Rheological and structural properties of β-lactoglobulin and basil seed gum mixture: Effect of heating rate

The effects of heating rate and addition of basil seed gum (BSG) as a novel hydrocolloid on the rheology and microstructure of beta-lactoglobulin (BLG) gel were studied using low amplitude dynamic oscillatory shear (SAOS) and confocal laser scanning microscopy (CLSM) measurements. BLG solution and BLG-BSG mixtures at different ratios (20:1, 10:1, 5:1 and 2:1) were heated from 20 to 90 degrees C at four heating rates (0.5, 1.5 and 10 degrees C/min). Gelation temperature of beta-lactoglobulin was reduced by decreasing of heating rate and increasing BSG ratio. The maximum G' at the end of heating period was reduced greatly by decreasing the BLG-BSG ratio. BLG-BSG mixed systems developed a relatively weak gel, which it enhanced when the ratio was changed from 20:1 to 2:1. Addition of BSG to 10% BLG solution makes a separated phase network in which increasing BSG content induced very fine stranded structure of protein. Therefore, it is possible to achieve distinct structures by mixing different ratios of hydrocolloids at various heating rates. (C) 2012 Elsevier Ltd. All rights reserved.