The contribution of bitter blockers and sensory interactions to flavour perception

Introduction: There is a continued need for the application of flavour modifiers to improve the sensory profile of products within the functional food market. Additionally, psychophysical studies have tended to confine their scope to stimuli that elicit single sensations, and ingredients that are not always of most interest to the food industry. While basic taste-eliciting compounds and odourants have been used in functional food optimisation, modification can also include the addition of bitter-blocking ingredients. This study examines the impact that these modifiers have both alone and in conjunction with each other on the flavour of (+)-catechin containing model functional beverages.

Methods: The intensities of sweetness, bitterness, astringency and aroma were rated for (+)-catechin (CAT) aqueous solutions alone and containing a sweetener [sucrose or rebaudioside A (REB)], an odourant (vanilla or black tea), a bitter blocker [ß-cyclodextrin (CD) or homoeriodictyol sodium salt], and all combinations of each. Results: The use of sweeteners, both alone and in conjunction with bitter blockers, decreased the bitterness of CAT, while odourants had no effect. CD + REB significantly decreased the astringency of CAT. Astringency and bitterness of CAT was not altered by the addition of bitter blockers alone or in combination with odourants. Bitter blockers did not affect intensities of sweetness and aroma.

Conclusions: The use of sweeteners in combination with bitter blockers can lower the bitterness of (+)-catechin. The addition of bitter blockers may be used without a detrimental effect on the flavour profile of model beverages. Implications: Decreasing the bitterness of plant-derived, health-promoting compounds may be achieved through the application of certain sweet eliciting and bitter-blocking compounds, which in turn, may lead to increasing the acceptability of some functional foods for bitter sensitive consumer populations.