Chemical profile of colorful bean (Phaseolus vulgaris L) flours: Changes influenced by the cooking method.

Abstract

This study aimed to determine how the cooking methods change the phenolics and saponins profiles, oligosaccharides, antinutrients and antioxidant properties of flours from colorful beans. The autoclave cooking consisted of: 6 h soaking and 5 min cooking (C5); and 20 min cooking without soaking (C20). Both cooking methods significantly promote changes on the chemical compounds studied, and the intensity of these variations were affected by the cultivars. Most of flours of C5 beans presented a lower loss of anthocyanins (3.9-70.0%), DPPH (11.7-87.2%), ABTS (0.0-82.7%), and tannins (0.0-90.0%) compared with C20. The cooked flours of Artico and Realce showed some similarities among chemical compounds, as well as the lowest concentration of tannins (0.0 mg‧g-1), antioxidant activity (0.40 µmol Trolox‧g-1), and higher amounts of oligosaccharides and acetylcholine. Most of cooked flours presented a reduction in phenolics and soyasaponins αg and βg, and an increase in soyasaponins Ba and I and oligosaccharides (mainly C20 flours).