Student Research Projects

Quantitative Determination of Catechin and Epicatechin in Chocolate and Correlation with Bitter Taste

Student Tatyana Zvonareva, '16
Faculty Mentor(s)
Department Chemistry
Course Chemistry 480: Instrumental Methods of Analysis

Abstract

Catechin and epicatechin are polyphenols produced by plants as secondary metabolites. Specifically, these polyphenols are present in cacao beans and have been shown to contribute to the human sensory bitter taste due to interactions with the TAS2R receptor family. The main objective of this study was to extract and quantify these compounds in samples of the commercially available chocolate, as well as, to correlate the presence of these compounds with bitter taste. It is anticipated that the polyphenol content, as represented by catechin and epicatechin, in dark chocolate will be greater than in milk chocolate. Both dark and milk chocolate varieties of two brands of chocolate (LindtTM and GhiradelliTM) were obtained from the local market. Catechin and epicatechin were extracted using liquid-liquid extraction technique to isolate the polyphenols from the food sample. Derivization of these compounds was further applied in order improve volatility and generate derivatives applicable for GC analysis. Gas Chromatography-Mass Spectrometry (GC-MS) analysis was applied in order to identify and quantify the polyphenols. The analytes were identified based on the retentive index data and compared against mass spectrometry data available from the NIST library.