凍結前處理가 굴의 冷凍變性 防止에 미치는 效果 = The Effect of Pretreatment to Prevent Freezing Denaturation of Oysters

국문 초록 (Abstract)

凍굴의 凍結變性을 抑制하여 解凍時流出되는 drip量을 減少시키기 위하여 굴을 凍結前에 16種類의 添加物 溶液에 10分間 浸漬處理하여 凍結貯藏한 후 解凍하였을 때의 free drip量, expressible drip量, drip中의 全窒素量, DNA量, VBN量, 그리고 解凍後의 遊離水量 및 加熱 튀김減量 等을 定量하였다.
1) 試料의 個體에 따른 drip流出量은 個體가 작은 것이 큰 것보다 많았으며 處理液의 濃度가 높을수록 drip量이 적었다. 그리고 混合處理區가 單獨處理區 보다 drip流出量이 적었다.
2) drip中의 全窒素量은 大體로 drip流出量에 比例하였으며 混合處理液의 效果가 컸었다.
3) pH는 鹽處理區가 약간 低下하였고 燐酸鹽處理區는 7.0이상이었다.
4) 處理液의 濃度別 및 種類別에 따른 DNA의 變化는 drip流出量과 비슷한 경향을 나타내었다.
5) VBN은 食鹽處理區에서는 增加하였고 燐酸鹽處理區에서는 多少 減少하였으며 drip 流出量과는 반드시 比例하는 것은 아니었다.
6) Sucrose와 燐酸鹽處理區가 遊離水 流出抑制效果가 多少있었다.
7) 加熱튀김減量은 食鹽을 除外한 全處理區 모두 處理液의 濃度가 높을수록 적었다.

다국어 초록 (Multilingual Abstract)

It is well known that the frozen foodstuffs exude much drip on thawing. This undesirable drip loss is considered to be a measure of quality estimation and of the several factors affecting the drip loss, maintaining freshness of materials may be more important than any others.
In the present paper, therefore, the amount of drip and its quality changes were tested in order to find out effect of pretreatment as means of maintaining freshness with several salt solutions on the denaturation of frozen oysters.
After shelling, oysters divided into two groups as small and large were washed with fresh water and treated with solutions of sodium chloride, sucrose, poly-mixer(pyro-＋tri-;1:1), mixed phosphates(ortho-＋meta-＋para-; 1:1:1) and these mixture, and then refrigerated at -30℃ by semi-air blast freezer.
The total nitrgen, DNA, VBN, released water content and weight loss by cooking as well as the amount of free and expressible drips were also determined during 90 days storae at -25℃.
As results of this experiments, the small oysters exude more drip than the large ones. The amount of total drip decreased as the concentration of solutions increased and it is similar to the total nitrogen and DNA in the drip. The amount of VBN increased in the sodium chloride treatment contrary to decrease in the case of phosphate. On the other hand, the pH of drip dropped slightly in treatment with sodium chloride and rose in case of phosphate. The water holding capacity of oysters was counterproportional to the drip loss and the effect of solutions used in treatment.
The weight loss by cooking decreased in the all treatments except only one as the concentration of the solutions increased but sodium chloride exhibited adverse effect. It could be concluded from this study that pretreatments with solutions of some salts or sucrose would effective in maintaining the quality of frozen oysters.