Mechanism Behind the Inhibition of Sweetness Intensity of Aspartame by Guar Gum and Locust Bean Gum

Current research on the effects of macromolecular hydrocolloids on sweetness is mainly focused on the properties of hydrocolloids and their texture-taste interactions. In this paper, the influence of two kinds of nonionic food hydrocolloids, Guar gum (GG) and Locust bean gum ( LBG) on the taste of aspartame (APM) was studied. Sensory evaluation revealed high concentrations of GG and LBG significantly inhibited the sweetness intensity of APM, especially when their concentrations were higher than C* (coil overlap concentration). The mechanism of this phenomenon was investigated using an artificial taste receptor model and isothermal titration calorimetry. The association constant for APM, determined by the artificial taste receptor model, decreased in the presence of GG and LBG. More bound water was found in GG and LBG with an increase in the hydrocolloid concentration, especially at higher than C*. Additionally, water diffusion was hampered and this contributed to the lower sweetness intensity. We thus determined the influence of the hydrocolloid on the binding of sweeteners with the receptor, its water mobility as well as its diffusion behavior in the hydrocolloidal texture. The information obtained enables an understanding of the mechanism behind the effects of macromolecular hydrocolloids on taste.