玫瑰浸漬酒顏色品質之研究

Abstract

本論文針對玫瑰浸漬酒的製程，瞭解酒液成分與色澤之變化，並著重於顏色品質之提升。玫瑰浸漬酒於浸漬期間，影響色澤最重要的花青素，於浸漬第二日便已溶出大部分，之後隨著浸漬時間的延長，酒的顏色品質反而下降，尤以褐變的情形最為嚴重，故為增進玫瑰浸漬酒的顏色品質，浸漬的時間最長應不超過二日。玫瑰經50 ℃乾燥12小時後，可使含水量降至20 ％，花青素仍殘留90 ％，可降低浸漬過程中的酵素性褐變，有效維持玫瑰浸漬酒液的色澤，乾燥後之花瓣能萃出之花青素亦較鮮花來的多，乾燥可大幅減少原料的重量及體積，減少運輸及貯藏的成本，故建議乾燥為玫瑰浸漬酒之前處理。又從浸漬酸度、酒精度及時間探討其對顏色品質之影響，發現添加0.6 ％左右的檸檬酸可抑制浸漬期間的褐變；酒精度越低時間越長則酒液中花青素的含量越高，但褐變情形也越嚴重。故建議之浸漬條件為24小時，酸度為1.8∼2.0 ％，酒精度則為55∼60 ％。

This thesis was to investigate the method of processing and the changes of compounds and colors during soaking of rose liqueur. The improving of color quality was emphasized. During the soaking process, the amount of anthocyanins, the most important factor affecting the color of the liqueur, reached the maximum around the second day. Then, the quality of color declined with the increasing of soaking time especially browning. In order to improve the color quality of rose liqueur, the soaking time should not be longer than 2 days. After oven-drying for 12 hours, the moisture content of rose petals decreased 20 %, but 90% of anthocyanins were able to retain. Drying can slow down the browning during soaking, and keep color quality of rose liqueur more effectively. Moreover, it decreases weight and volume of raw materials resulting in the reduction of the cost during transportation and storage. As a result, drying of rose petals as a preliminary treatment before manufacturing of rose liqueur is suggested. From the study on the effects of pH, ethanol content and soaking time on color quality, it was found that browning during soaking can be slowed down by addition of 0.6 % citric acid. The concentration of anthocyanins increased with time and decrease with ethanol content; however, the degree of browning also increased with the increase in these factors. As a result, the optimal soaking conditions were as follows: soaking time of 24 hours; acidity at 1.8~2.0 %; and ethanol content of 55~60 %.