Study On Pineapple Vinegar

Choosing Pineapple as raw material, pineapple vinegar was prepared, by alcoholic fermentation and acetic acid fermentation. Alcohol fermentation conditions, acetic acid fermentation conditions, clarification and sterilization methods of pineapple vinegar, and aromatic ingredients, and so on were studied, and the results are as follows:(1)The screening test of optimum yeast for pineapple alcohol fermentationSelecting the degree of alcohol and aroma as the main indicators, the optimal strains for pineapple alcohol fermentation were screened from Angel Yeast, EC1118, D245, A1B11, A4C13 and D1B2. The results showed that:Angel Yeast was the most suitable strains. After fermentation, the degree of alcohol reached 5.9%(V/V), with good aroma.(2) The test of pineapple alcohol fermentationSingle-factor test fixed the optimum conditions for pineapple alcohol fermentation, which were:initial sugar content 16°Brix, inoculums 2%, temperature 28℃,pH3.18.(3)The screening test of the optimal bacteria for pineapple acetic acid fermentationChoosing the total acid content as the main indicator, the acetic acid bacteria strains were screened from Section AS 1.41, Shanghai wine 1.01, GIM1.158 for pineapple acetic acid fermentation, the results showed that:acetic acid bacteria-Section AS 1.41 was the optimum. The maximum total acid content after fermentation reached 3.56 g/100mL; the highest acid production was 0.247 g/L·h; the highest acid transfer rate was 55.86%.(4) The test of pineapple acetic acid fermentationBy the single factor test and orthogonal test, the optimum conditions for pineapple acetic acid fermentation were:initial alcohol content 7%(V/V), temperature 33℃, inoculums10%, rotation speed 160rpm, medium volume 50mL (250mL flask).(5)The test of pineapple vinegar clarifying agent’s choiceChoosing the clarify degree as the main indicator, the best clarifier was selected from gelatin, agar, diatomite, chitosan, PVPP, the results showed that:agar was the best pineapple vinegar clarifying agent. When the agar content added to 0.20g/L, the light transmission rate reached 98.2%, and had no significant effect to the total acid, total esters, Vc content and other important indicators in the vinegar.(6) The test of pineapple vinegar’s sterilization methodChoosing the the total acid content, Vc content, and microbial indicators in pineapple vinegarafter sterilizing as the main indicators, the best sterilization methods were selected from 65℃30min,85℃15min and 95℃30s three pasteurization ways, the results showed that 95℃30s was the best sterilization process for pineapple vinegar.(7) GC-MS analysis of aroma components of pineapple vinegarMass information which obtained according to GC-MS mass spectrometry searched from computer database.21 compounds were identified, including 7 esters, 3acids,4 alcohols,2 aldehydes,1phenols and 4 remaining heterocyclic compound.