茶葉半成品凍藏與解凍再行布球揉捻技術之研究
Other Title
Studies on Frozen Storage of Panned Tea Leaves and Ball-rolling Process after Defrosting in Pouchung Tea Manufacture
Journal
農特產品加工研討會專刊
Part Of
農業試驗所特刊第56號
Pages
149-161
ISBN
957-00-6655-5
Date Issued
1995-12
Date
1995-12
Author(s)
邱瑞騰
Ruey-Turing Chiou
Abstract
利用低溫貯存包種茶半成品，於布球揉捻勞力充裕時，再加以解凍加工，能有效解決布球揉捻勞力嚴重缺乏的問題。預計能於貯存5 日內解凍加工時則溫度設定於0℃以下均可，如貯存時間超過10日以上時採用-15℃～-20℃的溫度較為適宜。
低溫貯存包種茶半成品的水含量不能太高，否則對成茶的色澤不利，對解凍的作業也較費時，因此以經過初乾者為佳。半成品低溫貯存時先秤量適當之布揉葉量可加速葉溫之冷卻，而且能更有效保持包種茶的品質，對解凍作業亦較有效率。另外視貯存時間之長短，選擇不同盛裝之容器，可兼顧迅速冷卻葉溫的效果與保持爾後布球揉捻時之適揉性。解凍的方法以在室溫下並用風扇輔助的效果最好，而且解凍的時間不需要太久，對製茶的流程不會有影響。如半成品的水含量較高時，宜以80℃熱風解凍，兼具將茶葉再乾至適合布球揉捻含水量的效果。
利用色差計測定水色之變化，結果顯現亮度差異不太，綠色值在高水含量時隨貯存日數增加而減少，而黃色值增加。以80℃熱風解凍時黃色值明顯增加，可能和熱風有催化兒茶素的氧化有關。由茶黃質含量的分析結果顯示茶黃質含量和茶湯水色的變化無關。
Using low temperature to store the half dry condition Pouchung Tea, whenever the time being plenty of labor then remove the storaged Pouchung tea to re-treat rolling process; According to the results of the experiment for three years, we can make sure this method can solve the serisis problem whenever shortage of rolling labor. If we estimate to have plenty of labor within five days then we could set the temperature for storage under 0℃, or the storage time might over 10 days then the better way suggested is to store the half dry Pouchung Tea under -15℃~-20℃.
The water content for the storage of Pouchung Tea with half dry condition, couldn¡¦t be to high. It could effect the color of the appearance of made tea and extend the time for refrost of the tea, so the suggested water content of the half dry tea should have primary drying. If we preweight the tea before put into the refrigerator, then can make sure to cooling the tea leaves temperature more fast, not only could keep the quality of tea, but also more efficiency for the defrosting process. According to the period of the storage time, we could select different storage container, to assure the effect of fast cooling process and keep the tea leaves in proper condition for rolling process afterward.
The method for the defrosting process is under the condition of room temperature with air supplying by electric fan that could get best effect, and the time won¡¦t be too long to effect the tea manufacture process. If the water content of the half dry tea is too high, then we could using 80℃ hot air to blow and let the water content of tea suitable for the rolling process.
Using chrometer to measure the difference of the color of tea extract, the L value won¡¦t be much difference, the a value increase as the storage time increase, also the b value increase. Using 80℃ hot air blowing method the b value increase apparantly, this could be the hot air catalyst the catechins to oxidation According. to the color analysis of theaflavins, the color of tea extract won¡¦t be effected by the content of theaflavins.
Event(s)
農特產品加工研討會
Proceeding of A Symposium on Processing of Agricultural Products
Subjects
包種茶
炒菁葉
布球揉捻
凍藏
pouchung tea
panned leaves
ball-rolling process
frozen storage
Publisher
農業試驗所
Type
conference paper
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