The properties of the cocoa bean husk

The nutritional content and conferred health qualities, such as antihypertensive, antidiabetogenic, and antioxidant effects, of any meal or beverage, could be increased by including cocoa bean hulls as an ingredient.

The properties of the cocoa bean husk
What makes cocoa bean husks special? Photo by Rodrigo Flores / Unsplash

A study conducted at the Center for Research in Food and Development (CIAD) found that cocoa bean hulls could be used in the development of functional foods as they have potential antihypertensive, antidiabetogenic and antioxidant properties.

Cocoa bean hulls are a by-product derived from the post-harvest processing of cocoa beans. It is currently used mainly for livestock feed and fertilizer production. There are two main kinds: conventional and processed. With conventional, the cocoa bean is fermented by hand, while with processed, the bean is only washed and dried in the sun.

According to data from the Ministry of Agriculture and Rural Development (2021), approximately 3,531 tons of husk are produced each year as a result of the production of 29,429 tons of cocoa beans. The husk constitutes approximately 12% of the weight of the cocoa bean.

Cocoa bean hulls have been used to feed animals and as an ingredient, but they haven't been used to their full potential because they haven't been looked at as a possible source of bioactive components like peptides, which are chains of amino acids that can be made when enzymes break down proteins and may have bioactive properties.

As part of his academic training as a master of science at CIAD, Wilver Ernesto Vargas Lucero conducted research to evaluate the potential antihypertensive, antidiabetic, and antioxidant effects of cocoa bean husks.

Under the academic direction of emeritus research professor Belinda Vallejo Galland, from the Coordination of Food Technology of Animal Origin of CIAD, the student characterized physicochemically the samples of fermented and processed cocoa bean hulls. He then evaluated the degree of hydrolysis of the proteins using the abundance of free amino groups and performed an analysis of peptide abundance using the reverse phase liquid chromatography technique.

After different tests, the inhibition of angiotensin-converting and dipeptidyl peptidase enzymes and the antioxidant activity of the samples were measured before and after they were put through a simulated gastrointestinal digestion model and an ex vivo absorption model using the inverted intestine technique.

The results showed that both cocoa bean hulls presented inhibitions of the mentioned enzymes and antioxidant capacity after being subjected to digestion and absorption. The latter is of utmost importance, since to his knowledge, Vargas Lucero explained, this is the first study to report the bioaccessibility and stability of potentially bioactive peptides derived from cocoa bean hulls using DGS and ex vivo absorption models.

Based on the findings, Vargas Lucero added that cocoa bean hulls are a good source of bioactive peptides, polyphenols, and fiber, so they could be used as an ingredient in any food or beverage to enhance their nutritional value and confer beneficial health properties, such as antihypertensive, antidiabetogenic, and antioxidant effects.

Finally, Vargas Lucero commented that, if he had the opportunity to extend the scope of this research to the next stage, he would like to confirm the antihypertensive, antidiabetogenic, and antioxidant effects of cocoa bean hulls in vivo models, in addition to incorporating them as an ingredient in a food matrix and studying their functional properties.