Determination of fat contents with supercritical co2 extraction in two commercial powder chocolate products: comparison with np‐1719

Fat content is an important variable in chocolate and cocoa powder production. Current Association of Official Analytical Chemists‐approved methods may require up to 18 h for determination of fat content data, like Portuguese Norma, NP ‐1719. Supercritical carbon dioxide (SC‐CO2) extraction of fats from chocolate products eliminates solvent and solvent disposal costs and exposure to hazardous reagents. SC‐CO2 fluid extraction of extracts from samples of commercial powder milk chocolate, 5–6 g, was carried out in a modified commercial flow apparatus, at temperatures from 313.15 to 353.15 K, pressures up to 60.0 MPa and flow rates from 0.16 kg/h to 0.47 kg/h of CO2. Percent fat values were determined gravimetrically by collecting the extract into a preweighed trap. Recoveries using a 20‐ to 25‐min supercritical fluid extraction method were between 98 and 100% of NP‐1719 values with standard deviations on replicates ranging from 0.4 to 0.6%. The main compounds identified in the extracts were palmitic acid (28–30%), stearic acid (30–33%), oleic acid (29–30%) and linoleic acid (2–4%). The possibility of replacement of NP‐1719 method by a SC‐CO2 extraction was demonstrated. PRACTICAL APPLICATIONS: Carbon dioxide is the most used supercritical solvent for application in the food and related industries (mainly because it is noninflammable, cheap and nontoxic). With this solvent, it is possible to obtain solvent‐free extracts and to avoid the degradation of thermally labile components; therefore, the natural odor and aroma of the starting material are retained. The operational optimization studies and the important properties of the extracts expected to be present are lines of research. In this case study, with applications to the industry as analytical technique, we can improve the time required to determine the total fat content and characterize the components present in two different commercial powder chocolate products.