Advances in the study of bitter compounds in alcoholic beverages: A review and implications for the production of Chinese Huangjiu

Bitterness is a critical sensory attribute that influences the consumer acceptance and production quality of Huangjiu (Chinese rice wine). While moderate bitterness contributes to its complexity, excessive levels disrupt flavor harmony and hinder industrial mechanization. This review provides a comprehensive summary of the origin, identification, and control of bitter compounds in alcoholic beverages, with particular emphasis on Huangjiu. Drawing on recent advances in sensory-guided fractionation, mass spectrometry, and taste-directed isolation, this review outlines methodologies that have been successfully applied to wine, sake, and beer, and discuss their implications for Huangjiu. Available evidence suggests that bitter peptides may contribute more strongly than free amino acids to Huangjiu bitterness, although systematic reconstruction/omission tests remain scarce. Notably, hydrophobic peptides derived from rice and wheat proteins may be responsible for residual bitterness, based on analogy to rice-based fermentations and limited Huangjiu taste-guided identifications. A critical analysis of debittering strategies—including adsorption, masking, and enzymatic approaches—is also presented. Where applicable, engineering recommendations are presented as indicative pilot ranges rather than universally validated operating conditions. This review offers valuable insights and practical guidance for improving the sensory quality of Huangjiu and advancing its moderniza. • This review summarizes techniques for identifying bitter compounds in alcoholic beverages. • Key bitter compounds in wine, beer, sake, and Baijiu are compared. • Bitterness in Huangjiu is not mainly from amino acids, which are below taste thresholds. • Hydrophobic bitter peptides from rice and wheat may cause bitterness in Huangjiu. • Bitterness-reduction strategies: adsorption, masking, enzymatic, and combined methods.