Microstructural and dynamic oscillatory aspects of yogurt as influenced by hydrolysed guar gum

Abstract

SummaryThe objective of the current study was to explore the influence of crude, purified and hydrolysed guar gum at low and high concentrations on gel structure stability of yogurts at 4 °C throughout 21 days of storage. The rheology and microstructure of yogurts had been perceived by Bohlin rheometer (Malvern Instrument, UK) and cryo‐scanning electron microscopy (Cryo‐SEM), respectively. The viscoelastic behaviour of yogurts characterised at 25 °C exhibited weak gel structural properties (Gʺ > Gʹ). Cryo‐SEM had been used for microstructural image processing. The acidic and enzyme hydrolysed guar gum at low (0.3%) and high (1%) concentrations led to yogurt gels with fine‐stranded microstructure, while gelation with crude, purified and basic hydrolysed guar gum demonstrated diverse behaviour of depletion flocculation, visually observed even at low concentrations of crude guar gum (0.1%) as a thin layer of phase‐separated material. Conclusively, guar gum in its hydrolytic form enhances better structural and rheological properties.