Modulation of freeze-thaw stability of emulsified sausage gels by Abelmoschus manihot (L.) medicus flower: Multi-scale structural and metabolomic evidence.

Repeated freeze-thaw cycles can impair the structural and physicochemical stability of myofibrillar protein-based emulsified gel systems. This study evaluated the cryoprotective effects of Abelmoschus manihot (L.) Medicus flower (AMF; 0%, 1%, 2%, and 4%, w/w) in emulsified sausage gels subjected to six freeze-thaw cycles. Compared with the control, AMF-treated samples showed lower thawing and cooking losses and improved emulsion stability. After six freeze-thaw cycles, cooking loss was reduced by 8.55%, 6.47%, and 0.93% in the AMF-1%, AMF-2%, and AMF-4% groups, respectively, compared with AMF-0%. Microstructural observations indicated that AMF addition contributed to a denser gel network and fewer freeze-induced voids. AMF also alleviated oxidative deterioration, as shown by lower Thiobarbituric acid reactive substances (TBARS) values and surface hydrophobicity, as well as better retention of free sulfhydryl groups and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity. Metabolomic analysis identified 485, 585, and 607 differential metabolites in the AMF-1%, AMF-2%, and AMF-4% groups compared with the control, with changes mainly associated with lipid metabolism, amino acid metabolism, central carbon metabolism, and flavonoid-related pathways. Overall, 2% AMF showed a relatively favorable balance between gel stabilization and oxidative protection. These findings suggest that AMF may be a potential natural ingredient for improving the freeze-thaw stability of emulsified meat products.