The roles of sucrose on the retronasal thresholds of tea catechins and polyphenols in water‐based system

Abstract

AbstractThe objective of this study was to determine the role of sucrose in the retronasal detection thresholds of caffeine, theobromine, and tea catechins, including epicatechin gallate (ECG), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallic acid (GA), and gallocatechin gallate (GCG), in a water‐based system. The detection threshold tests were conducted using standard practice for determination of taste thresholds by a forced choice ascending concentration series method of limits in ASTM E679‐05 on different water‐based matrices with varying degrees of sucrose levels. The Best Estimate Thresholds (BET) of caffeine, theobromine, ECG, EGC, EGCG, and GCG in water were 73.88, 70.83, 47.58, 40.03, 61.91, and 29.06 mg/kg, respectively. An increase in BETs was observed with an increased level of sucrose in the water‐based model for caffeine, and each of the catechins except theobromine and gallic acid. This result suggests a possible gallic acid‐sucrose interaction. This study reported the increase of detection threshold of bitter and astringency‐causing compounds with addition of sucrose in water‐base model system. This can provide another perspective of using sucrose to mask bitterness and astringency in coffee and tea products.Practical applicationsConsumption of coffee and tea has been increasing worldwide. Catechins and caffeine are the chemical compounds that give bitterness and astringency in green tea and coffee products, making consumers avoid these products. Reduction of bitterness and astringency in coffee and green tea products is crucial to expand the market. The outcome of this study indicated an increase in BETs with an increased level of sucrose in the water‐based model for caffeine, and each of the catechins except theobromine and gallic acid. This means that addition of sugar can help reducing bitterness and astringency perception by increasing individual threshold of such compound. Findings from this study can contribute beverage industry to reformulating their beverage products more appealing to their target consumers.