title: Role of disulphide linkages between protein-coated lipid droplets and the protein matrix in the rheological properties of porcine myofibrillar protein-peanut oil emulsion composite gels.
abstract: The objective of the study was to establish disulphide interaction between protein-coated oil droplets and the surrounding protein matrix in myofibrillar protein (MP)-emulsion composite gels. An MP-stabilized peanut oil emulsion was treated with 0, 1, 3, 5 and 10 mM N-ethylmaleimide (NEM, a sulphydryl-blocking agent) and subsequently incorporated into a bulk MP sol to produce 5%-lipid, 2%-protein composites at pH 6.2. About 69% of sulphydryls in the emulsion (1% protein) were blocked by 1 mM NEM, and almost all were bound at ≥3 mM NEM. The loss of free sulphydryls resulted in a significant drop in the storage modulus (G') and rupture force of the composite gels. Microstructural examination revealed pores and oil leakage from emulsion droplets by NEM treatments, corresponding to declining rheological properties of the MP-emulsion composites. The results supported the hypothesis that disulphide cross-linking between MP-coated oil droplets and protein matrix contributed to the stabilization and reinforcement of protein-emulsion composite gels formed in comminuted muscle foods.
authors.affiliation: State Key Laboratory of Food Science and Technology, and School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Mangang
authors.initials: M
authors.lastname: Wu
authors.forename: Youling L
authors.initials: YL
authors.lastname: Xiong
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004041:Dietary Fats; D004044:Dietary Proteins; D004548:Elasticity; D004655:Emulsions; D005033:Ethylmaleimide / Q000737:chemistry; D005526:Food, Formulated / Q000032:analysis; D005782:Gels; D008055:Lipids / Q000737:chemistry*; D008461:Meat Products / Q000032:analysis*; D009124:Muscle Proteins / Q000737:chemistry*; D009994:Osmolar Concentration; D000074241:Peanut Oil; D010938:Plant Oils / Q000737:chemistry; D012212:Rheology; D013439:Sulfhydryl Reagents / Q000737:chemistry*; D013499:Surface Properties; D034421:Sus scrofa; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D004041:Dietary Fats; D004044:Dietary Proteins; D004655:Emulsions; D005782:Gels; D008055:Lipids; D009124:Muscle Proteins; D000074241:Peanut Oil; D010938:Plant Oils; D013439:Sulfhydryl Reagents; D005033:Ethylmaleimide