Phenolic profiles and antioxidant activity of Morus alba L. infusions prepared from commercially available products and naturally collected leaves

The aim of this study was to compare the phenolic compound content and antioxidant activity of infusions made from commercially available Morus alba L. leaves with those of infusions made from a naturally collected source. The phenolic profile was determined using RP-HPLC-DAD and LC-Q-TOF-MS/MS. The total phenolic content (TPC) was determined using Folin-Ciocâlteu reagent. To assess the antioxidant and reducing properties, Trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP) were used. Our analysis revealed the presence of two phenolic acids and six flavonoids. The most abundant compound was chlorogenic acid. The TPC, TEAC, and FRAP results indicated that infusions prepared from naturally collected samples exhibited greater phenolic content (19.7-52.6 vs 18.1-35.2 mg/100 ml) and stronger antioxidant (0.0605-0.1842 vs 0.0453-0.0822 mmol Trolox/100 ml) and reducing (0.244-0.597 vs 0.202-0.371 mmol Fe²⁺/100 ml) activities than those of commercially available products in the Polish market. Samples L1-L3 from the natural collection were those with the highest values. These results were further supported by principal component analysis (PCA), which categorized observations into three distinct clusters.