Polyacrylamide gel electrophoresis

Gel electrophoresis

Protein aggregation

Enzyme

Chemistry

Antioxidant

Water holding capacity

Lipid oxidation

Food science

Chromatography

Biochemistry

Myofibril

Food Chemistry

This work explored the effects of protein unfolding and cross-linking induced by lipid oxidation (linoleic acid, OLA) on the gel water-holding capacity (WHC) of beef myofibrillar proteins (MP). Medium concentration of OLA (≤6 mM) caused the increase of gel WHC from 55.2% to 65.1%, while relative high OLA concentration (>6 mM) decreased the gel WHC. When the OLA concentrations increased from 0 to 10 mM, the population of immobile water of gel decreased from 92.91% to 78.97%, whereas that of free water increased from 6.13% to 19.80%, suggesting that OLA treatment regardless concentration was harmful for gel WHC. However, medium OLA concentrations (≤6 mM) caused the shifting of α-helixes to β-sheets in MP gel, exerting positive effect on gel WHC. Protein unfolding and cross-linking jointly determined the increased gel WHC at moderate oxidative modification. Additionally, the protein aggregation at high OLA concentration resulted in decreased gel WHC.

Mechanisms of change in gel water-holding capacity of myofibrillar proteins affected by lipid oxidation: The role of protein unfolding and cross-linking