Correction: Black bean protein concentrate ameliorates hepatic steatosis by decreasing lipogenesis and increasing fatty acid oxidation in rats fed a high fat-sucrose diet.

Correction for 'Black bean protein concentrate ameliorates hepatic steatosis by decreasing lipogenesis and increasing fatty acid oxidation in rats fed a high fat-sucrose diet' by Irma Hernandez-Velazquez et al., Food Funct., 2020, DOI: .

Black bean protein concentrate ameliorates hepatic steatosis by decreasing lipogenesis and increasing fatty acid oxidation in rats fed a high fat-sucrose diet.

The black bean is a legume widely consumed in Latin America, however its consumption has decreased significantly in recent decades. There is evidence that its consumption generates beneficial health effects due in part to the type of protein, resistant starches and polyphenols. Thus, their use in food formulation could impact health status. Therefore, the purpose of the present work was to evaluate the effects of the consumption of a bean protein concentrate (BPC) and a whole cooked bean flour (WCB) on body composition, glucose metabolism and energy expenditure in Wistar rats fed a control diet or high-fat diets with 5% sucrose in the drinking water. With this aim, rats were fed the experimental diets for 10 weeks. The results showed that consumption of either BPC or WCB reduced weight gain and body fat despite the consumption of a high-fat diet. This change was associated with a significant increase in energy expenditure and the capacity to adapt fuel oxidation to fuel availability. As a result, rats fed a bean-based diet had lower circulating glucose and insulin concentrations and normal glucose tolerance, which was associated with decreased expression of lipogenic genes in the liver. These results suggest that the type of protein and bioactive compounds particularly phenolic and flavonoid compounds present in BPC are suitable to improve the formulations used in dietary strategies for subjects with obesity or type 2 diabetes. The addition of legumes to the diet of subjects with insulin resistance, including black beans, could improve their metabolic status.

Reply: "Comment on "Consumption of Cooked Black Beans Stimulates a Cluster of Some Clostridia Class Bacteria Decreasing Inflammatory Response and Improving Insulin Sensitivity." Nutrients 2020, 12(4), 1182".

We appreciate the interest of Dr [...].

Consumption of Cooked Black Beans Stimulates a Cluster of Some Clostridia Class Bacteria Decreasing Inflammatory Response and Improving Insulin Sensitivity.

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.

The mTORC1-Signaling Pathway and Hepatic Polyribosome Profile Are Enhanced after the Recovery of a Protein Restricted Diet by a Combination of Soy or Black Bean with Corn Protein.

Between 6% and 11% of the world's population suffers from malnutrition or undernutrition associated with poverty, aging or long-term hospitalization. The present work examined the effect of different types of proteins on the mechanistic target of rapamycin (mTORC1)-signaling pathway in: (1) healthy; and (2) protein restricted rats. (1) In total, 200 rats were divided into eight groups and fed one of the following diets: 20% casein (C), soy (S), black bean (B), B + Corn (BCr), Pea (P), spirulina (Sp), sesame (Se) or Corn (Cr). Rats fed C or BCr had the highest body weight gain; rats fed BCr had the highest pS6K1/S6K1 ratio; rats fed B, BCr or P had the highest eIF4G expression; (2) In total, 84 rats were fed 0.5% C for 21 day and protein rehabilitated with different proteins. The S, soy + Corn (SCr) and BCr groups had the highest body weight gain. Rats fed SCr and BCr had the highest eIF4G expression and liver polysome formation. These findings suggest that the quality of the dietary proteins modulate the mTORC1-signaling pathway. In conclusion, the combination of BCr or SCr are the best proteins for dietary protein rehabilitation due to the significant increase in body weight, activation of the mTORC1-signaling pathway in liver and muscle, and liver polysome formation.

Survey of aflatoxins in maize tortillas from Mexico City.

In Mexico, maize tortillas are consumed on a daily basis, leading to possible aflatoxin exposure. In a survey of 396 2-kg samples, taken over four sampling days in 2006 and 2007 from tortilla shops and supermarkets in Mexico City, aflatoxin levels were quantified by HPLC. In Mexico, the regulatory limit is 12 µg kg⁻¹ total aflatoxins for maize tortillas. In this survey, 17% of tortillas contained aflatoxins at levels of 3-385 µg kg⁻¹ or values below the limit of quantification (12 µg kg⁻¹ and 87% were below the regulatory limit. Average aflatoxin concentrations in 56 contaminated samples were: AFB1 (12.1 µg kg⁻¹); AFB2 (2.7 µg kg⁻¹); AFG1 (64.1 µg kg⁻¹) and AFG2 (3.7 µg kg⁻¹), and total AF (20.3 µg kg⁻¹).

Real-time and conventional PCR detection of Liberty Link rice varieties and transgenic soy in rice sampled in the Mexican and American retail markets.

Samples of rice from Mexican and USA retail stores were analyzed for the presence of transgenic (GM) events using real-time PCR. In screening for the CaMV35S promoter sequence (35SP), positive results were found in 49 and 35% of the Mexican and American samples, respectively. In further investigations in Mexican samples, 43% were positive for P35S::bar, with two above the quantifiable limit; these were 0.07% and 0.05% GMO. Fourteen out of the sixteen positive samples were labeled as imported from the USA. In testing samples bought in American retail shops, 24% showed positive results, all below the quantifiable range. It could be deduced that P35S::bar positive samples were Liberty Link(R) (LL) rice. In distinguishing between LL601 and LL62, end-point PCR was used, corroborating the P35S::bar amplicon length difference of these events. LL62 was found in one rice sample purchased in Mexico and two in the USA samples. Its presence was verified with the 35S terminator sequence. All other LL positive samples contained LL601. None of the samples analyzed showed the presence of Bt63 rice. The LL rice varieties found have been identified as not being commercially cultivated, and so their presence requires further investigation. 35SP was also present in samples which did not have any LL rice. Maize sequences could not be detected in any of the samples; however, soybean DNA was found in Mexican and USA rice samples. The Roundup Ready(R) trait was detected in trace amounts in 16 and 6% of the rice samples bought in Mexico and the USA, respectively. Real-time PCR was shown to be the method of choice for the sensitive and rapid screening of commodities and retail samples for the detection of GM and other contamination.

Characterization of a 19 kDa alpha-zein of high purity.

A highly pure alpha-zein was extracted from corn flour using ethanol (95%). Subsequently, ion-exchange chromatography was performed, using SP-Sepharose that yielded a highly homogeneous protein. This protein migrated as a single band in 20% SDS-PAGE and in pH gradient gels, showing an isoelectric point of 6.8. Mass spectrometry (MALDI-TOF-MS) showed a single peak with a molecular mass of 24 535 Da. It was identified as Z19, when comparing the sequence obtained in an automatic Edman sequencer with the Swissprot database using BLAST. The molar extinction coefficient, determined by dry weight in 70% methanol, was 12 415.49 M(-1) cm(-1) at 280 nm. Light scattering showed its presence in a monodispersed state of 44-66 kDa aggregates in methanol (70%). Circular dichroism spectra allowed the estimation of an alpha-helix content that was lower than the one found for a mixture of two alpha-zeins but with a higher content of beta sheets.

Suitability of real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay for cry9C detection in Mexican corn tortillas: fate of DNA and protein after alkaline cooking.

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 degrees C) and low temperatures (70 degrees 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 <1 ppm 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.

Chemical composition of a mixture of single-cell protein obtained from Kluyveromyces fragilis and whey proteins

De la fermentación de suero de leche entera se obtuvo un producto consistente en una mezcla de biomasa de Kluyveromyces fragilis y proteínas coaguladas del suero. El producto tuvo una composición similar a la de productos lavados de que se informa en la literatura, con un alto contenido de proteína cruda y un bajo contenido de cenizas. Asimismo, acusó tambiém un alto contenido de aminoácidos azufrados y de triptofano, los que usualmente son limitantes en al biomasa de levadura. El contenido de lisina fue inexplicablemente más bajo de lo esperado resusltando ser el aminoácido limitante. La calificación química de la protéina fue 91%. Del producto de biomasa com proteínas de suero se obtuvo un concentrado proteínico con un rendimento de 80%. El contenido de proteína del aislado fue de 75% y el contenido de ácidos nucleícos se redujó en 90.8%. Los restos de pared celular también se redujeron considerablemente

Development of an enzymatic fish hydrolysate and its use in instant soup bases

El desarrollo satisfactorio de productos a base de pescado, a bajo costo, constituye un tema de especial interés en los países en vías de desarrollo. Consciente de ello, nuestro grupo ha venido estudiando varios métodos de conservación de pescado, tales como autólisis con altas concentraciones de sal, y ha logrado obtener una salsa de alto valor nutritivo y larga vida de anaquel. No obstante, el proceso de reacción toma de cuatro a seis meses. En el estudio de que aquí se informa, se logró acelerar y controlar la hidrólisis mediante el uso de las enzimas siguientes: papaína, HT proteolítica, y Brew (N) zima. El hidrolizado se mezcló entonces con cereales para preparar sopas instantáneas. Como lo indican los resultados, el mejor hidrolizado se obtuvo con Brew (N) zima a 50-C y un término de 8.30 horas. El hidrolizado contiene 93.0g/100g de proteína cruda, un índice de eficiencia proteínica (PER) y una utilización proteínica neta (NPU) de 60% de la NPU de caseína, así como un contenido de 0.8% de extracto etéreo. Las mezclas de menor costo y mayor valor nutritivo fueron: hidrolizado-trigo-harina de soya, e hidrolizado-arroz-harina de soja, con 38.3 y 29.7 g de proteína por 100 g de mezcla, respectivamente, y una NPU de 79.0 y 79.8% en relación con la caseína, respectivamente. Las sopas preparadas tuvieron una tasa de aceptación satisfactoria. No se constataron diferencias significativas en cuanto a sabor ni aroma a un nivel de 95% de confiabilidad. El costo por gramo de proteína es de US$0.22 por kg, aproximadamente