Comprehensive investigation of coffee acidity on eight different brewing methods through chemical analyses, sensory evaluation and statistical elaboration

Abstract

Even if the acids composition and their role in coffee still need to be clarified, acidity is one of the main sought-after features in coffee and it is becoming one of the main quality markers. Hence, the aim of this paper was to evaluate the main parameters influencing coffee acidity with a focus on carboxylic acids. To the best of our knowledge, this is the first study regarding filter coffee prepared from specialty and mainstream coffee, differently roasted and through eight diverse extraction methods. Coffee cup chemical composition in terms of organic and chlorogenic acids, caffein and physicochemical parameters were correlated with perceived sourness and mouthfeel to better understand the influence of extracted compounds on the final beverage acidity. Statistical tools revealed that a major impact of chlorogenic acids emerged in pH and titratable acidity, while the sensorial sourness appeared more correlated with organic acids concentration. Thus, these findings suggests that organic acids could be potential predictors of beverage perceived acidity.