Proteomic, Fatty Acid and Mineral Profiles of PDO Arouquesa and Commercial Crossbred Beefs: A Tool for Certification

Protected Designation of Origin (PDO) beef products are recognized for their higher quality, although the native breeds used often show lower productivity compared to commercial crosses. This study aimed to compare the proteome profiles of Arouquesa and crossbred beef using 2D-DIGE, and evaluating crude protein, energy, and fatty acid composition. Arouquesa beef had higher energy values (p < 0.05), whereas crossbred samples showed greater protein content (p < 0.05). Moreover, Arouquesa beef had higher proportions of microminerals, namely zinc, iron, and manganese (p < 0.05). The Arouquesa breed also presented higher proportions of most fatty acids, including saturated, monounsaturated, and polyunsaturated. Proteomic analysis identified 34 differentially abundant proteoforms from 23 proteins. In Arouquesa, proteins associated with muscle contraction (MYLPF, TNNT1), glycolysis/gluconeogenesis (TPI1, GPD1), oxygen transport (HBB, HBA), and heat shock response (CRYAB, HSPB1) were more abundant or had altered spot patterns, suggesting their roles in meat tenderness, color, and fat-related characteristics. Conversely, crossbred beef showed elevated levels of glycolytic enzymes (PGM1, ENO3, and some proteoforms of TPI1 and GPI) and structural proteins (MYL1), related with higher muscle growth and different fiber composition. The identified proteins provide possible molecular markers that distinguish Arouquesa from commercial breeds. These validated proteins in the future can support breed characterization and verification of PDO certification specifications.