Phaseolus vulgaris L. is the most commonly consumed legume in the world, given its high vegetable protein content, phenolic compounds, and antioxidant properties. It also represents one of the most sustainable, low-carbon and sources of food available at present to man. This study aims to identify the nutrients, antinutrients, phenolic composition, and antioxidant profile of 10 common bean cultivars (Arikara yellow, butter, cranberry, red kidney, navy, pinto, black, brown eyed, pink eyed, and tarrestre) from two harvest years, thereby assessing the potential of each cultivar for specific applications in the food industry. Navy and pink eyed beans showed higher potential for enrichment of foodstuffs and gluten-free products due to their higher protein and amino acid contents. Additionally, red kidney, cranberry and Arikara yellow beans had the highest content of phenolic compounds and antioxidant properties, which can act as functional ingredients in food products, thus bringing health benefits. Our study highlights the potential of using specific bean cultivars in the development of nutrient-enriched food and as functional ingredients in diets designed for disease prevention and treatment.

The present study aimed to investigate the effects of different cooking conditions-atmospheric (100°C) and pressure cooking (115°C)-on the phenolic composition and antioxidant activity of methanolic extracts of four Phaseolus vulgaris varieties and soy (Glycine max). Contrary to soy, in P. vulgaris varieties both cooking methods increased drastically the total phenolic, flavonoid, and ortho-diphenol content, as well as antioxidant capacity. These results were corroborated by HPLC analysis, where an overall increase of phenolic acids and flavonoids was detected in processed samples. However, draining the cooking water significantly decreased phenolic acids, flavonoids and antioxidant activity in all P. vulgaris varieties and as well as soy. The hypothesis that cooking increases the compound accessibility and nutritional value through increased release of phytochemicals was verified in the present study for P. vulgaris varieties. Keeping the cooking water is crucial to the increased nutritional value of all Phaseolus varieties. Overall, compared with the tested varieties of Phaseolus, soy, to which many health benefits are attributed, is not the best legume source of antioxidants.

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Catechol-O-methyltransferase (COMT, EC 2.1.1.6) is an enzyme that catalyzes the methylation of catechol substrates, and while structural and functional studies of its membrane-bound isoform (MBCOMT) are still hampered by low recombinant production, Pichia pastoris has been described as an attractive host for the production of correctly folded and inserted membrane proteins. Hence, in this work, MBCOMT biosynthesis was developed using P. pastoris X33 and KM71H cells in shake flasks containing a semidefined medium with different methanol concentrations. Moreover, after P. pastoris glass beads lysis, biologically and immunologically active hMBCOMT was found mainly in the solubilized membrane fraction whose kinetic parameters were identical to its correspondent native enzyme. In addition, mixed feeds of methanol and glycerol or sorbitol were also employed, and its levels quantified using liquid chromatography coupled to refractive index detection. Overall, for the first time, two P. pastoris strains with opposite phenotypes were applied for MBCOMT biosynthesis under the control of the strongly methanol-inducible alcohol oxidase (AOX) promoter. Moreover, this eukaryotic system seems to be a promising approach to deliver MBCOMT in high quantities from fermentor cultures with a lower cost-benefit due to the cheaper cultivation media coupled with the higher titers tipically achieved in biorreactors, when compared with previously reported mammallian cell cultures.

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