Multispectral, omics, and structural analysis of crispy pork ribs: Effects of combined pretreatment with different proteases on multidimensional quality characteristics

This study combined multispectral analysis, microstructural characterization, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and untargeted metabolomics to investigate the effects of pretreatment with different protease combinations on the quality characteristics and compositions of crispy pork ribs and elucidate the corresponding mechanisms. The results indicate that crispy pork ribs pretreated with various enzyme combinations exhibited higher pH and moisture content, lower frying loss, and texture characteristic values. Endogenous fluorescence spectroscopy, ultraviolet–visible absorption spectroscopy, and secondary structural analysis of myofibrillar proteins (MPs) demonstrated that protease pretreatment promoted protein degradation and induced structural unfolding. SDS-PAGE results further confirm that protease pretreatment accelerated protein degradation, which led to considerably reduced and optical density values in high- and low-molecular-weight bands, respectively. Untargeted metabolomics findings show that pretreatment with different enzymes promoted a significant increase in the relative content of substance components that contributed positively to the taste of crispy pork ribs (such as 16-hydroxy hexadecanoic acid, nicotinic acid, glutaric acid, etc.). Comprehensive evaluation demonstrated that pretreatment with compound enzyme formulation (papain + bromelain + collagenase) yielded the most substantial improvement in the quality characteristics of crispy pork ribs. • Effects of enzyme combination pretreatment on crispy pork ribs quality were assessed. • Pretreatment with three enzyme combinations promoted protein degradation in pork ribs. • Pretreatment with enzyme combinations increased characteristic taste compounds in pork ribs. • The papain–bromelain–collagenase pretreatment resulted in the best improved quality of crispy pork ribs.