Proximal characteristics, phenolic compounds profile, and functional properties of Ullucus tuberosus and Arracacia xanthorrhiza

Aim: The Andean tubers Ullucus tuberosus and Arracacia xanthorrhiza are of great international importance due to their nutritional value (carbohydrates, fiber), functional and phenolic compounds. This study aimed to determine the proximate composition of the flours of these tubers, their functional properties, and the phenolic profiles of both the skin and the pulp, since the flour used is a mixture of both. Methods: The proximal characteristics were determined as established by the Association of Official Analytical Chemists (AOAC), the functional properties, water holding capacity (WHC), swelling capacity (SC), and oil holding capacity (OHC); and the profile of phenolic compounds was carried out by high performance liquid chromatography-mass spectrometry (HPLC-MS). Results: Results revealed that the tubers contain more than 50% carbohydrates, with U. tuberosus having 14% fiber and A. xanthorrhiza having 4.07% fiber. Notably, they are rich in minerals, such as potassium (K), with levels of 4.12% and 3.32% for U. tuberosus and A. xanthorrhiza, respectively. In terms of functional properties, U. tuberosus exhibited a WHC of 0.78 g water/g dry matter (DM), an SC of 1.42 g water/g DM, and an OHC of 0.44 g oil/g DM. In contrast, A. xanthorrhiza showed a WHC of 0.96 g water/g DM, an SC of 3.86 g water/g DM, and an OHC of 0.18 g oil/g DM. Additionally, the study identified various hydroxycinnamic acids, including caffeic acid 4-O-glucoside and p-coumaroyl glucose, as well as methoxyflavonols, such as 3,7-dimethylquercetin. Conclusions: These characteristics suggest that the flours could be valuable for the production of bakery products, pastries, pastas, or foods requiring high viscosity. Furthermore, U. tuberosus and A. xanthorrhiza flours have potential applications in the development of functional foods, thus promoting their use and adding value to these tubers produced in the Andean region.