A fast semi-quantitative screening for cocoa content in chocolates using MALDI-MSI

Chocolate is a popular food bearing a number of different classifications that are differentiated by proportions of cocoa solids, milk and cocoa butter. Literature brings evidence that chocolates with a high percentage of cocoa solids contribute to good health maintenance due to the presence of phenolic compounds. On the other hand, it is known that the productive process, including pre-processing, may influence the level of these substances in the finished product. Thus, accurate strategies to measure the levels of this class of molecules that can be highly adaptable throughout the manufacturing process are important to ensure high-quality products. Mass spectrometry is an analytical tool of high sensitivity and specificity that is leading the research in food analysis towards new directions. By using mass spectrometry imaging in direct food analysis, this contribution developed an effective methodology for comparatively establishing the levels of catechin/epicatechin as phenolics content markers for cocoa content in a series of commercial chocolates from a single manufacturer, rendering a versatile tool that can be applied in fast screening of cocoa content in finished products and during manufacturing.