• Food Science and Preservation
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• v.6 no.2
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• pp.228-232
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• 1999

Total acidities were incereased gradually during fermentation. Total acidities of vinegars which fermented from sweet and astringent persimmon were 5.95 and 5.81% at 8th day of acetic acid fermentation, respectively. Hunter's color values were not significant difference during alcohol fermentation and acetic acid fermentation. Browning incereased continuously during alcohol fermentation whereas browning and turbidity decreased continuously during acetic acid fermentation. The browning and turbidity of vinegar which fermented from sweet persimmon was higher than those of vinegar which fermented from astringent persimmon. The contents of total tannin were 2.40 and 6.44mg/ml at the initial fermentation of sweet and astringent persimmon respectively. But in contents decreased continuously during fermentation. Reducing and total sugar contents decreased continuously during fermentation. At 5th day of acetic acid fermentation, contents of reducing and total sugar were 5.0 and 8.5mg/ml in sweet persimmon and 2.8 and 2.9mg/ml in astringent persimmon respectively.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1203-1208
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• 1998

To utilize astringent persimmon (Diospyros kaki, T.) effectively, response surface methodology (RSM) was applied to optimize and monitor the vinegar fermentation conditions by two stage fermentation. In the first stage, the fermentation conditions for maximum alcohol content was $20.51\;^{\circ}brix$ in sugar concentration of astringent persimmon, 139.52 rpm in agitation rate, and 94.88 hr in fermentation time. When sugar concentration of astringent persimmon was $14\;^{\circ}brix$, maximum alcohol content predicted by response surface methodology was 7.1% at agitation rate of 40 rpm and fermentation time of 120 hr. In the second stage, the fermentation conditions for maximum acidity was 224.40 rpm in agitation rate, 176.07 hr in fermentation time. Alcohol content and acidity predicted at the optimum conditions were similar to experimental values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.277-282
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• 2001

The effects of chitosans with two different molecular weights (150 and 37 kDa) on the clarification of persimmon vinegar were investigated. The coagulated solids increased with increasing chitosan concentrations. Chitosan treatment had no effect on pH and acidity. Turbidity, browning, contents of tannin and soluble solids decreased with increasing chitosan concentrations. An increase in chitosan concentration resulted in an increase in color L* value and a decrease in a* and b* values. Reduction in turbidity and tannin contents somewhat differed depending on the molecular weights of chitosan. In sensory evaluation, chitosan treatment did not affect color and flavor over all concentrations tested. However, astringent taste was noticeably strong by treatment with 500mg/L chitosan, resulting in low overall acceptability. Therefore, the most effective clarification of persimmon vinegar was achieved by treatment with 400mg/L chitosan, irrespective of molecular weight.

• Food Science and Preservation
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• v.6 no.2
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• pp.233-238
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• 1999

This study was determined changes of components of sweet and astringent persimmon vinegars by two stages fermentation. Free sugars of persimmon juices before alcohol fermentation were mainly composed of glucose, fructose and sucrose. The content of glucose, fructose and sucrose of sweet persimmon juice was 6.60, 6.12 and 1.74%, respectively, and those of astringent persimmon was 5.63, 5.21, 0.62%, respectively. The contents of free sugar decreased continuously during fermentation. Major organic acids of persimmon juices were acetic, galacturonic, malic, citric and ascorbic acid. Alcohols of persimmon juices was detected methanol, ethanol, iso-propylalcohol, n-propylalcohol and iso-butylalcohol at the initial fermentation. The contents of alcohols increased continuously up to 4days of fermentation but their contents except ethanol decreased slightly at 5th day of fermentation. Contents of free amino acid were higher in sweet persimmon than those in astringent persimmon. Volatile components increased during acetic acid fermentation.