Biological Properties of Polyphenols Extracts from Agro Industry’s Wastes

Purpose: Processing and selection of fruits and vegetables generate high amounts of wastes that represent an economical and environmental issue for the agroindustry sector. Nevertheless, according to so called “biorefinery” approach, this waste biomass can be exploited for the recovery of value added molecules. In this paper the residues of industrial processing of fennels, carrots, lemons and tomatoes were used as sources of polyphenols. Methods: In order to optimize the recovery of polyphenols, different extraction techniques (maceration, ultrasound and microwave assisted extraction) were used in combination with different extraction media (water, ethanol, methanol and their mixtures). The polyphenols’ fractions were tested for their chemical and biological properties. Results: All the obtained phenol fractions showed high antioxidant power and scavenging ability towards stable radical species and hydrogen peroxide. Moreover, the isolated polyphenol mixtures (containing remarkable compounds like quercetin, kaempferol, naringin, hesperetin) also displayed potential activities as anti-cancer, anti-microbial and acetylcholinesterase inhibiting agents. Conclusions: Overall the obtained results showed that the residual matter produced by the industrial processing of fruits and vegetables contain high amounts of polyphenols. These polyphenolic fractions still retain their biological and antioxidant properties and therefore could be further exploited for other industrial applications.