Pistacia vera L. leaves as a renewable source of bioactive compounds via microwave assisted extraction

• Published in: Sustainable chemistry and pharmacy 2022-10, Vol.29, p.100815, Article 100815
• Main Authors: Elakremi, Manel, Sillero, Leyre, Ayed, Lazher, ben Mosbah, Mongi, Labidi, Jalel, ben Salem, Ridha, Moussaoui, Younes
• Format: Article
• Language: English
• Subjects: Antimicrobial; Antioxidant; Leaves; Microwave assisted extraction; Phenolic compounds
• ISSN: 2352-5541; 2352-5541
• DOI: 10.1016/j.scp.2022.100815

The production of pistachio in Tunisia generates a large amount of potentially valuable waste, such as leaves, that could be used as source of bioactive compounds. In this work, the extraction of phytochemicals from Pistacia vera L. leaves (male and female) by microwave-assisted extraction (MAE) has been investigated. A response surface methodology (RSM) was used for the optimization of bioactive compounds extraction, where the independent variables were temperature and extraction time, and the dependent variable was extraction yield. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS, and FRAP) and antimicrobial activity of the extracts obtained at optimal conditions for both leaves were evaluated and compared not only between them, but also with the extracts obtained by maceration. The optimum extraction conditions were 70 °C and 61 °C, and 5.6 and 12 min for male and female leaves respectivily. The best results were achieved for female leaves by MAE with 36% of extraction yield, TPC of 196.35 mg gallic acid equivalents (GAE)/g dry weight (DW), TFC of 83.34 mg catechin equivalents (CE)/g dry weight (DW), and high antioxidant and antimicrobial activities. The evaluation of biological activity of the extracts showed that MAE provides extracts with better antioxidant and antimicrobial capacities then those obtained by maceration. Moreover, UPLC-DAD-ESI-MS was performed to confirm the presence of some phenolic compounds in MAE extracts, such as quercetin, apigenin and myricetin derivatives. The results revealed that MAE is an efficient technique for the extraction of active components from Pistacia vera L. leaves. [Display omitted] •Pistacia vera L. leaves have been confirmed as a source of biomolecules.•MAE of Pistacia vera L. male and female leaves have been successfully optimized.•MAE improved extraction yield and reduced extraction time compared to maceration.•MAE extracts had high phenolic and flavonoid content, e.g. quercetin derivatives.•The ability of extracts as natural preservative against pathogens is proven.