Studies on the Mechanism of the Removal of Astringency in Japanese Persimmons (Diospyros Kaki L.) (II) Varietal difference of acetaldehyde contents, ethanol contents and alcholdehydrogenase activities of kaki fruits

• Published in: NIPPON SHOKUHIN KOGYO GAKKAISHI Vol. 20; no. 11; pp. 529 - 536
• Main Author: NAKAMURA, REINOSUKE
• Format: Journal Article
• Language: English
• Published: Japanese Society for Food Science and Technology 15.11.1973
• ISSN: 0029-0394
• DOI: 10.3136/nskkk1962.20.529

Employing 23 varieties of kaki, 8 of non-astringent variety, 11 of astringent variety and 4 of variant variety, the varietal differences of changes of acetaldehyde contents, ethanol contents and alcoholdehydrogenase activities in the flesh of kaki fruits, followed with the removal of astringency, were studied. The acetaldehyde contents of non-astringent fruits were nearly ten times as much as astringent one. In the astringent varieties, the acetaldehyde contents increased suddenly to the similar extent of non-astringent one in the course of the artificial removal of astringency by the treatment of ethanol or carbon dioxide, in proportion to the ethanol contents of the flesh of fruits. Alcoholdehydrogenase activities were almost not different between astringent and nonastringent varieties, and also not accompanied with either the acetaldehyde contents or the ethanol contents of the flesh of fruits. The acetaldehyde contents of astringent varieties after the artificial removal of astringency by the treatment of carbon dioxide were much as compared with the artificial removal of astringency by the treatment of ethanol. On the basis of these results, some mechanism of the acetaldehyde formation in the flesh of kaki fruits were discussed.