Find in Library

In recent years, agricultural and industrial residues have attracted a lot of interest in the recovery of phytochemicals used in the food, pharmaceutical, and cosmetic industries. In this paper, a study on the recovery of phenol compounds from <i>Lycium</i> spp. leaves is presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been used with alcoholic and hydroalcoholic solvents. Methanolic UAE was the most successful technique for extracting phenols from <i>Lycium</i> leaves, and we used on leaves from <i>L. barbarum</i> and <i>L. chinense</i> cultivated in Italy. The extracts were then characterized as regards to the antioxidant properties by in vitro assays and the phenol profiling by a high performance liquid chromatography-diode array detector (HPLC-DAD). Chlorogenic acid and rutin were the main phenol compounds, but considerable differences have been observed between the samples of the two <i>Lycium</i> species. For example, cryptochlorogenic acid was found only in <i>L. barbarum</i> samples, while quercetin-3-O-rutinoside-7-O-glucoside and quercetin-3-O-sophoroside-7-O-rhamnoside only in <i>L. chinense</i> leaves. Finally, multivariate statistical analysis techniques applied to the phenol content allowed us to differentiate samples from different <i>Lycium</i> spp. The results of this study confirm that the extraction is a crucial step in the analytical procedure and show that <i>Lycium</i> leaves represent an interesting source of antioxidant compounds, with potential use in the nutraceutical field.