The Effect of Adding Different Varieties of Osmanthus on the Antioxidant Activity and Flavor of Barley Beer

Osmanthus fragrans has a pleasant aroma, and different varieties have different aromas and colors. This study systematically assessed how the inclusion of various Osmanthus fragrans cultivars influences critical beer attributes, including physicochemical parameters, sensory characteristics, antioxidant capacity, and volatile flavor profiles. The findings demonstrated that osmanthus addition markedly decreased beer turbidity ( p < 0.05) and enhanced the TPC by as much as 30%. The content of monophenols in beer also increased significantly, especially catechins and gallic acid, which increased by an average of 25 and seven times ( p < 0.05), respectively. Vanillic acid was established as a key determinant of the DSA in osmanthus beer through correlation and cluster analysis ( r = 0.9, p < 0.01). GC–MS analysis identified 50 volatile compounds, with increase in dihydro-β-ionone and irisine content in the osmanthus beer, and sensory evaluation confirmed that the mix and aurantiacus varieties achieved the highest overall acceptability, demonstrating the effectiveness of osmanthus in enhancing the beer's overall flavor and functional properties.