Determination of Theobromine in Cocoa Products Using Liquid Chromatography: A Review

This review aims to critically evaluate and compare published high-performance liquid chromatography (HPLC) methods for quantifying theobromine in cocoa-based products, with the aim of identifying a single analytical approach that is both practical for routine use in food manufacturing settings and readily transferable to quality control laboratories within cocoa production facilities. Theobromine is the principal alkaloid in cocoa beans and plays a critical role in the quality of cocoa-based products, influencing taste, aroma, texture, and health benefits. In addition to cocoa, theobromine is present in smaller amounts in green coffee beans, tea, and cola nuts, contributing to the characteristic bitter taste of chocolate and related products. HPLC is widely employed to determine organic compounds, including theobromine in cocoa products, due to its high resolution, reproducibility, and suitability for complex food matrices such as chocolate and cocoa powder. Compared to other techniques like capillary electrophoresis or gas chromatography, HPLC offers superior sensitivity for non-volatile and thermally labile compounds like theobromine, requires minimal derivatization, and accommodates aqueous mobile phases. Among the various detection methods coupled with HPLC, mass spectrometry is a highly feasible option, providing superior data precision and faster analysis, even for routine quality control laboratories. A common mobile phase consists of a mixture of water, methanol, and acetonitrile, acidified with phosphoric or formic acid. For industrial applications, a simple sample preparation method using an ultrasonic bath is ideal due to its ease of use and effectiveness. Additionally, heat treatment-based sample preparation provides a faster alternative to conventional, time-consuming extraction methods, making it highly suitable for routine quality control in the food manufacturing industry. This review covers literature published between 2001 and 2023. Following a thorough survey, nine articles were selected for detailed comparison.