The effect of aged pork fat on the quality and volatile compounds of Chi-aroma Baijiu

Abstract This study aimed to explore the effect of aged pork fat on the quality and volatile compounds of Chi-aroma Baijiu during the ageing stage. Result showed that glycerol and total ester contents of CBN, CB1, CB3 and CB5 were significantly higher than that in BL (P < 0.05), but total acid contents did not change significantly (P > 0.05). Moreover, there was a difference in volatile compounds concentration and OAVs among the Chi-aroma Baijiu samples. With the year of aged pork fat increased, concentrations of esters and aldehydes were increased and then decreased, which reached highest in CB1. CB1 had highest OAVs of medium and long-chain ethyl esters and four aldehydes ((E)-2-nonenal, octanal, (E)-2-decanal, (E)-2-octenal) were the characteristic volatile compounds of Chi-aroma Baijiu during ageing process owing to their OAV > 10. Therefore, CB1 had the highest sensory score, with intense Chi-aroma and pleasant aftertaste. OPLS-DA further effectively distinguish different Chi-aroma Baijiu soaking with different years of aged pork fat, and confirmed 31volatile compounds (especial ethyl esters) were the key volatile compounds responsible for significant differences in Chi-aroma Baijiu. Combined with the results of sensory evaluation, GC-MS and OAVs, one-year aged pork fat was the best to product Chi-aroma Baijiu.