Green non-conventional techniques for the extraction of polyphenols from agricultural food by-products: A review

Environmentally Friendly Techniques for the Recovery of Polyphenols from Food By-Products and Their Impact on Polyphenol Oxidase: A Critical Review

“…Moreover, a modifier could be used to improve the performance of the solvent. For instance, acetone can be added as a modifier to methanol in the extraction of curcumin from Curcuma longa using MAE [24]. Furthermore, room-temperature ionic liquids are becoming one of the most attractive solvent modifiers in the extraction process due to their outstanding solvent properties.…”

“…Since high pressure is applied in this process, the temperature could exceed the boiling point of the solvent. Indeed, the high pressure, ranging from 8 to 15 MPa, maintains the solvent in the liquid state [24]. This allows improved solubility and mass transfer between the food matrix and the solvent, leading to better extraction of polyphenols.…”

“…However, there is a large challenge regarding the efficient extraction of polyphenols from food by-products, since conventional extraction methods consume plenty of time and require a relatively large amount of solvent and energy. Indeed, extract quality, extraction rate, final cost, extraction yield, consumer, and environmental protection are some determining factors in choosing the more useful technology for recovering polyphenolic compounds [24]. Another challenge is to prevent climate change caused by the emission of heat from different industries [25].…”

Composition analysis and antioxidant activity evaluation of a high purity oligomeric procyanidin prepared from sea buckthorn by a green method

“…In recent years, procyanidins found in the berries of sea buckthorn have attracted the interest of researchers due to their unique biological activity, beneficial potency, and low toxicity ( Tkacz et al, 2021 ; Wang et al, 2020 ). According to available reports, methanol or ethanol were mainly used as solvents in the extraction of procyanidins ( Pagano et al, 2021 ). These organic solvents had several disadvantages in industrial production, such as being highly toxic, flammable, harmful to the environment, and their low boiling point, which contradicts green production ( Ruesgas-Ramón et al, 2017 ).…”

Editorial: Exploration of Underutilized Food Sources and By-products to Reduce Food Losses and Waste

“…Agricultural by-products have been traditionally used for animal feed, production of energy, and fuel, although by-products present some drawbacks such as lack of homogeneity due to different types and origin, biological instability, high Chemical Oxygen Demand (COD), and Biochemical Oxygen Demand (BOD). The heterogeneous chemical composition of by-products has catalyzed numerous studies to explore the potential of bioactive compounds for other sectors, such as the pharmaceutical, cosmetic, and nutraceutical industries ( 3 ).…”