添加發芽蕎麥對生啤酒品質與抗氧化特性的影響

Effects of Germinated Buckwheat Adjunct on the Quality and Antioxidative Activities of Draft Beer

蔡旻諺(Min-Yen Tsai)

指導教授 ： 游若篍

國立臺灣大學/生物資源暨農學院/食品科技研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.10918

摘要

蕎麥 (Fagopyrum esculentum Moench; Buckwheat) 含有豐富且完整的營養成分，其酚類化合物顯著高於其他穀類。蕎麥為芸香苷 (rutin) 主要攝取來源，芸香苷為類黃酮類的一種，具有良好之抗氧化能力。啤酒也含有抗氧化物質，適度飲酒可以增加血漿中的抗氧化物質、高密度脂蛋白的含量和減少實驗動物低密度脂蛋白的氧化傷害，同時也可以降低酒氧化反應，減少風味物質改變，防止啤酒老化。因此本實驗目的是探討發芽蕎麥應用在啤酒釀造之可行性，以期增加生啤酒 (draft beer) 之抗氧化能力。
實驗第一部分以芸香苷為指標，探討最適浸泡時間、發芽溫度和發芽天數，實驗結果顯示浸泡時間為8小時，發芽溫度為25℃，發芽時間7天可以得到393.06 ± 20.36 mg/100 g芸香苷，高於未發芽蕎麥的15.67 ± 1.38 mg/100 g，且總酚含量、類黃酮含量、DPPH清除自由基能力和亞鐵離子螯合能力均優於未發芽蕎麥和大麥麥芽。第二部分為評估添加30%最適發芽條件之蕎麥於大麥麥芽中，對啤酒製造過程之發酵特性和抗氧化能力之影響。實驗結果顯示，蕎麥生啤酒的pH值略低於大麥生啤酒和市售生啤酒，可滴定酸度略高於大麥組和市售組，酵母菌菌數略低於大麥組，但高於市售組，其他發酵特性三組間並無顯著差異。蕎麥組芸香苷含量約為34.28 ± 0.61 μg/mL，大麥組和市售組並不含芸香苷，且蕎麥組之總酚含量、類黃酮含量和DPPH清除自由基能力均優於大麥組和市售組，亞鐵離子螯合能力則是無顯著差異。將蕎麥組調整糖酸比後進行消費者喜好性品評，不論是顏色、香氣、口感和整體接受度，三組間均無顯著差異，顯示蕎麥生啤酒有潛力開發為高抗氧化能力之生啤酒。

關鍵字

蕎麥 ； 芸香苷生啤酒 ； 抗氧化能力

並列摘要

The endogenous antioxidants in beer contribute to the control of oxidative reactions, improve flavor stability of beer and protect against beer aging. Moreover, beer drinking has been reported to increase plasma antioxidant and anticoagulant activities and affect plasma lipid levels in humans. Buckwheat (Fagopyrum esculentum Moench) is a good source of polyphenols and flavonoids, particularly rutin. In this study, we determined the antioxidative activity of buckwheat, an adjunct for buckwheat draft beer.
Results showed that the optimum malting conditions to enrich rutin in hulled buckwheat are steeping 8 hrs and after a 7-day germination at 25℃. Germinated buckwheat’s total phenolic contents, total flavonoid content, DPPH-radical scavenging activity and metal chelating activity were significantly higher (p＜0.05) than ungermnatied buckwheat and malt. In addition, yeast counts of buckwheat draft beer were significantly lower than barley draft beer (p＜0.05). The pH value of buckwheat draft beer was significantly lower than the others (p＜0.05). The acidity of buckwheat draft beer was significantly higher than the others (p＜0.05). However, there was no significant difference (p＞0.05) among °Brix, specific gravity, total sugars, and reducing sugars. Among three draft beer, buckwheat draft beer showed the highest total phenolic content, total flavonoid content and DPPH-radical scavenging activity. Ferrous ion chelating activity did not show significant difference between buckwheat draft beer and barley draft beer (p＞0.05). In addition, there was no different among three draft beer on sensory evaluation value (p＞0.05). In conclusion, buckwheat draft beer may provide a novel alternative of functional draft beer to the consumers.

並列關鍵字

buckwheat ； rutin ； draft beer ； antioxidative activity

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