Quantification of PAH4 in roasted cocoa beans using QuEChERS and dispersive liquid-liquid micro-extraction (DLLME) coupled with HPLC-FLD.

Roasting is an important process in cocoa production which may lead to formation of non-desirable compounds such as polycyclic aromatic hydrocarbons (PAHs). Therefore, PAH4 (sum of four different polycyclic aromatic hydrocarbons; benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) in roasted cocoa beans was determined using a modified method (combination of QuEChERS and DLLME), and quantified by HPLC-FLD. The modified method was validated and met the performance criteria required by the EU Regulation (No. 836/2011). Results show a significant (p < 0.05) increase of PAH4 (0.19-7.73 ng/g) with an increase in temperatures (110-190 °C) and duration (10-50 min). The PAHs content in whole cocoa bean roasting was detected even at the lowest temperature (110 °C) compared to nib roasting detected at 150 °C which indicates that PAHs was transferred from dried shells to roasted cocoa beans during the roasting process. The data obtained may help to control and minimize PAH4 formation during cocoa processing.

Changes of Phytosterols, Rheology, Antioxidant Activity and Emulsion Stability of Salad Dressing with Cocoa Butter During Storage.

Addition of phytosterols and antioxidants to food may provide additional health benefits to consumers. Their stability in a food matrix may decrease during storage. Therefore, the objectives of this study are to formulate a salad dressing with cocoa butter and determine its phytosterol stability, antioxidant activity and physicochemical properties during storage. The cocoa butter was extracted using a supercritical CO2 extraction (green technology) and added to the formulated salad dressing (containing different ratios of cocoa butter and soybean oil). The salad dressing with 30% cocoa butter (the most stable emulsion) was selected for storage study at 4 and 30 °C. However, values of physicochemical parameters and mass fractions of phytosterols, total phenolic compounds (determined using Folin-Ciocalteu reagent) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) in the salad dressing with 30% cocoa butter decreased during storage (from day 0 to 28) and increased with the temperature increase, probably due to the oxidation of oil. Thus, the most desirable storage temperature for salad dressing was 4 °C. An excellent stability of the salad dressing with 30% cocoa butter at different storage temperatures for 28 days offers a potential application in food industries for production of salad dressing with cocoa butter enriched with phytosterols.