Supercritical Fluid Extraction of Fat and Caffeine with Theobromine Retention in the Cocoa Shell

Abstract

The cocoa shell is a residue of low commercial value, which represents an alternative for obtaining substances of added value for the food and pharmaceutical industry. Substances of interest in the shell include fat and methylxanthines (theobromine and caffeine). In order to obtain the extraction behavior with supercritical CO2, a 23 factorial design was proposed with six central points, taking dynamic extraction into consideration. The following factors were involved: pressure (2,000–6,000 psi), temperature (313–333 K), and time (30–90 min). The obtained yield was between 3.66% and 15.30%. Fat was the substance that was extracted most effectively (94.73%). Caffeine demonstrated variability in the residue, with at least six treatments that exceeded a removal rate of more than 90%, while it was practically impossible to extract theobromine. The difference with regard to the extraction of theobromine may be attributed to its low solubility. Characterization using FT–IR showed the modifications before and after the process, providing clear evidence of the changes corresponding to the fat at 2,924, 2,854 and 1,745 cm−1. The results presented establish the basis for the extraction of substances such as fats and methylxanthines from a cocoa shell with the use of CO2.

Cocoa Bean Shell—A By-Product with Nutritional Properties and Biofunctional Potential

“…The fat content accounts for 1.50%-8.49% of dried CBS and is therefore considered a minor component of the by-product when compared to the approximate 50% fat content in cocoa beans [27]. However, the fat in CBS has also received interest from researchers that have optimized methods for its extraction [71]. As reported for the protein content, the roasting process could also entail a decrease of about 36% of the fat in CBS [26].…”

Bioactive Compounds from Cocoa Husk: Extraction, Analysis and Applications in Food Production Chain

“…Fat and methylxanthines (theobromine and caffeine) were extracted from cocoa shells using supercritical CO 2 [23]. Pressure (2000-6000 psi), temperature (313-333 K), and time (30-90 min) were varied to obtain the optimum extraction condition.…”

A Review of Innovation in Cocoa Bean Processing By-Products

“…Roasting reduces fat content in cocoa bean skin. Some of the fatty acids found in cocoa bean shells include oleic, palmitate, capric, and stearic acids [67]. Cocoa bean shells are also high in antioxidants.…”