Abstract
The solubility of persimmon tannins during six treatments for removing astringency was compared using HCL in methanol at different concentrations and temperatures. We also examined the relationships between the solubilities and the concentration of acetaldehyde in the flesh. The six treatments were : a) acetaldehyde vapor, b) carbon dioxide gas, c) ethanol vapor on intact fruit, d) ethanol vapor on postharvest fruit, e) peeled fruit for sun drying, and f) freezing and thawing. Treatments of fruits with acetaldehyde vapor, postharvest treatment with ethanol vapor, and freezing and thawing gave tannins with low, intermediate, and high solubility, respectively. The solubility of tannins decreased with time after the removal of astringency ; the residual tannins was highest in fruits with high acetaldehyde concentrations.
