Proceedings of the 16th Weurman Flavour Research Symposium E. Guichard & J.L. Le Quéré (Eds): Proc. 16th Weurman Flavour Research Symposium, 2021. DOI: 10.5281/zenodo.5946880 Generation of bitter blocker Maillard-dietary phenolic compound reaction products ADELINE BONNEAU, Edisson Tello and Devin G. Peterson Flavor Research and Education Center (FREC), Ohio State University (OSU), Columbus, Ohio, USA Abstract Bitterness is a well-known aversive taste that can negatively impact consumer’s acceptance. The aim of this study was to investigate the generation of bitter blocker compounds derived from the bitter dietary phenolic compound epigallocatechin gallate (EGCg) through the Maillard reaction. Reaction models were investigated using different reaction variables (temperature, time, moisture, nature of sugars and amino acids, and reactants molar ratio) to obtain different phenolic-Maillard reaction products. Isotope labelling experiments using carbon labelled sugars were performed to identify the reaction products and compare the different reaction models. The main resulting reaction products were further isolated and purified for sensory analysis and accurate identification purposes to discover bitter blockers. A total of fourteen isolated reaction products were identified by accurate mass spectrometry analysis (HRMS) and nuclear magnetic resonance (NMR). Those reaction products were evaluated by sensory analysis through 2-AFC test comparisons and bitterness intensity ratings to determine their bitterness modulation properties. Two reaction products were found to significantly decrease the bitterness perception of caffeine bitter samples. The optimised Maillard reaction conditions to produce those bitter blockers were further described to provide new knowledge and insight regarding the generation of bitter blocker compounds during food processing. Keywords: Bitterness, Bitterness Modulation, Maillard Reaction, Reaction Products, Bitter Blocker Compounds. Introduction Despite health recommendations, many healthy and natural food products (vegetables, whole cereals, vegetable proteins, etc.), as well as functional foods (enriched in vitamins, phytonutrients, fish oils, etc.), are often poorly consumed due to their bitter attributes [1, 2]. The reduction of bitterness by the addition of salts, sweeteners, strong flavours, or a debittering process remains challenging for the food industry because these methods affect the food quality and remove health-promoting bitter compounds [2, 3]. Thus, the advancement of food technology aimed to mask bitterness perception is needed. This work focused on a food-based strategy by using dietary phenolic compounds and Maillard reaction models to generate reaction products able to modulate the bitterness perception and act as bitter blockers. Bitter compounds and bitter blocker compounds have been reported in the literature to possess similar chemical structures that are competitive towards the different bitter receptors hTAS2Rs [4]. Thus, a strategy to generate bitter blocker compounds would be designed by the derivatisation of original bitter compounds into bitter blocker structures. In that way, the dietary phenolic compound epigallocatechin gallate (EGCg) was chosen as a potential bitter blocker compound precursor due to its low bitterness threshold in sensory analysis [5] and its activity toward the human bitter receptors hTAS2Rs [6, 7]. The Maillard reaction, which is accelerated during thermal food processing and has been previously reported to generate phenolic-reaction products [8], was chosen to derivatise the phenolic EGCg into potential bitter blocker products. Maillard reaction models were investigated using different reaction variables (temperature, time, moisture, nature of sugars and amino acids, and reactants molar ratio) with the phenolic EGCg. The main resulting EGCg-Maillard reaction products highlighted by isotope labelling experiments were further evaluated through sensory ana