Lowry method was applied to measure the sol-ubility of αs-casein and β-lactoglobulin protein in solvent system consisting of sodium dodecyl-sulphate (SDS) and β-mercaptoethanol (ME). The approach was applied to αs-casein and β-lactoglobulin heated at temperature (145oc) at 95% relative humidity.
The solubility of αs-casein in water and the sol-vent mixture as a function of heating time in the RH 95% environment was high and increased with increasing heating time. In contrast β-lactoglobulin showed a zero solubility in water at all heating time and very low solubility in mixture of solvents. The differences between the two proteins are apparent even after short (20minutes) heating time. The color results of both proteins indicated that the darkening increased with increasing heating time. Heated αs-casein had a wide molecular weight distribution range.
This was evident from both SDS-PAGE and the GPC/Malls –RI systems.