Rheological, physical and sensory characteristics of light ice cream as affected by selected fat replacers

In this study, some rheological, physical and sensory properties of light (5% fat) ice cream in comparison with the control sample (10% fat) were investigated as functions of fat replacer type [guar gum (GG), basil seed gum (BSG) and their mixture (MGB, 50:50)] and concentration (0.35, 0.45, 0.50 and 0.55%). All samples exhibited shear-thinning and thixotropic behaviors. The fat reduction resulted in higher melting rate and lower breakdown coefficient, but a contrary trend was observed by increasing fat replacer concentration. Generally, BSG and MGB represented a more shear-sensitive thixotropic nature and melting resistance than GG samples. Regarding the first dripping time, GG light ice creams started dripping first, followed by MGB, then BSG light samples at the same gum concentration. The existence of synergistic relationship for consistency coefficient and plastic viscosity of light mixes was explored by MGB. A synergistic effect was observed for all rheological properties of MGB control sample, with exception of pseudoplasticity. At lower gum concentrations, there were not any significant differences found between the creaminess of samples at the same concentrations, but at 0.55% gum, BSG sample showed the highest value for this property. BSG was found to decrease coarseness, coldness, and meltdown of light ice creams more effectively than GG. Principal components analysis (PCA) revealed that the sensory properties had an inter-dependent with each other. Moreover, PCA scores divided the samples into three groups: full fat ice creams, light samples with 0.35 and 0.45% BSG and MGB, and light ice creams with 0.5 and 0.55% BSG and MGB.