Seasonal changes in the concentration of ethanol and acetaldehyde of satsuma mandarin (Citrus unshiu Marc.) fruit were examined to determine whether these components afford an additional measure of maturity to the Brix-acid and total sugar-acid ratio.
Samples of ‘Okitsu Wase’, an early maturing cultivar, and ‘Silverhill’, a common cultivar, were harvested at intervals of approximately 15 days from September 3, 1973 to January 28, 1974.
The concentration of ethanol and acetaldehyde in the juice and peel of both cultivars increased gradually during maturation; ethanol increased from 9.74 to 19.92 mg and from 8.15 to 18.43mg per 100ml of juice in the early maturing and common cultivars respectively, while acetaldehyde increased from 0.188 to 0.836mg and from 0.183 to 0.823mg per 100ml of juice respectively. These low concentrations and narrow range seem to preclude these components as useful indicators of maturity. The rapid increase in Brix-acid and total sugar-acid ratio during the season provides a more sensitive indication of maturity in both cultivars.
