Effect of basil seed gum (BSG) on textural, rheological and microstructural properties of model processed cheese

Abstract

This study focuses on the textural, rheological and microstructural properties of a model processed cheese (44–48% wt/wt dry matter and 30% fat content) developed with different concentrations of rennet casein (6–10% wt/wt) and basil seed gum (BSG) (0–1% wt/wt). The frequency sweep test showed the η*, G′ and G″ values increased with increasing BSG concentration in all formulations with the same protein/solid content. Increasing levels of BSG also led to more elastic behaviour in the structure of processed cheeses. Regardless of the protein content, the “sol–gel transition” temperature of the model processed cheeses increased significantly (p < 0.05) when the concentration of the added BSG was increased. The concentration of added BSG had much more effect on meltability of the processed cheese than the protein content. However, flowability of the samples was dependent mainly on the protein content. The particle size data and confocal laser scanning microscopy (CLSM) images showed that BSG contributed to the emulsification of the oil and both the oil droplets and BSG chains were dispersed in a continuous protein phase. Similar to the BSG/milk proteins aqueous systems, the BSG chains possibly created a web network throughout the protein matrix of the processed cheese and strengthened the network formed by casein strands. By adding BSG, it was possible to make processed cheeses with higher firmness but slightly lower meltability, and at lower cost owing to the lower protein and higher moisture contents.