In this work, the phenolic compounds of four Andean tubers grown in Ecuador, such as yacon (Smallantus
sonchifolius), mashua (Tropaeolum tuberosum), melloco (Ullucus tuberosus) and purple-sweet potato (Ipomea batatas)
were analyzed by HPLC–DAD–ESI/MSn. Non-flavonoid compounds, such as hydroxycinnamic derivatives
were identified in yacon, purple sweet potato and melloco samples, accounting for 100, 26 and 15% of the total
of phenolic compounds, respectively. Mashua sample revealed the presence of flavan-3-ol monomers that were
not found in the other samples, being (-)-epicatechin the most abundant (9.22 μg/g DM). Quercetin-3-O-rutinoside
(40.6 μg/g DM), kaempferol-O-dirhamnosil-hexoside (29.5 μg/g DM) and kaempferol-O-dihexoside
(46.22 μg/g DM) were the main flavonols present in mashua, melloco and purple sweet potato, respectively,
being this last specie which presented the highest concentration in flavonols (89.32 μg/g DM). Purple sweet
potato also had anthocyanins (157.16 μg/g DM), not detected in the other samples. The presence of these
compounds and the consideration of the total phenolic content suggest the use of these Andean tubers as promising
sources of natural antioxidants of wide use in the food industry. Therefore, these tubers could be considered
as novel and inexpensive sources of bioactive compounds for their potential use in functional foods and
nutraceuticals.
