脫水冷凍蔬菜之試驗（一）脫水冷凍法對冷凍甘藍品質之影響

Primarily Report on the Dehydrofreezing of Vegetables (I) Effect of Dehydrofreezing Method on the Quality of Frozen Cabbage

為了供應臺灣夏季蔬菜，泠凍蔬菜是解決不足供應之一補救途徑，但因許多葉菜類所含水分特高，應用一般冷凍加工法難獲優良之品質，因此本研究選用脫水冷凍加工法將甘藍為試驗材料經過殺菁、脫水及冷凍加工探討其可行性，供發展夏季用泠凍葉菜類之參考。應用1.2%食鹽水來殺菁甘藍所得之製品色澤較一般熱水為佳，並用熱風脫去甘藍所含之水分約40%，使以後之復水率較佳。脫水冷凍之甘藍可被官能評審者所接受，評審員發現脫水冷凍甘藍經三個月泠凍貯藏後之品質如香氣及風味均較一般冷凍製品者為佳。為了減少脫水泠凍蔬菜在加工過程中生菌數之增加，可於脫水之末了應用蒸汽噴一下即可。本研究並提供一甘藍脫水冷凍之流程圖。

In order to supply more vegetables for summer time in Taiwan, frozen vegetables would meet this requirement. However, some leaf-vegetables always contain too much water, and they could not be frozen well by the conventional freezing methods though they are favored by our Chinese people. Thus, a dehydrofreezing technique was introduced for this purpose. Cabbage was chosen as the test sample and a series of blanching, dehydration and freezing operations was carried out in this experiment. The cabbage that was blanched in 1.2% sodium chloride solution (98°±2℃) had a better color intensive than that by the conventional hot water blanching. The sample in which the moisture was removed about 40% prior to freezing showed a better edible quality and a better water recovery ratio than sample of more water removal. The dehydrofrozen cabbage was acceptable through the sensory evaluation. Panelists found that dehydrofrozen cabbage after stored for three months showed a better quality in flavor and taste than that undehydrofrozen sample. Using hot steam as an elute to the end stage of dehydration will eliminate the microorganism contamination as indicated by this experiment. A scheme for dehydrofreezing of cabbage has also been proposed.