## Editorial \"High-Performance Green Extraction of Natural Products\"  
### [PERSON]  
Green Processes & Biorefinery Group, Department of Food Science & Nutrition, University of Thessaly, N. Temponera Street, 43100 Karditsa, Greece; [EMAIL_ADDRESS]  
Received: 21 October 2020; Accepted: 28 October 2020; Published: 30 October 2020  
There has been, to-date, a large number of studies pertaining to the exploitation of plant resources (herbs, botanicals, processing by-products) for the production of extracts enriched with bioactive substances. The interest has been focused on the development of efficient and cost-effective downstream processes, which aim at producing commodities on the basis of either crude or purified extracts. Traditional extraction techniques, including percolation, decoction/infusion generation, maceration, etc., are currently being replaced by cutting-edge, sophisticated technologies with higher efficiency and selectivity, and a more eco-friendly profile. Advanced extraction methodologies based on ultrasonication, microwaves, pulsed electric fields, high voltage discharges, enzymes, pressurized liquids, supercritical fluids, deep eutectic solvents, etc., have in many instances proven to be more targeted, high-performing, straightforward, fast, sustainable, fully automated, and with relatively low capital cost. This Special Issue addresses the concept of innovative and emerging strategies that aim at effectively implementing green technologies for the extraction of bioactive compounds from plant resources. [PERSON] et al. [1] examined the extraction of caffeine and chlorogenic acids from coffee pulp, a by-product of coffee production, using aqueous solutions of \(\beta\)-cyclodextrintrin (\(\beta\)-CD) as a non-conventional solvent. The parameters of \(\beta\)-CD concentration, liquid-to-solid ratio, and temperature were evaluated based on the antiradical activity and the caffeine content, by deploying the response surface methodology. The sensory profiles of brews prepared with coffee and coffee pulp with or without cyclodextrin were studied with quantitative descriptive analysis. The brew from the by-product had fruity, botanic, sweet, and sour sensory properties, and cyclodextrin was found to be able to affect the overall taste of the brew. [PERSON] et al. [2] investigated the exploitation of deep eutectic solvents (DESs) (choline chloride: citric acid and choline chloride: glucose) as solvents for extracting valuable phenolic antioxidants from grapes. Investigation was conducted on ten grape varieties, observing seeds and skin as different matrices. Overall results support that DESs (particularly choline chloride: citric acid) were comparable to conventional solvents, and in most cases even outperformed acidified aqueous ethanol with regard to extraction efficiency and antioxidant activity. Regardless of varietal distinctions, grape seeds were found to have higher antioxidant capacity compared to grape skins, in accordance with their polyphenol concentrations. [PERSON] et al. [3] developed a simple, straightforward, and green extraction methodology to effectively recover potato peel polyphenols, using hydroxypropyl \(\beta\)-cyclodextrintrin (HP-\(\beta\)-CD). After an initial assay to identify the optimal HP-\(\beta\)-CD concentration that would provide increased extraction yield, optimization based on response surface methodology enabled maximization of the extraction performance. Testing of temperatures higher than 30 \({}^{\circ}\)C and up to 80 \({}^{\circ}\)C did not favor higher yields. The extracts obtained with HP-\(\beta\)-CD were slightly richer in polyphenols than extracts prepared with conventional solvents, such as aqueous ethanol and methanol, displaying similar antioxidant characteristics. The major polyphenols that could be identified in the extracts wereneochlorogenic, chlorogenic, caffeic, and ferulic acids. The outcome of this study demonstrated that HP-\(\beta\)-CD may be used as a highly effective green means of recovering potato peel polyphenols, at near-ambient temperature.