NMR and LC-MS assessment of compound variability of common bean (Phaseolus vulgaris) stored under controlled atmosphere

Lutein–stachyose (LS) amphiphilic oligosaccharide derivatives improve the oral bioavailability of lutein

A new amphiphilic oligosaccharide derivative, based on lutein modification onto the OH position of stachyose with facile and mild esterification, was prepared and used to improve the oral bioavailability of lutein. The structures of lutein-stachyose derivative (LS) were confirmed by Fourier transform infrared spectroscopy and hydrogen-1 nuclear magnetic resonance, indicating that one stachyose is connected to one lutein through succinic acid. The critical micelle concentration of LS was approximately 6.86 ± 0.24 mg/mL, corresponding to the free lutein concentration of approximately 2.96 mg/mL. LS has better digestive stability and free radical scavenging ability, and it could inhibit the degradation of lutein in the gastrointestinal tract. Importantly, LS is nontoxic to cells and zebrafish embryos. In terms of oral bioavailability in rats, the AUC_0-12h values of LS were 2.26 times higher than those of free lutein. Therefore, stachyose modification is a promising strategy for improving the oral bioavailability of fat-soluble lutein.

Bean cultivars (Phaseolus vulgaris L.) under the spotlight of NMR metabolomics

The seeds of Phaseolus vulgaris are a rich source of protein consumed around the world and are considered as the most important source of proteins and antioxidants in the Mexican diet. This work reports on the 1H NMR metabolomics profiling of the cultivars Peruano (FPe), Pinto (FPi), Flor de mayo (FM), Negro (FN) and Flor de junio (FJ). Total phenolics, total flavonoids and total protein contents were determined to complement the nutritional facts in seeds and leaves. According to our results, the metabolomics fingerprint of beans seeds and leaves were very similar, showing the presence of 52 metabolites, 46 in seeds and 48 in leaves, including 8 sugars, 17 amino acids, 15 organic acids, 5 nucleosides and 7 miscellaneous compounds. In seeds, free amino acids were detected in higher concentrations than in the leaves, whereas organic acids were more abundant in leaves than in seeds. With multivariate and cluster analysis it was possible to rank the cultivars according to their nutritional properties according to NMR profiling, then a machine learning algorithm was used to reveal the most important differential metabolites which are the key for correct classification. The results coincide in highlighting the FN seeds and FPe leaves for the best nutritional facts. Finally, in terms of cultivars, FN and FM present the best nutritional properties, with high protein and flavonoids content, as well as, a high concentration of amino acids and nucleosides.

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

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).