Optimization of the process of obtaining an aqueous extract of cocoa husk

Abstract

The cocoa husk is a by-product of the cocoa industry with a high content of phytochemical and nutritional compounds. It has a typical chocolate flavor and smell that can be used in the production of food products. As a general objective, it was proposed to optimize the process for obtaining the infusion type aqueous extract from the husk of the roasted cocoa bean. A micromorphological and microbiological evaluation of the scale was carried out. Then the experiment was designed (11 experimental runs) where the best infusion type extract was selected taking into account the variables sensory quality and total polyphenol content, using the response surface methodology. The main results were that the cocoa husk presents different structural characters: cavities or pockets of fat or oils, different types of vessels, sclerenchymal and sclereid fibers, reserve parenchyma with pentagonal cells, presence of proteins and starch grains. The performance optimization obtained quadratic models that described the behavior of the sensory quality, the total content of polyphenols and the best conditions for obtaining them (0.1 g/mL). The negative correlation between the total polyphenol variables and sensory quality was verified, fulfilling from the relation 0.08 with a higher intensity. The selected infusion presented 2.3% of total solids, acceptable sensory quality, total polyphenols of 1098.3 mg (AGE)/L of extract and chromatic coordinates that correspond to a medium brown color. This study constitutes the basis for expanding the application of this by-product in food production.