溫度與“平核無”柿果酒精脫澀及軟化之關係

Abstract

本試驗以本省生產之’平核無’柿果為材料，進行酒精脫澀之試驗。酒精用量每公斤柿果至少4ml，效果較佳。在30℃下，酒精處理時間達16小時即足以誘發柿果脫澀。果實以酒精脫澀之速度隨溫度增加而加速，在25℃下需4日；在30℃下需3日；而在35及40℃下則只需2日即可完成脫澀。脫澀時之軟化現象，隨脫澀溫度增加而減緩；另外，在脫澀前以48.5℃熱風處理柿果3小時，亦有減緩脫澀後的軟化現象。 The disappearance of astringency was studied in ‘Hiratanenashi’ persimmon (Diospyros kaki Thunb.) fruits which had been treated with ethanol. For adequate astringency removal and fruit quality the optimum ethanol concentration was 4 ml ethanol per kg fresh fruit at 30℃. Astringency disappearance only when fruit had been in ethanol vapor for at least 16h. The decrease in astringency was effected by temperature. The rate of decrease was high with higher temperatures. The times required to reach completely deastringency were 4, 3, 2 and 2 days at 25°，30°，35° and 40℃, respectively. A gradual decrease in flesh firmness during deastringency, and there were significant differences in the rate among the various holding temperature ranging from 25° to 40℃. The rate of decrease in firmness was loww with higher temperatures. In addition, the decrease of firmness was inhibited by the fruits treated with high temperature force air (48.5℃) for 3h before ethanol deastringent treatment.