| Abstract
| - Mashua (Tropaeolum tuberosum Ruíz and Pavón), an Andean tuber with high antioxidant activity,has sparked interest because of its traditional medicinal use. In this study, we evaluated theanthocyanin composition for three purple mashua genotypes and their contribution to the overallantioxidant activity of the tuber. Mashua anthocyanins, total phenolics, and 2,2‘-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) antioxidant activity ranged from 45.5 to 131.9 mg ofcyanidin 3-glucoside equivalents/100 g fresh weight (FW), 174.9 to 275.5 mg of gallic acid equivalents/100 g of FW, and 16.2 to 45.7 μmol of Trolox equivalents/g of FW, respectively. The high-performanceliquid chromatography with photodiode array detection (HPLC−DAD) and HPLC−electrosprayionization tandem mass spectrometry (ESI/MS−MS) profiles revealed the presence of 11 differentanthocyanins. The two major pigments (56.4−73.0% total area range at 520 nm) were identified asdelphinidin 3-glucoside-5-acetylrhamnoside and delphinidin 3-sophoroside-5-acetylrhamnoside. Otherpigments were delphinidin 3-glucoside-5-rhamnoside, delphinidin 3-sophoroside-5-rhamnoside, delphinidin 3-glucoside, cyanidin 3-sophoroside, and cyanidin 3-sophoroside-5-rhamnoside. Cyanidin3-glucoside and cyanidin 3-rutinoside were only found in two genotypes, while pelargonidin3-sophoroside and pelargonidin 3-sophoroside-5-rhamnoside were only found in the third one.Anthocyanins from mashua were the major contributors to the total ABTS values for only one of thethree genotypes, suggesting that other phenolics present are playing a major role in the antioxidantpower of mashua tubers. Results from this study provide important information for the Nutraceuticaland Functional Food Market for the use of mashua anthocyanins not only as a source of naturalcolorants but also as a source of phytonutrients. Keywords: Mashua; anthocyanins; Tropaeolum tuberosum; antioxidant activity; HPLC−DAD; HPLC−ESI/MS−MS; total phenolics
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