There is limited information on the effect of black beans (BB) as a source of protein and resistant starch on the intestinal microbiota. The purpose of the present work was to study the effect of cooked black beans with and without high fat and sugar (HF + S) in the diet on body composition, energy expenditure, gut microbiota, short-chain fatty acids, NF-κB, occluding and insulin signaling in a rat model and the area under the curve for glucose, insulin and incretins in healthy subjects. The consumption of BB reduced the percentage of body fat, the area under the curve of glucose, serum leptin, LPS, glucose and insulin concentrations and increased energy expenditure even in the presence of HF + S. These results could be mediated in part by modification of the gut microbiota, by increasing a cluster of bacteria in the Clostridia class, mainly R. bromii, C. eutactus, R. callidus, R. flavefaciens and B. pullicaecorum and by an increase in the concentration of fecal butyrate. In conclusion, the consumption of BB can be recommended to prevent insulin resistance and metabolic endotoxemia by modifying the gut microbiota. Finally, the groups fed BB showed lower abundance of hepatic FMO-3, even with a high-fat diet protecting against the production of TMAO and obesity.

En México las numerosas variedades de maíces (Zea mays L.) nativos se utilizan para elaborar además de la tortilla, una enorme cantidad de preparaciones culinarias tradicionales, lo que hace del maíz uno de los elementos fundamentales de la cocina nacional. Estos maíces siguen siendo el sustento de miles de familias rurales mexicanas. Sin embargo, ante el proceso de globalización se ha adoptado un estilo “moderno” de alimentación que tiende a sustituir a los platillos tradicionales por alimentos procesados, no necesariamente basados en maíz. Este hecho, junto con otros factores como el abandono del campo, la pérdida de memoria biocultural y el cambio climático, hacen que peligre la existencia de los maíces nativos. Conservarlos es una tarea ineludible que requiere definir estrategias a corto plazo. En este trabajo se hace explícito el papel fundamental que actualmente desempeñan los maíces nativos en la dieta mexicana, pese a los cambios registrados en los patrones de consumo alimentario. También se enlistan las preparaciones culinarias tradicionales que tienen como base el maíz, con énfasis en la relación que existe entre usos especiales, razas nativas y las características fisicoquímicas de los granos. Se destaca la necesidad de potenciar la demanda de maíces nativos a partir de la revalorización de los usos tradicionales, así como del impulso de usos novedosos y prácticas alternativas que no han sido suficientemente explotadas. Todas estas acciones son parte de las estrategias para coadyuvar en la conservación in situ de los maíces nativos mexicanos.

Corn gluten meal is a by-product of starch production that is readily available. Corn protein isolates have limited applications due to their hydrophobic nature, low solubility and limited functionality as emulsifiers. In this study, a mild acidic treatment of corn gluten meal was performed in order to achieve deamidation of asparagine and glutamine residues and modify the interfacial behavior of this byproduct. A 0.1 N HCl treatment for 6 h at 70 °C rendered a deamidation degree of 20.4%, which increased the emulsification activity index of corn gluten meal from 6.8 to 16.8 m²/g protein, with a remarkable increase in emulsion stability from 0 to 90.6% oil retention. Proteins participating in the emulsion were separated by SDS-PAGE and the main polypeptides were identified as alpha and beta-zeins. After deamidation, protein dissociation and unfolding due to the obtained negative charges resulted in enhanced functionality.

The black bean is a legume widely consumed in Latin America, however its consumption has decreased significantly in recent decades.

Alkaline-cooked corn, called nixtamal, is the basis for many traditional corn products such as tortillas, chips, and taco shells that are used widely in Mexico and Central America and in the preparation of snack foods that are consumed globally. To assess the effects of alkaline and thermal treatments on the detectability of DNA and protein for the presence of genetically modified sequences, various nixtamalized products were prepared from blends of conventional white corn containing 0.1, 1.0, and 10% transgenic corn (event CBH 351, StarLink™). Real-time quantitative polymerase chain reactions (RTQ–PCR) and immunoassays were used to determine the cry9C gene and protein, respectively, in unprocessed corn kernels, freshly prepared alkaline-cooked and ground corn (masa), masa flour, tortillas prepared from masa by heat treatment, chips prepared from damp masa dough by deep frying, and from tortillas processed at high (200°C) and low temperatures (70°C). In spite of progressive degradation of genomic DNA during processing, RTQ–PCR genetic analysis allowed detection and quantification of the cry9C gene in all products prepared from 10, 1, and 0.1% StarLink corn, except deep-fried chips containing 0.1% StarLink. Enzyme-linked immunosorbent assays readily detected <1ppm cry9C protein in all blends of unprocessed corn (10, 1, and 0.1% StarLink) as well as in nonfried tortilla and masa products. This technique was not suitable for thermally treated nixtamalized products containing <1% transgenic corn.