Controlled formation of emulsion gels stabilized by salted myofibrillar protein under malondialdehyde (MDA)-induced oxidative stress.
This study presented the cold-set gelation of emulsions stabilized by salted myofibrillar protein (MP) under oxidative stress originated from malondialdehyde (MDA). Gel properties were compared over a range of MDA/NaCl concentrations including gel viscoelastic properties, strength, water-holding capacity (WHC), amount of protein entrapped, and microstructure. The oxidative stability of emulsion gels as indicated by lipid hydroperoxide was further determined and compared. Results indicated that emulsion stabilized by MP at swollen state under certain ionic strengths (0.2-0.6 M) was the premise of gel formation under MDA. In the presence of intermediate MDA concentrations (2.5-10 mM), the emulsion gels showed an improved elasticity, strength, WHC, and oxidative stability. This improvement should be mainly attributed to the enhanced protein-protein cross-linkings via MDA, which were homogeneously formed among absorbed and/or unabsorbed proteins, entrapping a greater amount and fractions of protein within network. Therefore, the oil droplets were better adherent to the gel matrix. Nevertheless, addition of high MDA concentrations (25-50 mM) led to the formation of excessive covalent bonds, which might break protein-protein bonds and trigger the desorption of protein from the interface. This ultimately caused "oil leak" phenomena as well as the collapse of gel structure and, thus, overall decreased gel properties and oxidative stability.
College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, China.
Feibai
F
Zhou
College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, China.
Weizheng
W
Sun
College of Light Industry and Food Science, South China University of Technology, Guangzhou 510640, China.
Mouming
M
Zhao
D000818:Animals; D004548:Elasticity; D004655:Emulsions / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D008315:Malondialdehyde / Q000737:chemistry*; D008460:Meat / Q000032:analysis; D009124:Muscle Proteins / Q000737:chemistry*; D009210:Myofibrils / Q000737:chemistry*; D009994:Osmolar Concentration; D018384:Oxidative Stress; D012965:Sodium Chloride / Q000737:chemistry; D013552:Swine
D004655:Emulsions; D005782:Gels; D009124:Muscle Proteins; D012965:Sodium Chloride; D008315:Malondialdehyde
cold-set; emulsion gel; malondialdehyde; myofibrillar protein; protein oxidation