The study, published in the Journal of Food Science, outlines a method for an enzymatic treatment for poor-quality cocoa almonds (known as slate), which may result in a better chocolate flavour.
“This result is very encouraging because it indicates that microbial enzymes, which are cheaper and more readily available than animal enzymes, can be used to enhance chocolate flavour,” said the authors, led by Hilana Salete Silva Oliveira from State University of Feira de Santana (UEFS), Brazil.
They added that further optimisation of the enzyme treatment is necessary “to obtain better results and thus establish a process that can be used for industrial purposes for manufacturing cocoa and chocolate.”
Cocoa almonds are the raw material used in the production of chocolate. They are fermented and dried seeds of cocoa fruits.
The authors noted that the commercial value of cocoa is based not only on the melting characteristics of its fat, which melts in very narrow range that is close to body temperature and provides a unique mouth-feel, but also on the chocolate flavour, “which is developed in properly processed seeds.”
They noted that fresh beans, extracted from the ripe cocoa fruit, have no chocolate flavour and are in fact “extremely bitter and astringent.”
“For the desired flavour to develop, the seeds must go through a curing process that involves a stage of fermentation and drying, which leads to the formation of flavour precursors,” explained Oliveira and her colleagues.
However, they said that a “recurring problem” in the chocolate industry is the poor quality of the some almonds, which leads to reduced fermentation and poor flavour formation.
“Because the fermentation and drying processes still take place on farms, without any controlled condition, a significant percentage of cocoa almonds from each batch do not undergo the necessary changes (acidification and temperature increase) for the necessary enzymatic reactions to occur,” said the researchers.
“As a result, a significant portion of the roasted almonds do not develop the characteristic chocolate flavour, which reduces the quality of the chocolate produced,” they added.
Oliveira and co-workers said that one possibility to remedy this problem is the use of commercial enzymes with similar activity patterns to help in the fermentation process.
“These enzymes should hydrolyze proteins present in the almonds, releasing the flavour precursors that were not produced during the fermentation period … Thus, it would be possible to standardize the quality of cocoa produced, ensuring the quality of the chocolate,” said the authors.
The researchers tested three commercial enzymes for their ability to improve the flavour attributes of cocoa slate. The team tested swine pepsin, carboxypeptidase A (purchased from the Sigma-Aldrich), and Flavorzyme (Novozymes), against enzymes extracted from unfermented cocoa beans (vegetable enzyme).
The enzymatic treatments were evaluated by chemical analysis (hydrolysis efficiency), and sensory analysis of the treated material compared to good-quality cocoa almonds.
The researchers reported that almonds treated with microbial enzymes (Flavorzyme) developed better chocolate flavour. They added that Flavorzyme, which contains aspartic proteases and carboxypeptidases of microbial origin, provided an improvement of 50 per cent in relation to the chocolate flavour.
“Although the hydrolysis achieved was similar for all tested enzymes … microbial enzymes were able to produce more of the desired precursors that, after roasting, lead to the formation of the chocolate flavour,” said the authors.
“These results indicate that it is possible to use microbial enzymes to improve the quality of cocoa almonds, which is advantageous because microbial enzymes are low in cost and can be supplied in significant quantities, making them more viable for industrial applications,” concluded Oliveira and colleagues.
Source: Journal of Food Science