浸漬條件對桑椹再製酒色澤安定性之影響

Abstract

色澤是評估桑椹再製酒(Mulberry liqueur)最重要的品質項目之一。本實驗之目的在探討浸漬萃取條件對於桑椹再製酒色澤呈現的影響。不同糖類和添加量的桑椹再製酒中，以添加12.5%葡萄糖的桑椹再製酒具有最高的可滴定酸、縮合單寧與總花青素萃出量，且在浸漬萃取14週後保有最低的色度比(Tint value)，呈現最佳的紅色色澤。隨著糖添加量的增加，桑椹成分在再製酒中的溶出明顯受到抑制而降低。以澄清桑椹汁添加40%酒精度基酒之試驗結果顯示，隨著貯藏時間增長，再製酒的色度比增加，酒中之縮合單寧與總花青素含量則同時下降，肉眼觀察有輕微沉澱現象發生，這些沉澱物可能是縮合單寧與花青素聚合導致溶解度下降所致。以不同酒精含量之基酒製造桑椹再製酒之試驗中，以60%酒精含量的桑椹再製酒溶出之可滴定酸、總酚、縮合單寧與總花青素萃取量最多，且浸漬萃取至第14週時之酒液色度比亦為所有樣品中最低，紅色色澤的呈現最佳。在桑椹再製酒製造時添加不同的共色素(copigment)，以添加500mg/L catechin的酒液在浸漬萃取第14週時的總花青素含量最高且色度比最低，顯示添加500mg/L catechin可提高桑椹再製酒的色澤安定性。

Color is one of the most important quality factors for mulberry liqueur. The objective of this study is to investigate the additions of sugar, quantity of sugar, alcohol concentration of base liquor, and copigment on the color stability of mulberry liqueur during maceration. The results show that mulberry liqueurs with 12.5% glucose addition elute the highest titratable acidity, condensed tannins and total anthocyanins contents among samples. In addition, tint value of 12.5% glucose added mulberry liqueur sample is the lowest among the samples after maceration for 14 weeks, which displayed the best red color appearance. Increase quantity of sugar added to mulberry liqueur significantly inhibits solute elution during maceration. Addition of clarified mulberry juice directly to 40% alcohol liquor, the condensed tannins and total anthocyanins contents decreased as tint value increased. Precipitation observed in this sample is probably due to the polymerization of tannin and anthocyanin which resulted in solubility reduction. Mulberry liqueurs made from 60% alcohol maceration resulted in the highest titratable acidity, total phenols, condensed tannins and total anthocyanins contents extraction, as compared to mulberry macerated with other lower alcohol content base liquor. At the end of 14 weeks maceration, the mulberry liqueurs made from 60% alcohol had the lowest tint value, which also displayed the best red color among the treatments. Addition of 500mg/L catechin as copigment into the mulberry liqueur maceration resulted in the highest total anthocyanins extraction and the liqueur also presents the lowest tint value as compared to the addition of other copigments, which suggests that addition of 500mg/L catechin may increase the color stability of mulberry liqueur.