Development Of Roxburgh Rose(Rosa Roxburghii Tratt) Fruit Vinegar Beverage And Its Quality Change During Fermentation

The processing of roxburgh rose has shown a trend of diversification In recent years,The product lacks technology,and no improvement in taste,which is an important reason to restrict its industrial development.The processing of roxburgh rose into brewing vinegar can significantly improve the bitterness and astringency of the rosin juice itself.The vinegar vinegar has good nutrition and health functions and has a promising market prospect.This paper clarifies the changes of nutrient composition and flavor during the acetic acid fermentation of roxburgh rose vinegar by optimizing the process of ethanol fermentation of vinegar and acetic acid fermentation.A more in-depth systematic study led to the following conclusions:(1)Based on the single factor test,the four factors of yeast inoculum ?fermentation temperature?initial sugar content and fermentation time were selected,and the processing technology of the roxburgh rose vinegar beverage was studied through orthogonal design and range analysis.Its process parameters have been optimized.The experimental results showed that when the initial sugar content was20%,the yeast inoculation was 11%,the initial fermentation temperature was 30?,and the fermentation time was 9 days,the alcohol accumulation of the juice was optimal during the alcohol fermentation stage.The biggest factor influencing the accumulation of alcohol is the initial sugar content,followed by the fermentation time,yeast inoculum,fermentation temperature.(2)Based on the single factor experiment,the three factors of fermentation temperature ? initial alcohol content and inoculum size were selected.Through orthogonal design and range analysis,the accumulation of acetic acid during the acetic acid fermentation of roxburgh rose vinegar was discussed.The clarification technology in the processing of fruit vinegar beverages,and its process parameters were optimized.The results showed that the initial alcoholicity was 6.4%,and the addition of acetic acid bacteria was 6%.When the fermentation temperature was 30?,the accumulation of acetic acid was the best and no bad odor was produced.The biggest factors affecting the accumulation of acetic acid are the initial alcohol content,the second fermentation temperature,and the acetic acid bacteria inoculation amount.When the amount of gelatin added was 0.06%,the clarity of the pear fruit vinegar beverage was the best,and the light transmittance of the vinegar liquid was 95.50%.(3)Using the modern analysis technology of gas chromatography-mass spectrometry,the changes of volatile components in the acetic acid fermentation and fruit vinegar aging process were analyzed.After the completion of acetic acid fermentation,there are 12 groups of isoamyl acetate ? ethyl n-hexanoate ? ethyl octanoate?ethyl decanoate?ethanol?isoamyl alcohol?2-heptanol?phenylethyl alcohol?acetic acid?caprylic acid?decanoic acid and furfural.The fraction still remains in the pear vinegar,where the content of esters is higher than the other volatile components produced in the fermentation,but lower than the content of esters in the initial wine;from the first day of fermentation to the end of the fermentation,the ester Substances generally show an upward trend.From the time of fermentation to the second day of fermentation,The relative content of acids has been increasing,but it has declined during the late fermentation.Throughout the fermentation process,the relative content of volatile substances in alcohols and ketones did not change much.Three months after the aging of the vinegar vinegar,the type of esters changed significantly compared with the end of the acetic acid fermentation.During the aging process,isobutyl acetate?benzyl acetate?ethyl phthalate and phenylamperate were produced.Ethyl Acetate?Ethyl 3-hydroxyoctanoate?Ethyl Laurate?Ethyl Myristate?Ethyl Oleate?etc.while Alcohols and Acids Increased category.(4)The effect of acetic acid fermentation time on the type and content of organic acids in vinegar was studied using high-performance liquid chromatography.The results showed that the contents of four organic acids such as malic acid,ascorbic acid,lactic acid,and acetic acid increased during the acetic acid fermentation within 1-4days of citric acid fermentation.The greatest change was in ascorbic acid,followed bylactic acid.The content of ascorbic acid in the pear fruit vinegar is second only to acetic acid,which is obviously higher than that of other organic acid components.The highest malic acid content was 98.13?g/mL,the highest ascorbic acid content was731.48?g/mL,the highest lactic acid content was 81.80?g/mL,the highest acetic acid content was 1079.57?g/mL,and the total acidity reached the highest at the end of the fermentation.