Isolation of individual isoflavone species from soybean by solvent extraction followed by the combination of macroporous resin and aluminium oxide separation

Advances in synthesizing plant-derived isoflavones and their precursors with multiple pharmacological activities using engineered yeasts

Isoflavones such as daidzein and genistein are naturally occurring compounds found in plants such as legumes. They have diverse pharmacological activities, making them valuable in the food, pharmaceutical, and cosmetic industries. Currently, isoflavones are mainly obtained through the extraction of plant biomass. Chemical synthesis is challenging for most isoflavones due to the complexity of their structures. The limited supply of isoflavones cannot meet the market demands. Advances in synthetic biology have provided a sustainable and efficient solution for the production of isoflavones, with yeasts often serving as the microbial chassis for biosynthesis. This review summarizes the pharmacological properties of specific isoflavones, their biosynthetic pathways, and the technical strategies used in engineered yeasts for isoflavone production. In addition, the development of synthetic biology and state-of-the-art biotechnological strategies for the environmentally friendly production of bioactive isoflavones is discussed.

Sustainable extraction of phytoestrogens from soybean and okara using green solvents

Soy extract waste, okara, is a rich source of bioactive compounds such as isoflavones, which are phytoestrogens with potential health benefits. To develop a green approach to recovering these compounds and valorizing okara, a study was developed to screen variables for the extraction of isoflavones from okara and soybean (for comparison) using Deep Eutectic Solvents (DES) composed with choline chloride ([Ch]Cl) and acetic acid (AA) ([Ch]Cl: AA, 1:2). A fractional design (24-1) was used to evaluate variables in the extraction of isoflavones, followed by a Central Composite Rotatable Design (CCRD). The variables analyzed included temperature, % water, solid-liquid ratio, and stirring speed. Furthermore, cytotoxicity tests were carried out using Caco-2 cells from the extracts obtained under best conditions, and the solid matrices were evaluated by scanning electron microscopy (SEM). This study showed that 1194.56 µg TIC/g of dried soybeans were extracted using [Ch]Cl: AA with 70 % water added at low temperature (25 °C), 500 rpm, S/L ratio of 10 mg/mL and extraction time of 2 h. For okara, 450.9 µg TIC/g of dry okara were extracted at 40 °C, 500 rpm, 61.5 % water in DES, S/L ratio of 10 mg/mL, and extraction time of 1 h. In the cytotoxicity tests, it was observed that the neutralization step of the extracts is necessary to reduce the cytotoxic effects caused by the high acidity of the solvents. In summary, this work has shown that aqueous mixtures of DES can be used as sustainable alternative techniques for recovering isoflavones from soybean residue and can replace toxic conventional solvents.

Impact of chickpea biofortification on the bioaccessibility of micronutrients and their relationship to obesity-linked biological activities

Micronutrient deficiencies are a critical factor in the development of obesity. This work aimed to determine the Se and Zn bioaccessibility on biofortified chickpea flour and evaluate their impact on the antioxidant and anti-inflammatory activities. The greatest increase (235 %) in isoflavones was observed in the ZnSO4-treatment compared to the control. Malonylated-formononetin-glucoside was the major isoflavone (43 %-50 %) found in the treatments. Na2SeO3-treated seeds showed the highest Se accumulation, while the greatest Zn accumulation was found in ZnSO4-treated seeds. Se bioaccesibility followed the order: Germinated Control>ZnSO4 > ZnSeO3 > ZnSO₄ + Na2SeO3 > Na2SeO3, while in the seeds biofortified with Zn salts showed the order: Germinated Control>ZnSeO3 > ZnSO₄ + Na2SeO3 > Na2SeO3 > ZnSO4. All treatments showed antioxidant activity. Na2SeO3-treatment (15.625 μg/mL) showed a significant reduction of 52 % in NO production compared to the Germinated Control. These findings demonstrated the biological value of food biofortification in providing minerals in the diet to combat the oxidative stress characteristic of obesity.

Methods of Analysis of Phytoestrogenic Compounds: An Up-to-Date of the Present State

Phytoestrogens, natural compounds with structural similarity to 17-β-estradiol, are known to have potential health benefits, including in hormone-dependent malignancies. The therapeutic interest and some safety concerns observed triggered the need to develop accurate methods to assess their level in different matrices. This narrative review examines the existing analytical methods used to isolate, quantify, and characterize phytoestrogens and their metabolites in plants, foods, and biological samples. Different conventional and modern extraction techniques, such as ultrasonication-assisted extraction, supercritical fluid extraction, or enzyme-assisted extraction, were presented and compared. The advantages and limitations of the existing analytical methods, such as high-performance liquid chromatography using different sensitive detectors, gas chromatography often coupled with mass spectrometry, and immunoassay methods, are highlighted, along with the need for ongoing research to improve the sensitivity and selectivity of the analysis.

Deep eutectic solvents as an alternative for extraction of flavonoids from soybean (Glycine max (L) Merrill) and okara: An experimental and computational approach based on COSMO-SAC model

In this study, different Deep Eutectic Solvents based on choline chloride ([Ch]Cl) with carboxylic acids, sugars, and glycerol, were investigated as alternative solvents for the extraction of flavonoids from soybean and okara. Initially, the COSMO-SAC was investigated as a tool in solvent screening for the extraction of flavonoids. Experimental validation was performed using total flavonoid analysis with the solvents that showed greater interaction with the solutes. The extracts obtained from soybean and okara using the DES [Ch]Cl:acetic acid added with 30 % water showed the highest total flavonoid content, 1.05 mg eq. of catechin/g dry soybean and 0.94 mg eq. of catechin /g dry okara, respectively. For phenolic compound extraction, [Ch]Cl: acetic acid DES extracted approximately 1.16 mg GAE/g of soybean and 0.69 mg GAE/g of okara. For antioxidant activity, soybean and okara extracts obtained with [Ch]Cl: acetic acid showed FRAP results of 0.40 mg Trolox/mL of extract and 0.45 mg Trolox/mL of extract, respectively. In addition, the isoflavones daidzein, genistein, glycitein, daidzin, genistin, and glycitin were identified and quantified in the soybean and okara extracts obtained with DES [Ch]Cl: acetic acid with 30% water, totaling 1068.05 and 424.32 µg total isoflavones/g dry sample. Therefore, The COSMO-SAC model was a useful tool in solvent screening, saving time and costs. Also, DES can be an alternative solvent for extracting flavonoids to replace conventional organic solvents, respecting current environmental and human health concerns.

Separation of soy isoflavones from soy sauce residue by MIL-100(Fe)

Soy sauce residue (SSR) is a valuable biological resource, which contains soy isoflavones (SIs) with antioxidant activity and can be used to scavenge radicals. Herein, MIL-100(Fe) was synthesized for the extraction of SIs from SSR. Under the optimal adsorption conditions, the adsorption capacity of MIL-100(Fe) for SIs was 51.81 mg/g, which could achieve a purity of 56.17% and a recovery of 93.8%. These results demonstrated MIL-100(Fe) possessed effective properties of adsorption and purification for SIs. The content of SIs in the purified product was 167 times than that of SSR. The purified total SIs had a good antioxidant activity. The established method had a good scavenging ability toward 2, 2-diphenyl-1-picrylhydrazyl, superoxide and hydroxyl radicals, with IC₅₀ values of 0.177, 0.116 and 0.082 mg/mL, respectively. Besides, the ferrous ion chelating potency was better than others, with IC₅₀ values of 0.63 ± 0.0044 mg/mL. The established method was suitable for large-scale separation of purified total SIs and provided a reference for purification of bioactive factors from complex substrates.

Nutritional quality of different potassium efficiency types of vegetable soybean as affected by potassium nutrition

Pot experiments were conducted in 2017, 2019, and 2020 to examine the effects of potassium nutrition on the nutritional components of vegetable soybeans with different K efficiency at immature and mature stages. Two vegetable soybean varieties with higher K efficiency and two varieties with lower K efficiency were studied in the low available K soil under the condition of no K and normal K fertilization. The results indicated that almost all nutritional components in vegetable soybean were affected by K, genotypes, inter-annual differences, and their interactions. In general, no K fertilization increased protein and amino acid concentrations but decreased oil, soluble sugar, sucrose, K, Mg, and Fe concentrations in immature and mature vegetable soybean. The sensitivity of nutritional components to K nutrition differed among varieties. For instance, K high-efficiency varieties generally exhibited higher protein and amino acid concentrations without K application. K high-efficiency vegetable soybeans are low-K tolerance varieties to isoflavones. The results of this study provide insights for high yield and quality vegetable soybean breeding against soil K deficiency.