Insights into free fatty acid profiles and oxidation on the development of characteristic volatile compounds in dry-cured ham from Dahe black and hybrid pigs

The aims of this study were to investigate the roles of free fatty acid (FFA) profiles and oxidation in the formation of characteristic volatile compounds in ham produced from Dahe black (DW) and hybrid breed (Yorkshire x Landrace x DW, YLDW; and Duroc x Landrace x Yorkshire, DLY) pigs using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF-MS). Among the three types of hams studied, DW ham exhibited the highest total contents of FFAs (11,088.91 & mu;g/kg), volatile flavor compounds (3750.867 & mu;g/kg), aldehydes and alcohols. A total of 38 FFAs and 80 volatile compounds were identified in the three hams. According to odor activity values, 18 odorant-active compounds, including isovaleraldehyde, heptanal, 2-meth-ylbutyraldehyde, decanal, hexanal, n-octanal, nonanal, 1-octen-3-ol, methional and eucalyptol, which mainly comprised aldehydes and alcohols, were selected for the discriminatory analysis between hams produced from DW, YLDW and DLY pigs. Furthermore, correlation analysis demonstrated that the oxidative decomposition of polyunsaturated fatty acids (i.e., trans-9-octadecenoic, cis-9,12-linoleic, & gamma;-linolenic, & alpha;-linolenic, and arachidonic acid) is essential for the formation of volatile characteristics of ham. These results indicated that FFAs and volatile profiles of ham were breed dependent, and that the formation of volatile profiles in ham is closely related to lipid oxidation.