Fermentation and Roasting Enhance Cocoa’s Health Benefits

Processing of foods can reduce their health benefits, but that is not always the case. A recent Penn State University study on cocoa showed that processing can increase the health benefits of chocolate!

Polyphenols are a large and diverse group of naturally occurring compounds found in many plant-based foods. They are associated with numerous health benefits, including reduced risk of chronic diseases such as heart disease, cancer, and neurodegenerative disorders. There are several types of polyphenols, which can be classified based on their chemical structure. Some of the most common types include flavonoids (which includes subclasses such as flavanols, flavonols, and anthocyanins), phenolic acids, stilbenes, and lignans. Each type of polyphenol has unique properties and health benefits, and different foods contain varying amounts of each type.

Cocoa is a rich source of polyphenols and the most abundant include flavan-3-ol monomers (e.g., epicatechin and catechin) and polymers (e.g., proanthocyanidins). Many studies have reported beneficial health effects of cocoa intake including improvement of chronic inflammation, vascular function, and others. To make chocolate, cocoa beans typically undergo fermentation and roasting to develop desirable flavor and aroma compounds. These processes can affect cocoa polyphenol content – both fermentation and roasting have been shown to decrease total polyphenol and total flavan-3-ol concentration (especially monomers). However, we are learning that these monomers are not ‘lost’. Instead, they are polymerized and play an important role in the gut health via the microbiome.

A recent mouse study compared the effect of different fermentation and roasting procedures on the ability of cocoa to improve health (obesity, gut barrier dysfunction and chronic inflammation). They found that some of the most processed samples had the largest positive impact (reduced body weight gain, reduced gut permeability, improved gut microbiome). Processing reduced the polyphenolic content in the cocoa, but the composition of polyphenolic compounds that remained shifted to more of what the researchers suspect to be the most effective polyphenols.

This data demonstrated strong protective efficacy from cocoa supplementation, especially for the more processed cocoa samples. Overall, the anti-obesity and anti-inflammatory benefit of cocoa was resilient to changes induced by fermentation or roasting. The mechanisms are not well understood, but is likely multifactorial involving digestive physiology, enzymes, and microbiota.