Review in Metabolic Modulation of Higher Alcohols in Top-Fermenting Yeast

Abstract

Higher alcohols, produced by top-fermenting yeast during wheat beer brewing, are the major abundant flavor compounds, and have great impact on wheat beer smell and taste. Adequate quantity of higher alcohols could give wheat beer with full and enjoyable taste and improve the harmony of aroma profile. However, superfluous higher alcohols would bring off-flavor to the beer and are harmful to human health. There are few published articles about wheat beer, however, many investigations into barley beer are applicable to wheat beer production, as the yeast used in wheat beer fermentation and barley beer belongs to Saccharomyces cerevisiae. In this review, we focus on characteristic of higher alcohols, and various studies that are applicable to barley and wheat beer. Particularly, information about fermentation conditions affecting the production of higher alcohols and the expression of related genes, and directional modification of higher alcohols metabolic pathway in top-fermenting yeast are discussed in this review, which concentrates on studies published in the last 5–6 years.