Effects of Addition of Different Amounts and Varieties of Grapes on Aroma, Physicochemical Indexes and Antioxidant Activity of Fruit Beer

In order to explore the application value of different grape varieties in fruit beer brewing and their effects on beer quality, we studied the effects of addition of different levels (30% and 40%, V/V) of Syrah or Merlot grape mashes on the aroma, physical and chemical indexes and antioxidant activity of fruit beer. Besides, grape beer with better quality was determined by sensory evaluation. The results showed that both grape varieties increased the concentration and antioxidant properties of phenols including 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity, ferric and cupric ion reducing power abilities, and significantly elevated the acidity and alcohol concentration of beer. The beer made with the addition of 30% Syrah or 40% (V/V) Merlot exhibited the highest content of aroma compounds, which increased by 190.55% and 152.65%, respectively, when compared with the control group. Sensory evaluation showed that the beer made with the addition of 30% Syrah tasted best. In general, the addition of different varieties of grape mashes had a positive effect on improving beer quality and aroma, which could become an important direction for the development of diversified beer products in the future.