Saline as solvent and ethanol-based purification process for the extraction of proteins and isoflavones from wet okara.

Okara, the solid byproduct of water-soluble soybean extract production, is a potential source of proteins and isoflavones. This study investigated different experimental configurations for extracting these compounds from wet okara, including lipid removal with ethanol at different stages of the recovery process, sequential crosscurrent extraction, and using a saline MgCl2 solution as the solvent. Three washes with a 60:40 ethanol:water (w/w) solution after isoelectric precipitation significantly increased protein content by reducing lipid content (60 %). The crosscurrent approach using 0.05 M MgCl2 yielded okara proteinaceous material with 248 µg/g daidzein and 236 µg/g genistein, along with a 3 % increase in protein content, attributed to enhanced extraction of 7S globulins. These configurations notably affected the functional properties of the protein materials. Overall, this research provides detailed insights into the composition and properties of proteins extracted from wet okara, facilitating their specialized application in food products.

Phytosterols and γ-Oryzanol as Cholesterol Solid Phase Modifiers during Digestion.

Literature reports that ingestion of phytosterols and γ-oryzanol contributes to cholesterol lowering. Despite in vivo observations, thermodynamic phase equilibria could explain phenomena occurring during digestion leading to such effects. To advance the observations made by previous literature, this study was aimed at describing the complete solid-liquid phase equilibrium diagrams of cholesterol + phytosterol and γ-oryzanol systems by DSC, evaluating them by powder X-ray, microscopy, and thermodynamic modeling. Additionally, this study evaluated the phenomena observed by an in vitro digestibility method. Results confirmed the formation of solid solution in the cholesterol + phytosterols system at any concentration and that cholesterol + γ-oryzanol mixtures formed stable liquid crystalline phases with a significant melting temperature depression. The in vitro protocol supported the idea that the same phenomena can occur during digestion in which mechanochemical forces were probably the mechanisms promoting cholesterol solid phase changes in the presence of such phytocompounds. In this case, these changes could alter cholesterol solubility and possibly its absorption in the gastrointestinal lumen.

Valorization of the baru (Dipteryx alata Vog.) processing chain: Technological properties of defatted nut flour and oil solubility in ethanol and isopropanol.

Baru, a Brazilian Cerrado native fruit, stands out for its high nutritional value. Considering that reports about its technological potential are scant, this study aimed to add value to the processing chain. For that, ethanol and isopropanol were evaluated in terms of their suitability to solubilize baru nut oil (BNO), extract baru nut cake oil (BNCO), and obtain a protein-rich defatted flour. The BNO solubility in alcohols was adequately described by nonrandom two-liquid (NRTL) parameters, and the highest solubilization capacity was achieved with absolute isopropanol. Alcoholic extraction did not affect the BNCO tocopherol content (80-112 mg/kg oil) or its fatty acid composition. Both protein solubility and thermal stability were negatively affected by solvent hydration, temperature, and contact stages. However, the materials exhibited adequate water and oil absorption capacities (3.5 and 1 g/g sample), as well as improved foaming capacity and stability, confirming their potential for use in several food formulations.

Profile and content of isoflavones on flaked and extruded soybeans and okara submitted to different drying methods.

Isoflavones (IFs) are biocompounds found in considerable amounts in soybean grains. However, to originate soybean-based materials, the grains must be subjected to numerous thermal and mechanical treatments, which can impair the IFs content. The influence of these treatments was investigated and a protocol for IFs extraction and quantification is proposed. Sequential extractions were performed on industrially pretreated soybean samples (broken, flakes, and collets), on okara submitted to different drying methods (freeze-drying, forced convection, and under vacuum), and on soybean oils extracted with hexane and ethanol. ß-glucosides levels were decreased by the thermal processes of lamination, expansion, and drying, while the aglycone forms were not affected. Lyophilization was identified as the most viable drying method for the quantification of IFs in okara. Soybean oils extracted with ethanol presented significant amounts of aglycone. Furthermore, two stages of extraction were sufficient for the recovery of the IFs from different matrices.

Pressurized liquid extraction of flavanols and alkaloids from cocoa bean shell using ethanol as solvent.

Cocoa shell (CS) is a co-product of the cocoa industry used mainly as fuel for boilers but with secondary applications as fertilizer and in animal feed. Although it is known that this material is rich in flavanols and alkaloids, to date, a study has not been conducted that has quantitatively identified these compounds in CS. Thus, the aim of this work was to characterize CS in terms of its composition, regarding catechin, epicatechin, procyanidin B2, caffeine and theobromine, and to evaluate the extraction kinetics of the total flavanols using pressurized liquid extraction (PLE) with absolute ethanol. For the determination of the extraction kinetic data, the DMAC method was used, while each compound was quantified using a UPLC-MS/MS analysis. The major compounds found were theobromine and epicatechin (mean values of 9.89 and 3.5 mg/g CS, respectively). PLE proved to be quite effective; the flavanols extraction yield was enhanced by increasing the temperature and extraction time however, high extraction times and temperatures degraded the procyanidins B2. Peleg's model applied to extraction data description provided a reasonable agreement with the experimental results, which allows their application in modeling and optimization of solid-liquid extraction of the total flavanols from cocoa bean shell.