Valorization of extracts of Andean roots and tubers and its byproducts: bioactive components and antioxidant activity in vitro

Andean roots and tubers are endemic crops and grow in South America, they have high levels of nutrients and bioactive components. This work aimed to determine the polyphenols, flavonoids, and anthocyanins contents in peels and pulps of Andean roots and tubers; to evaluate the antioxidant activity by 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) and to establish the correlations between the bioactive content, antioxidant methods and the antioxidant potency composite (APC) index. All trials were based on the absorbance measurements using UV-visible spectroscopy and the correlation coefficients were calculated using bivariate statistical methods. The results obtained show that the polyphenol content in pulps varied from 17.46 to 29.65 mg GAE/g, and in peels was from 14.18 to 28.37 mg GAE/g. The methods for testing antioxidant activity were presented in the following order: FRAP > ABTS > DPPH, the highest APC was for mashua peel, and the lowest APC was for ulluco pulp yellow. The correlations for the variables studied were moderate (0.3 < r < 0.7). In conclusion, it can be mentioned that the Andean roots and tubers can be used as a functional ingredient and medicinal from their pulps and peels.