Nyhan Laura, Sahin Aylin W, Arendt Elke K
School of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
APC Microbiome Ireland, University College Cork, Cork, Ireland.
Eur Food Res Technol. 2023;249(1):167-181. doi: 10.1007/s00217-022-04142-4. Epub 2022 Nov 27.
The non-alcoholic beer (NAB) sector has experienced steady growth in recent years, with breweries continuously seeking new ways to fulfil consumer demands. NAB can be produced by limited fermentation of non- yeasts; however, beer produced in this manner is often critiqued for its sweet taste and wort-like off-flavours due to high levels of residual sugars and lack of flavour metabolites. The use of in limited co-fermentation with non- yeasts is a novel approach to produce NABs with varying flavour and aroma characteristics. In this study, lab-scale fermentations of KBI 12.1 and C6.1 with FST 1.7 were performed and compared to a brewer's yeast, WLP001. Fermentations were monitored for pH, TTA, extract reduction, alcohol production, and microbial cell count. The final beers were analysed for sugar and organic acid concentration, free amino nitrogen content (FAN), glycerol, and levels of volatile metabolites. The inability of the non- yeasts to utilise maltotriose as an energy source resulted in extended fermentation times compared to WLP001. Co-fermentation of yeasts with lactic acid bacteria (LAB) resulted in a decreased pH, higher TTA and increased levels of lactic acid in the final beers. The overall acceptability of the NABs produced by co-fermentation was higher than or similar to that of the beers fermented with the yeasts alone, indicating that LAB fermentation did not negatively impact the sensory attributes of the beer. C6.1 and FST 1.7 NAB was characterised as fruity tasting with the significantly higher ester concentrations masking the wort-like flavours resulting from limited fermentation. NAB produced with KBI12.1 and FST1.7 had decreased levels of the undesirable volatile compound diacetyl and was described as 'fruity' and 'acidic', with the increased sourness masking the sweet, wort-like characteristics of the NAB. Moreover, this NAB was ranked as the most highly acceptable in the sensory evaluation. In conclusion, the limited co-fermentation of non- yeasts with LAB is a promising strategy for the production of NAB.
近年来，无酒精啤酒（NAB）行业经历了稳步增长，啤酒厂不断寻求新方法来满足消费者需求。无酒精啤酒可以通过非酵母的有限发酵来生产；然而，以这种方式生产的啤酒由于残留糖分含量高且缺乏风味代谢物，其甜味和类似麦芽汁的异味常常受到批评。将[具体微生物名称]与非酵母进行有限的共发酵是一种生产具有不同风味和香气特征的无酒精啤酒的新方法。在本研究中，进行了[具体微生物名称]KBI 12.1和C6.1与[具体微生物名称]FST 1.7的实验室规模发酵，并与酿酒酵母WLP001进行比较。监测发酵过程中的pH值、总酸度（TTA）、浸出物减少量、酒精产量和微生物细胞计数。对最终啤酒的糖分和有机酸浓度、游离氨基氮含量（FAN）、甘油以及挥发性代谢物水平进行分析。与WLP001相比，非酵母无法利用麦芽三糖作为能源导致发酵时间延长。酵母与乳酸菌（LAB）的共发酵导致最终啤酒的pH值降低、总酸度升高以及乳酸水平增加。共发酵生产的无酒精啤酒的总体可接受性高于或类似于仅用酵母发酵的啤酒，这表明乳酸菌发酵不会对啤酒的感官特性产生负面影响。C6.1和FST 1.7的无酒精啤酒具有水果味，较高的酯浓度显著掩盖了有限发酵产生的类似麦芽汁的风味。用KBI12.1和FST1.7生产的无酒精啤酒中不良挥发性化合物双乙酰的含量降低，被描述为“水果味”和“酸性”，增加的酸度掩盖了无酒精啤酒甜的、类似麦芽汁的特征。此外，这种无酒精啤酒在感官评价中被评为最可接受的。总之，非酵母与乳酸菌的有限共发酵是生产无酒精啤酒的一种有前景的策略。
