Bioactive Phenolic Compounds From Agri-Food Wastes: An Update on Green and Sustainable Extraction Methodologies

Abstract

Phenolic compounds are broadly represented in plant kingdom, and their occurrence in easily accessible low-cost sources like wastes from agri-food processing have led in the last decade to an increase of interest in their recovery and further exploitation. Indeed, most of these compounds are endowed with beneficial properties to human health (e.g., in the prevention of cancer and cardiovascular diseases), that may be largely ascribed to their potent antioxidant and scavenging activity against reactive oxygen species generated in settings of oxidative stress and responsible for the onset of several inflammatory and degenerative diseases. Apart from their use as food supplements or as additives in functional foods, natural phenolic compounds have become increasingly attractive also from a technological point of view, due to their possible exploitation in materials science. Several extraction methodologies have been reported for the recovery of phenolic compounds from agri-food wastes mostly based on the use of organic solvents such as methanol, ethanol, or acetone. However, there is an increasing need for green and sustainable approaches leading to phenolic-rich extracts with low environmental impact. This review addresses the most promising and innovative methodologies for the recovery of functional phenolic compounds from waste materials that have appeared in the recent literature. In particular, extraction procedures based on the use of green technologies (supercritical fluid, microwaves, ultrasounds) as well as of green solvents such as deep eutectic solvents (DES) are surveyed.

Plant Secondary Metabolites: An Opportunity for Circular Economy

“…NADES and their perspectives in the agri-food sector were extensively reviewed by Mišan et al [ 206 ]. Regarding the employment of NADES in the extraction of plant-driven industrial wastes, they have been used to efficiently obtain phenols from by-products of the olive oil industry, and the onion, tomato, potato, orange, and pear canning industries [ 209 , 210 ].…”

Concept, mechanism, and applications of phenolic antioxidants in foods

“…Similarly, in germinated cereals and pulses, the classification, and metabolism of phenolic compounds were also recently reviewed (Bodoira & Maestri, 2020;Kumar & Pandey, 2020;Xu, Rao, & Chen, 2020). The phenolic compounds in agri-foods wastes and their extraction methodologies were reviewed by Panzella et al (2020). Durazzo et al (2019) recently reviewed the chemistry, occurrence, and health benefits of polyphenols.…”

COVID-19: Eco-friendly hand hygiene for human and environmental safety

“…Therefore, emerging extraction techniques such as microwave-assisted extraction, ultrasound-assisted extraction, supercritical fluid extraction, and pulsed electric field extraction are gaining interest. These emerging techniques are regarded as green and sustainable extraction techniques [ 53 , 54 ] and could make these plant-derived antimicrobial agents as viable ingredients in natural hand-sanitizers. However, it is important to look indigenous plants for the economic viability of plant-derived biosurfactants and other natural antimicrobials for their utilization as key ingredients in nature-based soaps and hand sanitizers.…”