以除濕乾燥法製造柿餅之研究

Study of Persimmon Dehydration Using Dehumidification Method

史宏財(Horng-Tsair Shih) ； 許明仁(Ming-Jen Sheu)

《桃園區農業改良場研究報告》 20期 (1995/03) Pp. 23-35

https://doi.org/10.29567/ZHWHGX.199503.0003

摘要

本研究為解決以自然日曬法製造柿餅過程中常因陰雨天候造成大量腐敗，期以人工除濕乾燥製造出優良品質之柿餅。本試驗將總量935公斤之柿青，分四批先後逐日置於控制溫濕度之乾燥室內（28.0－30.5˚C、RH 48.3－69.8%），經5次間歇循環操作（每個循環為除濕18小時，停機6小時）製成柿餅；結果顯示其較自然日曬法約快兩天，並發現除濕乾燥室之除濕機除濕能力不足時，會導致乾燥室之濕度上升，在柿青進行乾燥之第三或第四天，即柿子果實開始成熟軟化時，發生腐爛現象。以除濕乾燥法製造之柿餅，其色澤與日曬乾燥法所製者相同，呈均一誘人之金黃色。果糖及葡萄糖為柿餅中主要之糖類，在乾燥過程中因水蒸發而濃度增加，而以自然日曬法者較高。柿餅之硬度在除濕乾燥後四天達到最高之530克；自然日曬法製得之柿餅，則在乾燥後約七天才達到相同之硬度。柿餅乾燥過程中水分活性持續下降，但仍未達常溫下可以保存之程度。

關鍵字

柿餅 ； 除濕乾燥 ； 品質分析

並列摘要

Dehydration of persimmons (Diospyros kaki L.) using dehumidification method at the range from 30°C to 35°C and 50 to 65% relative humidity environment resulted in the highest yield and the best quality of dehydrated persimmons, as compared to the products made from conventional sun drying method.Dehumidification of persimmons at above conditions for 18 hours and then turn off the dehumidifier for six hours was the best operation condition for persimmon moisture balance and case hardening prevention. The dehumidification process took five days to remove about 61.3% moisture of the persimmon. It is two days shorter as compared to sun drying method. Texture of the persimmon decreased to the lowest strength within two days due to fruit softening, and then gradually increased due to water removal and skin formation of dehumidified persimmon. The dehumidified persimmon showed golden color appearance as that by sun drying. Glucose and fructose were the main sugars of persimmon, both of those sugars increased during the drying process. Sun drying persimmon showed a higher amounts of glucose and fructose than the dehumidified persimmon.

並列關鍵字

Dehydrated persimmon ； Dehumidification ； Quality evaluation