Evaluation of the Bitter-Masking Potential of Food Proteins for EGCG by a Cell-Based Human Bitter Taste Receptor Assay and Binding Studies

Abstract

Epigallocatechin gallate (EGCG) has been ascribed to several health benefits, but its bitter taste influences the liking of products with high concentrations of this compound. β-Casein, in particular, and several gelatins are known as strong binders of EGCG, contrary to β-lactoglobulin. The current study aimed at relating the EGCG-binding characteristics of those proteins and their food-grade equivalents to their effects on reducing bitter receptor activation by EGCG in vitro and their bitter-masking potential in vivo. Also in the bitter receptor assay, β-casein showed the strongest effect, with a maximum reduction of hTAS2R39 activation of about 93%. A similar potency was observed for Na-caseinate. β-Lactoglobulin had little effect on bitter receptor activation, as expected based on its low binding affinity for EGCG. The bitter-masking potential of Na-caseinate was confirmed in vivo using a trained sensory panel. β-Lactoglobulin also slightly reduced EGCG bitter perception, which could not be directly related to its binding capacity. The bitter receptor assay appeared to be a valid tool to evaluate in vitro the efficacy of food proteins as complexing agents for masking bitterness.

Binding of Caffeine and Quinine by Whey Protein and the Effect on Bitterness

“…Similar discrepancies have been noted elsewhere. For example, Bohin and others (, ) evaluated the masking of bitterness of EGCG by different proteins. EGCG is typically considered to be a ligand for the bitter receptor hTAS2R39.…”

“…One strategy to reduce bitterness is the prevention of interactions between bitterants and taste receptors via physical means, such as encapsulation or molecular binding (Coupland and Hayes ). Proteins can be useful in bitterness‐masking in foods because they have the ability to bind small molecules and have demonstrated capacity to alter taste and aroma perception (Bohin and others ).…”

Taste-Masking Effect of Chlorogenic Acid (CGA) on Bitter Drugs Evaluated by Taste Sensor and Surface Plasmon Resonance on the Basis of CGA–Drug Interactions

“…A second approach to reducing bitterness is to prevent bitterness perception peripherally, using techniques such as encapsulation, molecular inclusion of cyclodextrins 4,5) or complexation with ion exchange resin, 6) tannate, 7,8) fatty acids 9) or food proteins. 10) A third strategy is the application of bitter taste receptor blockers. 11,12) For example, it has been found that 6-methoxyflavanones can decrease the response of the bitter receptor hTAS2R39 toward diverse bitter compounds.…”

Preparation and Evaluation of Poly-γ-glutamic Acid Hydrogel Mixtures with Amlodipine Besylate: Effect on Ease of Swallowing and Taste Masking

“…2,3) At the cognitive level, the perceived inhibition of bitterness occurs in the central nervous system in the brain via taste-taste interactions. An alternative approach is to prevent bitterness perception peripherally, using techniques such as encapsulation, molecular inclusion of cyclodextrins, 4,5) complexation with ion-exchange resins, 6) tannate, 7,8) fatty acids 9) or food proteins 10) or the addition of bitterness-masking substances such as chlorogenic acid. Electrostatic interactions between basic bitter active ingredients and chlorogenic acid attenuate the binding of the bitter active ingredients to bitterness receptors.…”