Pulsed Electric Field Assisted Extraction of Bioactive Compounds from Cocoa Bean Shell and Coffee Silverskin

The present study focused on the application of pulsed electric fields (PEF) as an innovative pre-treatment technique to improve the recovery of polyphenols from two food by-products, cocoa bean shell (CBS) and coffee silver skin (CS). The effect of the different operating parameters on the extraction of polyphenols was optimised using the response surface methodology statistical approach. The optimised methodology was compared with conventional extraction and applied to several CBS and CS samples to classify the samples according to origin, variety and industrial treatment. PEF-assisted extraction had higher (approximately 20%) recovery yields of polyphenols and methylxanthines than conventional extraction. Finally, the results highlighted that the composition of bioactive compounds from different extracts of CBS and CS and their antioxidant properties depended on the origin, variety and industrial processing of the raw material. These by-products may be a promising source of natural compounds, with potential applications on food and health sectors.