Abstract
This study aimed to investigate the performance of accelerated solvent extraction (ASE) as a green approach for the recovery of polyphenols and pigments from wild nettle leaves (NL). ASE was operated at different temperatures (20, 50, 80 and 110 °C), static times (5 and 10 min) and cycle numbers (1–4) using ethanol (96%) as an extraction solvent. In order to compare the efficiency of ASE, ultrasound assisted extraction (UAE) at 80 °C for 30 min was performed as a referent. Polyphenol and pigment analyses were carried out by HPLC and antioxidant capacity was assessed by ORAC. Seven polyphenols from subclasses of hydroxycinnamic acids and flavonoids, along with chlorophylls a and b and their derivatives and six carotenoids and their derivatives were identified and quantified. Chlorogenic acid was the most abundant polyphenol and chlorophyll a represented the dominant pigment. ASE conditions at 110 °C/10 min/3 or 4 cycles proved to be the optimal for achieving the highest yields of analyzed compounds. In comparison with UAE, ASE showed better performance in terms of yields and antioxidants recovery, hence delivering extract with 60% higher antioxidant capacity. Finally, the potential of NL as a functional ingredient from natural sources can be successfully accessed by ASE.
Highlights
IntroductionNettle (Urtica dioica L.) is a herbaceous and perennial wild plant for which numerous studies show that almost every part of it (stem, flowers, leaves, roots and seeds) has a significant content of various bioactive compounds with corresponding antioxidant capacity (polyphenols, carotenoids, chlorophyll, phytosterols, etc.) [1,2,3]
Nettle (Urtica dioica L.) is a herbaceous and perennial wild plant for which numerous studies show that almost every part of it has a significant content of various bioactive compounds with corresponding antioxidant capacity [1,2,3]
Present study involved the optimization of the Accelerated Solvent Extraction (ASE) operating conditions in terms of temperature (20, 50, 80 and 110 ◦ C), static time (5 and 10 min) and number of extraction cycles (1–4) for nettle leaves (NL) polyphenols and pigments extraction
Summary
Nettle (Urtica dioica L.) is a herbaceous and perennial wild plant for which numerous studies show that almost every part of it (stem, flowers, leaves, roots and seeds) has a significant content of various bioactive compounds with corresponding antioxidant capacity (polyphenols, carotenoids, chlorophyll, phytosterols, etc.) [1,2,3]. Different parts of this plant may have different applications for functional food production due to its valuable nutritional and biological composition [4,5,6,7]. Consumer preferences are driving rapidly towards the natural products, the interest of the industry in the production and application of natural extracts is constantly growing. Processes 2020, 8, 803 as they show multiple benefits and could represent a valuable ingredient of functional foods, foods supplements and nutraceuticals [17,18]. Nettle extracts are the most common form of its application in the industry, where for each individual species, as well as its part, optimal extraction conditions should be determined with an emphasis on maximum process efficiency and selective isolation of target compounds [19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
