Effect of exogenous selenium on physicochemical, structural, functional, thermal, and gel rheological properties of mung bean (Vigna radiate L.) protein

Selenium (Se) biofortification during the growth process of mung bean is an effective method to improve the Se content and quality. However, the effect of Se biofortification on the physicochemical properties of mung bean protein is unclear. The objective of this study was to clarify the changes in the composition, Se forms, particle structure, functional properties, thermal stability, and gel properties of mung bean protein at four Se application levels. The results showed that the Se content of mung bean protein increased in a dose-dependent manner, with 7.96-fold (P1) and 8.52-fold (P2) enhancement at the highest concentration. Exogenous Se application promotes the conversion of inorganic Se to organic Se. Among them, selenomethionine (SeMet) and methyl selenocysteine (MeSeCys) replaced Met and Cys through the S metabolic pathway and became the dominant organic Se forms in Se-enriched mung bean protein, accounting for more than 80 % of the total Se content. Exogenous Se at 30 g/hm2 significantly up-regulated protein content and promoted the synthesis of sulfur-containing protein components and hydrophobic amino acids in the presence of increased levels of SeMet and MeSeCys. Meanwhile, Cys and Met substitution altered the sulfhydryl groups (SH), β-sheets, and β-turns of protein. The particle size and microstructural characteristics depend on the protein itself and were not affected by exogenous Se. The Se-induced increase in the content of hydrophobic amino acids and β-sheets synergistically increases the thermal stability of the protein. Moderate Se application altered the functional properties of mung bean protein, which was mainly reflected in the significant increase in oil holding capacity (OHC) and foaming capacity (FC). In addition, the increase in SH and β-sheets induced by exogenous Se could alter the protein intermolecular network, contributing to the increase in storage modulus (G') and loss modulus (G″), which resulted in the formation of more highly elastic gels. This study further promotes the application of mung bean protein in the field of food processing and provides a theoretical basis for the extensive development of Se-enriched mung bean protein.

Common Beans as a Source of Amino Acids and Cofactors for Collagen Biosynthesis

Common beans (Phaseolus vulgaris L.) are widely consumed in diets all over the world and have a significant impact on human health. Proteins, vitamins, minerals, phytochemicals, and other micro- and macronutrients are abundant in these legumes. On the other hand, collagens, the most important constituent of extracellular matrices, account for approximately 25-30 percent of the overall total protein composition within the human body. Hence, the presence of amino acids and other dietary components, including glycine, proline, and lysine, which are constituents of the primary structure of the protein, is required for collagen formation. In this particular context, protein quality is associated with the availability of macronutrients such as the essential amino acid lysine, which can be acquired from meals containing beans. Lysine plays a critical role in the process of post-translational modifications facilitated with enzymes lysyl hydroxylase and lysyl oxidase, which are directly involved in the synthesis and maturation of collagens. Furthermore, collagen biogenesis is influenced by the cellular redox state, which includes important minerals and bioactive chemicals such as iron, copper, and certain quinone cofactors. This study provides a novel perspective on the significant macro- and micronutrients present in Phaseolus vulgaris L., as well as explores the potential application of amino acids and cofactors derived from this legume in the production of collagens and bioavailability. The utilization of macro- and micronutrients obtained from Phaseolus vulgaris L. as a protein source, minerals, and natural bioactive compounds could optimize the capacity to promote the development and durability of collagen macromolecules within the human body.

Nutritional and Functional Properties of Defatted Flour, Protein Concentrates, and Isolates of Brachytrupes membranaceus (Orthoptera: Gryllidae) (Drury: 1773) and Macrotermes subhyalinus (Isoptera: Blattodea) (Rambur: 1842) from Burkina Faso

Brachytrupes membranaceus and Macrotermes subhyalinus are edible insects in Burkina Faso. Our research aimed to evaluate the nutritional composition and functional properties of the defatted flours, protein concentrates, and isolates of Brachytrupes membranaceus and Macrotermes subhyalinus. Proximate and mineral composition were determined according to AOAC methods. The amino acid and fatty acid composition were determined by high-performance liquid chromatography (HPLC) and gas chromatography, respectively. The protein concentrates and isolates were obtained by solubilization, precipitation, and lyophilization. Macrotermes subhyalinus showed the highest protein (45.75 g/100 g), iron (11.76 mg/100 g), and zinc (13.18 mg/100 g) contents. The highest isoleucine and lysine contents, the best fat absorption (10.87 g/g), and foaming capacities (49.60%) were obtained with the isolate of Brachytrupes membranaceus. Consumption of Macrotermes subhyalinus could be used to fight or correct iron and zinc deficiencies. Macrotermes subhyalinus was a source of macronutrients and micronutrients, while the protein concentrates and isolates of Brachytrupes membranaceus were endowed with functional properties (fat absorption and foaming capacities).

A detailed comparative investigation on structural, technofunctional and bioactive characteristics of protein concentrates from different common bean genotypes

In this study, a comparative investigation on the structural, technofunctional and bioactive properties of protein concentrates from different common bean genotypes was performed. Protein extractions were carried out at different pH and salt concentrations and the highest protein content for the concentrates (77.7%) was determined for pH 11 and 0.4% of salt. The protein content of the common bean flour and their protein concentrates was in the range of 22-26.93% and 72.97-77.99%, respectively. For bioactive properties, total phenolic content ranged between 578.9 and 1355.9 and 313.5-1219.1 mg GAE/kg, for bean flours and protein concentrates, respectively. Two genotypes (G7 and G8) were the samples showing the superior biofunctional properties compared to the others. Thermal characterization showed that Td and ΔH values were in the range of 64.95-94.33 °C and 76.64-122.3 j/g, respectively. SDS-PAGE analysis revealed that the major band corresponded to the 7S vicilin. Principal component analysis showed that G2 and G6 had different characteristics in terms of technofunctional parameters while G7 and G8 were differed from the other genotypes in terms of bioactivity. The results showed that the proteins of common beans could be evaluated as good source due to high bioactivity for the enrichment of food formulations.

Physicochemical characterization of protein isolates of amaranth and common bean and a study of their compatibility with xanthan gum

Vegetables are considered to be a sustainable source of promising biomaterials such as proteins and polysaccharides. In this study, four protein isolates (amaranth protein isolate API, amaranth globulin-rich protein isolate AGR, bean protein isolate BPI, and bean phaseolin-rich protein isolate BPR) were structurally characterized under different pH conditions (2-12) and their compatibility behavior with xanthan gum (XG) in aqueous medium was described. All protein isolates showed β turn and β sheet (78.24-81.11%), as the major secondary structures without statistically significant difference under the pH conditions surveyed. Protein isolates show solubility at pH ≤ 3 (40.4-85.1%) and pH ≥ 8 (57.6-99.9%) and surface hydrophobicity results suggest protein denaturation at pH ≤ 3. In the compatibility study, API/XG ratios between 1:1 and 5:1 at pH from 7 to 9 and the BPI/XG ratios from 1:1 to 20:1 at pH 7 form gels that do not require heating nor crosslinking agent addition. Zeta potential results, on the other hand, evidenced that formation of gels is driven by attractive electrostatic interaction of the charged regions of both biopolymers and intermolecular interactions such as hydrogen bonds.

Protein, Phytate and Minerals in Grains of Commercial Cowpea Genotypes

The objective of this study was to investigate and characterize cowpea (Vigna unguiculata) genotypes for total grain protein content, storage protein fractions (globulin, albumin, prolamin, basic and acid glutelins), and phytate and minerals contents. Eighteen cowpea genotypes were selected. Total grain protein content varied from 21.4% to 29.2%, for BRS Marataoã and Paulistinha genotypes, respectively. The variation in the concentration of each protein fraction was significant (P<0.05) only for glutelins (basic and acid). The genotypes studied exhibited great similarity in the PAGE electrophoretic profile of the grain protein fractions and also in the mineral content. BRS Paraguaçu genotype exhibited higher Zn content than thegenotypes that have been previously recommended for this characteristic. The lowest phytate grain content was observed in four of the 18 genotypes studied, which also exhibited high protein contents. Although the results did not converge to the selection of a few genotypes, some specific differences were detected that which may be further explored. Considering total grain protein, mineral and phytate contents, the genotype Paulistinha revealed a better balance unveiling high grain total protein content, low grain phytate content and more homogeneous mineral composition.