Nutritional Characterization of Chilean Landraces of Common Bean

Effect of the Chilean Bean Landrace Peumo on Metabolic Syndrome-Related Parameters in C57BL/6 Mice Fed With a High-Fat Diet

SCOPE

We report a nutritional intervention involving supplementation with boiled beans and secondary metabolites-enriched extracts (SMEEs) from a Chilean Phaseolus vulgaris landrace in mice with induced metabolic syndrome (MS).

METHODS AND RESULTS

The effects of supplementation were assessed in C57BL6 mice with MS induced by a high-fat diet. Boiled beans (75 and 150 mg animal day-1) and the SMEE (0.8 and 8 mg animal day-1) were administered daily for 4 months. Weight and glycemia were measured weekly. At the end of the experiment, glycemia, total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, triglycerides, protein carbonyls, and carboxymethyl lysine (CML) levels were determined in plasma. Oral intake of the SMEE decreased glycemia at the end of the intervention. No statistically significant difference in glycemia was found for the boiled beans compared with controls. The SMEE at 0.8 mg animal day-1 decreased the total amount of CML, mainly in proteins with molecular masses >75 kDa, in agreement with the results for carbonylated proteins.

CONCLUSION

The SMEE of Peumo beans reduces glycemia at the end of the intervention and decreases total CML in plasma, suggesting a potential beneficial effect of bean intake. The results obtained in the intervention encourage further studies in Chilean bean landraces.

Bioaccessibility of carotenoids, tocochromanols, and iron from common bean (Phaseolus vulgaris L.) landraces

Common beans (Phaseolus vulgaris L.) are among the most important legumes for human nutrition. The aim of the present study was to characterize the composition and in vitro bioaccessibility of tocochromanols, carotenoids, and iron from 14 different landraces and 2 commercial common bean varieties. Phytic acid, dietary fiber, and total (poly)phenolic content were determined as factors that can modify the bioaccessibility of the studied compounds. Two carotenoids were identified, namely lutein (4.6-315 ng/g) and zeaxanthin (12.2-363 ng/g), while two tocochromanols were identified, namely γ-tocopherol (2.62-18.01 µg/g), and δ-tocopherol (0.143-1.44 µg/g). The iron content in the studied samples was in the range of 58.7-144.2 µg/g. The contents of carotenoids, tocochromanols, and iron differed significantly among the studied samples but were within the ranges reported for commercial beans. After simulated gastrointestinal digestion, the average bioaccessibility of carotenoids was 30 %, for tocochromanols 50 %, and 17 % for iron. High variability in the bioaccessible content yielded by the bean varieties was observed. Dietary fiber, phytic acid and total (poly)phenol contents were negatively correlated with the bioaccessibility of carotenoids, while iron bioaccessibility was negatively correlated with the total (poly)phenol content. The principal component analysis indicated that the bioaccessibility of lutein was the main variable involved in class separations. The composition of the food matrix plays an important role in the bioaccessibility of carotenoids, tocochromanols and iron from cooked beans.

A Past Genetic Bottleneck from Argentine Beans and a Selective Sweep Led to the Race Chile of the Common Bean (Phaseolus vulgaris L.)

The domestication process of the common bean gave rise to six different races which come from the two ancestral genetic pools, the Mesoamerican (Durango, Jalisco, and Mesoamerica races) and the Andean (New Granada, Peru, and Chile races). In this study, a collection of 281 common bean landraces from Chile was analyzed using a 12K-SNP microarray. Additionally, 401 accessions representing the rest of the five common bean races were analyzed. A total of 2543 SNPs allowed us to differentiate a genetic group of 165 accessions that corresponds to the race Chile, 90 of which were classified as pure accessions, such as the bean types 'Tórtola', 'Sapito', 'Coscorrón', and 'Frutilla'. Our genetic analysis indicates that the race Chile has a close relationship with accessions from Argentina, suggesting that nomadic ancestral peoples introduced the bean seed to Chile. Previous archaeological and genetic studies support this hypothesis. Additionally, the low genetic diversity (π = 0.053; uHe = 0.53) and the negative value of Tajima' D (D = -1.371) indicate that the race Chile suffered a bottleneck and a selective sweep after its introduction, supporting the hypothesis that a small group of Argentine bean genotypes led to the race Chile. A total of 235 genes were identified within haplotype blocks detected exclusively in the race Chile, most of them involved in signal transduction, supporting the hypothesis that intracellular signaling pathways play a fundamental role in the adaptation of organisms to changes in the environment. To date, our findings are the most complete investigation associated with the origin of the race Chile of common bean.