Effects of lycopene extract incorporation strategies on the quality attributes and protein digestibility of beef meatballs.

This study examined the effects of lycopene incorporation strategies, direct addition (LM), dissolution in lard (LOM) and homogenization after dissolution (LOHM) on beef meatballs qualities. The LOHM treatment significantly improved oxidative stability (reduced TBARS and carbonyl values) but compromised protein network formation, increasing viscous modulus (G″) and deteriorating texture. In contrast, LOM enhanced elastic network structure (higher storage modulus G') and textural properties. During digestion, LOHM exhibited a "digestive dichotomy": it promoted initial gastric proteolysis, increasing peptide diversity and low-molecular- weight peptides, yet induced protein aggregation that resisted intestinal hydrolysis, limiting free amino acids release. These results demonstrate that the finely dispersed, lycopene-stabilized emulsion created by LOHM facilitates early pepsin-mediated cleavage but also promotes aggregation/reorganization that hinders later intestinal enzyme access, representing a stage-dependent digestibility trade-off. This work provides novel insights for designing precision-functionality meat products with tailored digestive behaviors.