Germination-induced cyanide accumulation during the grain hydration process of Jiangxiangxing Baijiu

Cyanide, a key precursor of ethyl carbamate, remains poorly characterized during the grain hydration stage of Baijiu production. This study for the first time demonstrated that grain hydration during Jiangxiangxing Baijiu significantly enhances dhurrin accumulation driven by sorghum germination. Within 48 h, dhurrin levels increased sharply (up to 15 mg/kg, representing a 15-fold rise) accompanied by a corresponding increase in free cyanide, reaching up to 3.3 mg/kg (an 8-fold increase). The high temperature and moisture conditions during hydration markedly promoted sorghum germination. Varieties with high germination capacity exhibited significantly higher cyanogenic potential, accumulating up to 1.7-fold more dhurrin than that of the less germinable varieties. Ultrasonic pre-treatment effectively inhibited germination and shortened the hydration duration, reducing dhurrin and free cyanide by 40.9 % and 28.5 %, respectively. These results provide theoretical and practical guidance for the upstream control of ethyl carbamate precursors and the optimization of Baijiu grain treatment.