Citation: Santos, M.J.; Correia, E.; Vilela, A. Exploring the Impact of α-Amylase Enzyme Activity and pH on Flavor Perception of Alcoholic Drinks. Foods 2023, 12, 1018. https://doi.org/10.3390/ foods12051018 Academic Editors: María José Jara-Palacios and Dolores Hernanz Received: 31 January 2023 Revised: 17 February 2023 Accepted: 25 February 2023 Published: 27 February 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). foods Article Exploring the Impact of α-Amylase Enzyme Activity and pH on Flavor Perception of Alcoholic Drinks Maria João Santos 1 , Elisete Correia 2 and Alice Vilela 3, * 1 Department of Agronomy, University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal 2 Center for Computational and Stochastic Mathematics (CEMAT), Department of Mathematics, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal 3 Chemistry Research Centre (CQ-VR), Department of Agronomy (DAgro), School of Agrarian and Veterinary Sciences (ECAV),University of Trás-os-Montes e Alto Douro, 5001-801 Vila Real, Portugal * Correspondence: avimoura@utad.pt Abstract: The introduction of a drink in the mouth and the action of saliva and enzymes cause the perception of basic tastes and some aromas perceived in a retro-nasal way. Thus, this study aimed to evaluate the influence of the type of alcoholic beverage (beer, wine, and brandy) on lingual lipase and α-amylase activity and in-mouth pH. It was possible to see that the pH values (drink and saliva) differed significantly from the pH values of the initial drinks. Moreover, the α-amylase activity was significantly higher when the panel members tasted a colorless brandy, namely Grappa. Red wine and wood-aged brandy also induced greater α-amylase activity than white wine and blonde beer. Additionally, tawny port wine induced greater α-amylase activity than red wine. The flavor characteristics of red wines due to skin maceration and the contact of the brandy with the wood can cause a synergistic effect between beverages considered “tastier” and the activity of human α-amylase. We can conclude that saliva-beverage chemical interactions may depend on the saliva composition but also on the chemical composition of the beverage, namely its constitution in acids, alcohol concentration, and tannin content. This work is an important contribution to the e-flavor project, the development of a sensor system capable of mimicking the human perception of flavor. Furthermore, a better understanding of saliva–drink interactions allow us to comprehend which and how salivary parameters can contribute to taste and flavor perception. Keywords: panel of tasters; pH; α-amylase; lipase; salivary parameters 1. Introduction From an early age, taste and aroma have been known for walking together in a single direction [1]. It is the combination of that leads to the recognition of the most varied sensory experiences to which the human being’s palate is constantly subjected. Trigeminal sensations—or “mouthfeel”—are defined as “a group of sensations that is characterized by the tactile response in the mouth” [2] and described as “tactile prop- erties (sensation) perceived from the moment that food or drink—solid, semi-solid or liquid—is placed in the mouth until swallowed” [3]. These sensations, together with the taste and olfactory sensations (ortho- and retronasal perception), contribute to the flavor of the food/drinks that are essential in the acceptance of these products by consumers [4]. Understanding the factors affecting flavor perception may provide clues to drive food consumption toward keeping a proper nutritional status [5]. Apart from food characteristics, flavor perception is strongly influenced by oral phys- iology, namely saliva [5]. Saliva’s constitution is approximately 99% water, and the rest is inorganic and organic compounds [6,7]. The pH of saliva is between 6.2 and 7.4 [8]. Being slightly acidic or basic, saliva is a highly viscoelastic fluid and has unique properties that facilitate chewing, digestion, homeostasis, and flavor perception, among many other things [9,10]. Moreover, in addition to dilution, the buffering capacity of saliva has also Foods 2023, 12, 1018. https://doi.org/10.3390/foods12051018 https://www.mdpi.com/journal/foods