Dose-dependent effects of rosmarinic acid on formation of oxidatively stressed myofibrillar protein emulsion gel at different NaCl concentrations.

The effects of rosmarinic acid (RA) (12, 60 and 300μM/g protein) on the textural properties and stability of oxidized myofibrillar protein (MP) emulsion gels were investigated. A low dose (12µM/g) of RA significantly prevented the loss of thiol and ε-NH2 groups and the unfolding of the oxidized MP. However, a high dose of RA (300µM/g) covalently and non-covalently interacted with the MPs, which induced a significant loss of thiol and ε-NH2 groups and aggregation of the MPs, causing decreased solubility, resulting in a poor three-dimensional emulsion gel network, and hence, higher cooking loss and lower gel strength. Moreover, the emulsifying properties of the MP emulsion gel were jeopardized by 300µM/g RA. A high concentration of NaCl (0.6M) enhanced the interaction between RA and MPs, increasing deterioration of the internal structure and leading to extremely unstable emulsifying properties of the MP emulsion gel.