Effect of temperature and sodium bicarbonate combined on aggregation, rheology and conformation of low-salt chicken myofibrillar protein.

To study the impact of temperature (4–50 °C) and sodium bicarbonate (0.4%) on the solubility, protein aggregation and conformation of low-salt (1 mmol/L sodium chloride) chicken myofibrillar protein, the changes in turbidity, particle size, protein secondary and tertiary structures were investigated. There was no significant difference in pH when it did not exceed 30 °C, then a significant increase (p < 0.05) when it was above 30 °C. The solubility, total and reactive sulfhydryl groups, and apparent viscosity increased first and then decreased (p < 0.05), and reached the maximum values at 30 °C; whereas the turbidity, particle size, α-helix, and random coil contents showed opposite trends. Additionally, the fluorescence peak experienced a noticeable redshift with rising temperatures; β-turn content significantly increased but β-sheet content decreased significantly. Finally, combining sodium bicarbonate with a temperature of around 30 °C could enhance chicken myofibrillar protein solubility and change the protein structure under a low-salt condition. [Display omitted] • Sodium bicarbonate decomposes resulting in increasing pH when it was above 30 °C. • Maximum solubility, sulfhydryl groups, and apparent viscosity located at 30 °C. • Fluorescence peak experienced a noticeable redshift with rising temperatures. • Sodium bicarbonate enhanced protein solubility, changed the structure at low-salt condition. [ABSTRACT FROM AUTHOR]