Recovery and Purification of Antioxidant Compounds from Plant Origin Agro-Industrial By-products

Abstract

The plant origin materials have long been an important source of antioxidant compounds having both health and technological benefits. The increasing production brings about an immense disposal rates of the agro-food by-products including husk, bran, seed, stem, leaf, and peel residues that should be recovered as considering economic and environmental issues. These plant-based by-products generally contain even higher concentrations of antioxidant constituents compared to edible parts. However, the recovery of value-added compounds from the by-products of plant sources is challenging due to their lignocellulosic cellular structures. Therefore, scientific studies have intensively focused on the novel extraction protocols along with additional purification steps, e.g., membrane separation via ultrafiltration and diafiltration, especially in the last 10 years. The novel and often referred as green extraction techniques include deep eutectic solvent, ultrasound- and microwave-assisted extraction, etc. Optimization of process variables is also highly effective on the final product quality as well as the recovery yield and energy/solvent consumption. The functional food market is estimated to reach 275 billion US dollars within the next 5 years. Among this widespread portfolio, antioxidant fortified products have an important place in terms of economic benefits so integration of eco-friendly, high-efficient, and low-cost novel techniques into the commercial applications on the recovery of antioxidant compounds should be extended.