Influence of Huangjiu on flavor development in braised pork: A Flavoromics approach

Huangjiu, one of the three oldest fermented beverages in the world, plays a significant role in shaping the flavor profile of braised pork. This study systematically investigated its impact by analyzing changes in key flavor precursors-including amino acids, nucleotides, and fatty acids-and by employing electronic nose (E-nose), electronic tongue (E-tongue), and GC-MS to monitor the overall flavor evolution during thermal processing. The results demonstrated that alanine made a substantial contribution to the overall taste of the braised pork. Furthermore, IMP exhibited a taste activity value (TAV) greater than 1, indicating its direct contribution to the umami taste of the dish. Principal component analysis (PCA) of the E-nose and E-tongue data revealed distinct overall aroma and taste profiles between the control group and the experimental group. Significant differences were observed in the responses of specific electronic nose sensors (W2W, W2S, W1W, W1C, W5S) and taste sensors (bitterness, umami, saltiness). By integrating odor activity value (OAV) analysis with variable importance in projection (VIP) scores, ten volatile compounds were identified as key differential markers distinguishing the two groups. These included (E,E)-2,4-nonadienal, ethanol, nonanal, octanal, heptanal, 1-octen-3-ol, citronellal, hexanal, (E)-2-octenal, and phenylethyl alcohol. Therefore, the deodorizing and aroma-enhancing effect of Huangjiu is manifested in two ways: it prevents the excessive oxidation of lipids that leads to off-odors (such as 1-octen-3-ol and octanal), and it either dissolves and volatilizes off-odor components or directly contributes aromatic compounds with floral and fruity notes-such as phenylethyl alcohol and citronellal-to enrich the overall aroma profile of the braised pork. Further correlation analysis elucidated the underlying relationships. The influence of Huangjiu on the flavor of braised pork was strongly associated with changes in the levels of amino acids and fatty acids, particularly unsaturated fatty acids (UFAs). Specifically, the content of off-odor compounds showed a significant negative correlation with UFA content, whereas the levels of desirable flavor compounds were significantly positively correlated with the content of amino acids such as histidine and glycine.