Techniques and modeling of polyphenol extraction from food: a review.

There is a growing demand for vegetal food having health benefits such as improving the immune system. This is due in particular to the presence of polyphenols present in small amounts in many fruits, vegetables and functional foods. Extracting polyphenols is challenging because extraction techniques should not alter food quality. Here, we review technologies for extracting polyphenolic compounds from foods. Conventional techniques include percolation, decoction, heat reflux extraction, Soxhlet extraction and maceration, whereas advanced techniques are ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, high-voltage electric discharge, pulse electric field extraction and enzyme-assisted extraction. Advanced techniques are 32-36% more efficient with approximately 15 times less energy consumption and producing higher-quality extracts. Membrane separation and encapsulation appear promising to improve the sustainability of separating polyphenolic compounds. We present kinetic models and their influence on process parameters such as solvent type, solid and solvent ratio, temperature and particle size.