Antioxidant capacity and secondary metabolites in four species of Andean tuber crops: native potato (Solanum sp.), mashua (Tropaeolum tuberosum Ruiz & Pavón), Oca (Oxalis tuberosa Molina) and ulluco (Ullucus tuberosus Caldas)
Antioxidant Profiling of Native Andean Potato Tubers (Solanum tuberosum L.) Reveals Cultivars with High Levels of β-Carotene, α-Tocopherol, Chlorogenic Acid, and Petanin