Comparative Characterization of Pork Jowl and Three Commercial Cuts from DLY Pigs: Instrumental Quality, Nutritional Composition, Water Distribution, and Volatile Profiles

This preliminary within-animal study focuses on the comprehensive characterization of pork jowl (PJ) by comparing it with pork belly (PB), Boston butt (BB), and spare ribs (SR) collected from the same ten castrated Duroc × Landrace × Yorkshire (DLY) pigs; headspace volatile analysis used a matched subset of six pigs. Instrumental quality, proximate composition, amino-acid and fatty-acid profiles, low-field nuclear magnetic resonance (LF-NMR) water distribution and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) volatile profiles were evaluated. PB exhibited the lowest shear force, hardness, and chewiness. Across the four pork cuts, crude protein content ranged from 16.87% to 18.10%, whereas crude fat content ranged from 13.03% to 22.20%. BB had the lowest crude fat content (13.03%) and relatively high protein (18.10%) and amino-acid contents. PJ showed highest content of monounsaturated fatty acids (MUFAs) and the lowest numerical atherogenic (AI) and thrombogenic indices (TI), but also the highest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio. LF-NMR showed that PJ had the highest T23 and P23 values, consistent with its higher cooking and centrifugal losses. Sixty-five headspace volatile compounds were tentatively identified under the standardized 80 °C HS-SPME conditions. OPLS-DA differentiated the four cuts, and ten compounds meeting the combined criteria of VIP > 1, q < 0.05, and OAV > 1 were retained as candidate discriminant aroma-relevant compounds. Overall, the four cuts exhibited distinct quality profiles: PJ combined a MUFA-rich lipid fraction with greater free-water mobility and water loss, PB showed the greatest instrumental tenderness, BB had the lowest crude fat content and relatively high protein and amino-acid contents, and SR exhibited the greatest headspace volatile abundance. The data provide a reference for cut-specific utilization of pork raw materials.