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 <i>Jiangxiangxing</i> 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.