seasoning raw material,we plan to use garlic as the raw material,and systematically study the key processes and related quality characteristics of garlic and vinegar brewing by optimizing processes such as enzymolysis,yeast growth experiments,alcohol fermentation and acetic acid fermentation.The preparation of fermented garlic vinegar with the flavor of both garlic and vinegar provides new ideas for the deep processing and utilization of garlic.The main findings are as follows:(1)Enzymatic hydrolysis process of garlic juice: Using Wushan purple red sky garlic as raw material,the effects of factors such as the amount of pectinase and cellulase,the p H of the hydrolysis,the temperature of the hydrolysis and the time of the hydrolysis on the hydrolysis of garlic were investigated.Through the single factor test and orthogonal test,it was determined that the added amounts of pectinase and cellulase were 0.2%(w/w)and 0.1%(w/w),the enzymatic hydrolysis was p H4.0,and the enzymatic hydrolysis at 40°C for 2.5h Under these conditions,garlic juice with a yield of(82.3±0.71)% and a reducing sugar content of(4.35±0.05)mg/m L was obtained.After enzymolysis,the juice yield and reducing sugar content of garlic juice were increased,which provided basic conditions for the production of garlic wine vinegar.(2)Yeast growth test: In order to reduce the bacteriostatic properties of garlic juice and meet the growth needs of yeast in alcohol fermentation,the garlic juice after enzymatic hydrolysis was treated at high temperature,and the yeast culture medium was added for growth test.The optimized process conditions for high temperature treatment of garlic juice are: the processing temperature is 90°C,the processing time is 40 min,and the material-liquid ratio is 1:6.The number of yeast colonies on the yeast culture medium and the allicin content of the garlic juice after high temperature treatment are respectively It was(170±2.0)cfu,(0.060±0.26)mmol/g.This treatment condition can effectively reduce the bacteriostasis of garlic juice,ensure the normal growth of yeast and retain the flavor of garlic juice,and provide conditions for subsequent alcohol fermentation.(3)Garlic juice alcohol fermentation process: Four types of yeasts(RW,GJ,SY,BV)are selected,and the indicators of alcohol content and total ester content after fermentation are selected.BV is selected as the best yeast for garlic alcohol fermentation.It is determined that the alcohol fermentation time is 96 h according to the change of the alcohol content with the fermentation time.Considering the reduction of nutrients in the diluted garlic juice,6%(w/w)potato was added as a nitrogen source to assist alcohol fermentation.Taking the alcohol content,total acid,total ester,etc.of the fermentation broth as evaluation indicators,taking yeast inoculation amount,initial sugar content,fermentation temperature,and initial p H as factors to be examined,the range of each factor was determined through a single factor test,and the initial sugar content was determined to be 14%.The response surface optimization test was performed on the basis of%,and the optimal conditions for alcoholic fermentation were determined using the alcohol content and total ester content as the response values.The fermentation temperature was 24 °C,the yeast inoculum amount was 0.10%,and the fermentation p H was 4.50.It was 10.1% and the total ester content was 1.502 g/L of garlic vinegar acetate.(4)Acetic acid fermentation and clarification process: The garlic wine obtained from the best alcohol fermentation process is used for acetic acid fermentation.The test takes the total acid and amino acid nitrogen of the fermentation broth as the main evaluation indicators and combines sensory evaluation to determine the range of factors such as the alcohol content of the fermentation broth,the inoculum of acetic acid bacteria,the fermentation temperature,and the speed of the shaker;And total esters are the response values.The optimal conditions for the acetic acid fermentation process were determined by response surface optimization.The fermentation temperature was 32 °C,the amount of acetic acid bacteria was 10%,and the speed was 110 r/min.The total acid was 5.25 g/L and the total ester was 5.32 g/L of garlic vinegar V.Comparing the clarification effects of chitosan,diatomaceous earth,CMC,bentonite and gelatin on garlic vinegar,the results show that chitosan has the best clarification effect on garlic vinegar.Garlic vinegar is added at 1.0 g/L The light transmittance T reaches 89.40%.Analysis of the low acetic acid content of garlic fermentation vinegar may be related to three factors: one is the peroxidation reaction during the fermentation process;the other is the fermentation performance of the bacteria;the third is the bacteriostatic properties of garlic itself.(5)Garlic vinegar beverage and garlic sweet vinegar product preparation test: Using fermented garlic vinegar as the raw material,based on the relevant standards for the range of acetic acid content in vinegar,and using fuzzy sensory evaluation methods to optimize the best garlic vinegar drink V1 and garlic sweet vinegar V2 The best formulation ratio,garlic beverage vinegar formulation: 0.6% citric acid,2.0% white sugar,97.4% raw garlic vinegar;sweet garlic vinegar: 34% commercially available Hengshun 9° rice vinegar,The amount of raw garlic vinegar was 66%.(6)Analysis of quality characteristics of garlic vinegar products and establishment of quality standards.The original garlic vinegar,garlic vinegar drink and garlic sweet vinegar were analyzed and compared for quality characteristics and established quality standards.In terms of basic physical and chemical indicators: the content of reducing sugar in raw garlic vinegar and garlic vinegar beverages reached 0.717 mg/m L and 0.226 mg/m L,the taste of vinegar was moderately sweet and sour,and the total acid content of garlic sweet vinegar was 3.310 g/100 m L,which can be used as seasoning vinegar.The total thiosulfinate of garlic's characteristic substance still reached 0.055mmol/g after fermentation.Organic acids: The organic acid analysis of garlic vinegar products found that the taste intensity of each organic acid in the original garlic vinegar TAV accounted for the total acidity intensity ratio of lactic acid(56.08%),acetic acid(34.13%),and succinic acid(6.93%),Citric acid(1.78%),malic acid(0.67%),tartaric acid(0.28%),oxalic acid(0.13%).The main organic acids of garlic raw vinegar are lactic acid and acetic acid,which contribute the most to the flavor of garlic vinegar.In terms of volatile flavor substances: The volatile flavor substances in garlic vinegar products and fresh garlic were separated and identified using HS-SPME-GC-MS.The volatile flavor substances in raw garlic vinegar,garlic vinegar beverage,and garlic sweet vinegar were 81 and 73,respectively,45 kinds,esters,acids,alcohols and sulfides are important substances that affect the flavor of garlic vinegar products.Among them,there are 7,8,and 8 kinds of characteristic flavor substances,and acetic acid is the characteristic flavor substance of raw garlic vinegar.Isoamyl ester,ethyl n-hexanoate,ethyl octanoate,phenylethanol,hexyl acetate,ethyl 2-methylbutanoate,n-hexanol.According to the cross-section analysis of the characteristic flavor substances of garlic vinegar products,it is known that brandy and melons are the main characteristic flavors of garlic vinegar.At the same time,they are supplemented by honey and sweet flavors,which constitute the unique flavor characteristics of garlic vinegar.There are 17 kinds of rare and volatile components in garlic vinegar products.Although the main flavor of garlic vinegar cannot be determined,it still contributes to the overall flavor of garlic vinegar.Analysis of volatile sulfur compounds shows that 19 kinds of sulfur compounds were detected in fresh garlic,the highest content of which is diallyl trisulfide.The types and contents of sulfur compounds in garlic vinegar after fermentation have changed greatly.Sulfur compounds in raw garlic vinegar were reduced to 11 kinds.After fermentation,high temperature,dilution and microbial action during fermentation,unstable sulfur compounds were degraded and volatilized,but 3,4-dimethylthiophene and sulfurized propylene The content increases after fermentation,giving the garlic a unique light garlic aroma.Sensory quality of garlic vinegar beverage: light yellow and shiny;suitable sweet and sour,full and mellow;garlic vinegar harmonious,no bad smell;the product is uniform and clear,no impurities visible to the naked eye.Physical and chemical indicators: total acid(calculated as acetic acid)5.25 g/L,soluble solids 8.2%.The total number of bacteria was <30 cfu/m L,and coliform bacteria and pathogenic bacteria were not detected.The indicators of the garlic vinegar beverage prepared in this test meet the requirements of NYT 2987-2016 “Green Food Fruit Vinegar Beverage” and SBT10337-2012 “Preparation of Vinegar Vinegar” standards and can be used as a vinegar beverage in the fruit and vegetable vinegar industry.Sensory quality of garlic sweet vinegar: light yellow and shiny;suitable sweet and sour,full and mellow;garlic vinegar harmonious,no bad smell;the product is uniform and clear,no visible impurities.Physical and chemical indicators: total acid(calculated as acetic acid)33.1 g/L,soluble solids 7.3% The total number of bacteria was <20 cfu/m L,and coliform bacteria and pathogenic bacteria were not detected.The indicators of the sweet garlic vinegar prepared in this test meet the requirements of SBT10337-2012 "Prepared Vinegar" and GB2719-2003 "Vinegar Hygienic Standard" and can be used as a seasoning vinegar in the seasoning industry. |
PDF Full Text Request