茶叶添加方式对酿造啤酒理化特性及感官品质的影响

在啤酒酿造工艺的煮沸和主发酵阶段分别添加乌龙茶,探讨茶叶不同添加方式对啤酒理化特性、抗氧化能力、啤酒贮存稳定性以及感官特性的影响。结果显示,与未添加茶叶的啤酒产品(对照组CG)相比,在煮沸阶段(煮沸添加组BG)和主发酵阶段(主发酵添加组MG)分别添加0.3g/L的茶叶均提高了酵母发酵速率;添加茶叶的两个茶啤酒产品(煮沸添加组和主发酵添加组)的DPPH自由基清除能力分别提升至82.74%和89.21%、ABTS+自由基清除能力分别提升至41.53%和51.49%、铁离子还原能力分别提升至36.49和43.83 mg/L,且成品茶啤酒贮藏期间的抗老化能力提高;茶啤酒中总酚以及儿茶素(EGC、C、EGCG、EC、GCG、ECG)和咖啡碱(CAF)含量升高,其中,主发酵添加组茶啤酒样品总酚和EGCG含量显著高于对照组和煮沸添加组啤酒(P0.05),分别达到734.40和8.43 mg/L。进一步的感官品评结果显示添加茶叶提高了啤酒产品的茶香气和茶滋味,其中主发酵添加组啤酒的茶香气、茶滋味及酒体协调性最好。由此可知,在啤酒酿造工艺中添加茶叶提高了酵母发酵速率,增强了啤酒中酚类物质含量及其抗氧化和抗老化性能,同时也为啤酒增添了新的茶风味产品。

Effects of tea addition method on physicochemical characteristics and sensory quality of beer products

Beer is rich in a variety of nutrients and functional components, including carbohydrates, amino acids, vitamins, and phenolic compounds. It is the third beverage product in terms of consumption and sales after water and tea. Beer output in industry scale reached 50.61 million tons in China in 2013, but 34.11 million tons in 2020, indicating a gradual decline from 2014 to 2020. Crafted beers gradually begin emerging from abroad, with the increase of consumption level, particularly rich in the mouth feel and flavor. Alternatively, tea is rich in nutrients and substances (tea polyphenols, tea polysaccharides, and theanine) with diverse biological properties, including high antioxidant activity, anti-aging, and lipid-lowering effects. There are many tea resources in China, where the output ranks first all over the world. Therefore, the combination of tea and beer can be expected to enhance the tea flavor of beer for better health function. In this study, oolong tea was added in the boiling stage and the main fermentation stage of the beer brewing process, thereby investigating the effects of different addition on physicochemical properties, antioxidant capacity, storage stability, and sensory properties of beer products. The main results were as follows: The fermentation rate of beer increased significantly when adding 0.3% (m/v) oolong tea at the boiling stage (boiling addition group) and the main fermentation stage (main fermentation addition group), compared with the controlled group. The DPPH radical scavenging ability, ABTS+ radical scavenging ability, and iron ion reducing ability of two products in the tea beer (boiling addition group and main fermentation addition group) increased to 82.74% and 89.21%, 41.93% and 51.49%, and 36.49 mg·L-1 FeSO4 and 43.83 mg·L-1 FeSO4, respectively. The anti-aging ability of finished tea beer was improved during storage. The contents of caffeine (CAF) and catechins increased significantly in the tea beer, including epigallocatechin (EGC), catechin (C), epicatechin gallate (EGCG), epigallocatechin gallate (EC), epigallocatechin gallate (GCG), epigallocatechin gallate (ECG). The contents of total phenol and EGCG in tea beer samples from the main fermentation supplemental group were significantly higher than those of the controlled group and boiling supplemental group (P < 0.05), where were 734.4 mg GAE/L and 8.43 mg/L, respectively. The sensory evaluation showed that the addition of tea improved the tea aroma and tea taste of products, where the coordination of tea aroma, tea taste and wine body of beer in the main fermentation addition group presented the best among the three beer products. The scale-up beer production also confirmed the feasibility of tea beer brewing. This finding can provide a promising reference to develop tea beer products.