Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/29244
標題: 柿果二氧化碳脫澀之生理變化和微細構造
Studies on Physiological and Ultrastructural Changes of Persimmon (Diospyros kaki L.) Fruit with Carbon Dioxide De- astringency
作者: 傅琦媺
Chi-Mei, Fu
關鍵字: persimmon fruit
柿果
deastringent
soluble tannin
tannin cell
脫澀
可溶性單寧
單寧細胞
出版社: 園藝學系
摘要: 柿果脫澀的方法很多,其中以二氧化碳處理最為快速、有效,且可減少水 傷之生成,本試驗即採用此法做為試驗之用。柿果在30℃高溫下以二氧化 碳處理約二十四小時後即可完全脫澀。經二氧化碳脫澀處理之後,柿果所 含糖度降低,主要可能來自於可溶性單寧的干擾,因其對糖度計亦有折射 的作用;經脫澀處理後的柿果,可溶性單寧轉變為不溶性,減少糖度計之 折射作用,故使糖度降低。在研究柿果脫澀時,發現脫澀前後果肉所含之 離心水有明顯下降的趨勢:經脫澀處理十六小時後,離心水含量自66.18% 降至 26.93%;此外,乾燥亦可促成柿果的脫澀,因而推測水分變化是促 成柿果脫澀之因子。以高濃度(100%)二氧化碳處理柿果時,細胞間pH值 下降,氫離子進入胞內,改變細胞膜內外之離子濃度,於是膜內的正電荷 (如鉀離子)輸出細胞外,以平衡電荷。此時,因胞外離子濃度增加,促 使果肉滲透壓增加,伴隨著低氧下水解酵素活性的增加,使細胞壁之大分 子水解,促使細胞內的水分子外移,造成細胞的脫水。由試驗結果顯示, 這些變化皆發生在柿果脫澀完成(二十四小時)之前,因而推測細胞的脫 水,使可溶性單寧聚合成為不溶解性,才是造成柿果脫澀的因子。由解剖 顯微鏡及電子顯微鏡之觀察,發現柿果中之單寧細胞在脫澀前後,其形態 上有極大之差異。柿果未經脫澀處理前,所含之可溶性單寧量極高,經電 子顯微鏡的觀察發現:未脫澀柿果之單寧,因其為水溶性,在前製備過程 中易被洗去,或者經單寧細胞壁上的孔隙流出,凝結在細胞壁上。經二氧 化碳處理完成脫澀之柿果,所含之可溶性單寧聚集形成大分子,成為不溶 解性,存在於特化的單寧細胞中,故在切口表面不復見黑色單寧散佈的情 況;經電子顯微鏡觀察,發現單寧細胞壁較為平滑,表面無或極少孔隙存 在,亦無流出物凝結其上。
There are many methods to make persimmon fruit deastringent. The fast and effeciency method is carbon dioxide treatments. More than over, it could decrease the physiological disordor- partial softening, and this method was used in this persidure. Persimmon fruit can fully lost astringency under 30℃ with carbon dioxide treatment after 24 hours. The total soluble solid in persimmon fruit decreased during deastringency with carbon dioxide. The main effect is reducing soluble tannin content, since soluble tannin reflect with reflectometer. The soluble tannin of persimmon fruit polymerized to unsoluble form after deastringency treatment caused total soluble solid declined. In this studies of persimmon deastringency, centrifugal water is obviosly declined after deastringency. Centrifugation water declined from 66.18% to 26.93% after 16 hours treated with carbon dioxide. And drying can make the persimmon fruit deastringent Since these reasons, the data suggest that water''s transference is involved in deastringence. The intercellular pH value in persimmon fruit declined when treated with 100% carbon dioxide. Hydrogen ions in free space was extended into cell and changed the ions concentration between inner and outer space. Then positive ions like as potassium ions of internal space outpoured into intercellular space to balance charge. When ions concentration of intercellular space increased, making the osmotic pressure increased, in coupling with under low oxygen hydroxidase activity increased to make big molecular hydrolysis. Then water leak out of cell result of dehydration of cells. According to the results of this experiment we suggested that dehydration can make soluble tannin polymerize to unsoluble form resulting of deastringency of persimmon fruit. There were some difference in ultrastructure between astringent and deastringent fruit during carbon dioxide treatment. In deastringent fruit, protrusions are pore were found in tannin cell surface.
URI: http://hdl.handle.net/11455/29244
Appears in Collections:園藝學系

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