Phytochemical Profile and Antioxidant Activity of the Tuber and Peel of Pachyrhizus erosus

This study systematically investigated the antioxidant activities and phytochemical profiles of petroleum ether (PE), ethyl acetate (EtOAc), n-butanol (n-BuOH) and aqueous fractions of edible (tubers) and non-edible portions (peels) ofPachyrhizus erosus.The results showed that both the tubers and peels fromP. erosuswere rich in polyphenols and flavonoids, whereas the EtOAc fraction of peels had the highest polyphenol content, and the PE fraction of peels had the highest total flavonoid content. ABTS, DPPH, and FRAP assays revealed that both the EtOAc fraction of tubers and peels fromP. erosusshowed significant antioxidant activity, whereas the EtOAc fraction of peels possessed better antioxidant activity than that of tubers. UPLC-Orbitrap-MS/MS analysis indicated that thirty compounds were identified from the EtOAc fractions of peels and tubers, including twenty-one flavonoids, six phenolics, two coumarins, and one lignan, some of which have previously been revealed to display significant antioxidant and anti-inflammatory effects via the Nrf2-Keap1 and NF-κB signaling pathways. These findings provide robust scientific evidence for the health-promoting properties and pharmaceutical potential ofP. erosus, and its non-edible portion (peels) has great potential for use as a natural antioxidant in the food, cosmetic, and pharmaceutical industries.