Chlorogenic acid-mediated gel formation of oxidatively stressed myofibrillar protein

• Chlorogenic acid (CA) affects OH-induced protein structural changes.
• CA enhances myofibrillar protein (MP) unfolding induced by oxidation.
• Low and medium concentrations of CA promote MP gelation.
• High concentrations of CA suppress the gel-forming capacity of MP.

The effect of chlorogenic acid (CA) at different concentration levels (0, 6, 30, and 150 μmol/g protein) on porcine myofibrillar protein (MP) gelling potential in relation to chemical and structural changes was investigated. The results showed that CA generally inhibited protein carbonyl formation but did not prevent sulphydryl and amine losses caused by oxidation. The presence of CA intensified oxidation-initiated loss of α-helix conformation as well as tertiary structure of MP. CA at 150 μmol/g produced the greatest increase in MP surface hydrophobicity and insolubility. The physicochemical changes with 6 and 30 μmol/g CA led to a remarkably enhanced gelling capacity of MP and augmented the positive effect of oxidation in building an elastic gel network. However, CA at 150 μmol/g was detrimental to the MP gelation. The result can explain why processed meats with phenolic-rich spices and herbs often exhibit variable texture-forming properties.