Chlorogenic acid-mediated gel formation of oxidatively stressed myofibrillar protein

The effect of chlorogenic acid (CA) at different concentration levels (0, 6, 30, and 150 mu mol/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 alpha-helix conformation as well as tertiary structure of MP. CA at 150 mu mol/g produced the greatest increase in MP surface hydrophobicity and insolubility. The physicochemical changes with 6 and 30 mu mol/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 mu mol/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. (C) 2015 Elsevier Ltd. All rights reserved.