Underlying formation mechanisms of ultrasound-assisted brined porcine meat: The role of physicochemical modification, myofiber fragmentation and histological organization

Ultrasound treatment has been a good hurdle technique for meat curing processing, where both physical and chemical consequences can be involved towards final quality of obtained products. However, the specific correlation between ultrasound parameters and muscle fiber fragmentation and myofibrillar microstructural changes during curing deserve further evaluation. In present study, we comparatively studied the effect of ultrasound-assisted brining (UAB) and static brining (SB) on the muscle proteolysis events and microstructural/morphological variation of porcine meat as well as the physicochemical indices and histological characteristics. The results showed that UAB (20 kHz, 315 W for 1 h) could markedly enhance the muscle proteolysis with higher free-/peptide-bound alpha-amino-nitrogen (α-NH2-N) content (P < 0.05) than SB treatment and greatly improved the fragmentation of muscle fiber tissues of cured meat. Meanwhile, UAB processing favored more opening structures of myofibrillar proteins with more hydrophobic groups being exposed. The quantitative histological analysis revealed that, compared with SB treatment, UAB could significantly increase the gap between muscle fibers and the swelling of the perimysium (P < 0.01), proving an efficient curing process with better textural and water holding properties.