Protein extraction from defatted wheat germ by reverse micelles: Optimization of the forward extraction

Self-Organization of Carbohydrate-Derived Amphiphilic Compounds: Insights into Their Supramolecular Assembly

This study describes the synthesis and self-assembly properties of two sugar-derived surfactants constructed by click reaction from readily accessible building blocks. After structural characterization, their self-assembly processes were studied in two biocompatible solvents, isopropyl myristate and methyl laurate, as well as in toluene. Detailed experiments by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS) confirmed the formation of reverse micelles (RMs). The findings reveal the formation of spherical aggregates with low polydispersity indices, indicating a high degree of size uniformity. SAXS analysis further demonstrated that these aggregates possess a smooth and well-defined RMs-nonpolar solvent interface. Notably, the system in toluene as the non-polar phase exhibited a unique behavior, suggesting distinct structural characteristics that differ from those observed in the biocompatible solvents. A low-resolution structural model revealed that the aggregates contain an internal gap compatible with a reverse vesicle consisting of a bilayer of amphiphile with the hydrophilic heads pointing towards the interior and the exterior of the bilayer with toluene on both sides of the bilayer. In summary, this study explores the self-assembly characteristics of sugar-based surfactants in non-polar environments that mimic biological membranes. The findings highlight the significant potential of these surfactants in supramolecular chemistry and glycobiology.

Aqueous phase extractable protein of wheat bran and germ for the production of liquid and semi-solid foods

To achieve a more sustainable global food production, a shift from animal to plant protein based food is necessary. At the same time, these plant proteins are preferentially derived from side-streams of industrial processes. Wheat bran and germ represent two major side-streams of the wheat milling industry, and contain aqueous-phase soluble proteins with a well-balanced amino acid composition. To successfully use wheat bran and germ proteins in novel plant-based liquid and semi-solid foods, they need to (i) be rendered extractable and (ii) contribute functionally to stabilizing the food system. Prior heat treatment and the occurrence of intact cell walls are important barriers in this regard. Several strategies have been applied to overcome these issues, including physical processing and (bio)chemical modification. We here present a comprehensive, critical overview of the aqueous-phase extraction of protein from (modified) wheat bran and germ. Moreover, we discuss the functionality of the extracted protein, specifically in the context of liquid (foam- and emulsion-type) and semi-solid (gel-type) food applications. In each section, we identify important knowledge gaps and highlight several future prospects that could further increase the application potential of wheat bran and germ proteins in the food industry.

Process optimisation of defatted wheat germ protein extraction in a novel alkaline-based deep eutectic solvent (DES) via Box-Behnken experimental design (BBD)

This is the first study to provide a preliminary investigation into the recovery of protein from wheat germ and the prediction of their extraction conditions in microwave cavity using a novel DES solvent. The response surface methodology was used to predict the microwaved protein extraction conditions of the DWG. The effects of DES buffer-concentration (X₁: 0.01-1.00 g/mL), microwave power (X₂: 50-250 W), irradiation time (X₃: 1-5 min) and sample-to-buffer ratio (X₄: 1:10-1:50) were tested using a single factor and Box-Behnken experimental design. Under the optimized conditions (X₁ = 0.52 g/mL, X₂ = 186 W, X₃ = 3.28 min, and X₄ = 1:39) protein yield and absorbed microwave were obtained at the optimal value of 33.00 % and 677 J/min, respectively with no denaturation of the protein as validated from the SDS-PAGE gel electrophoresis profile. Consequently, this investigation provides a practical approach for the extraction of bioactive protein from DWG using a novel deep eutectic solvent.

Application of enzymes in the preparation of wheat germ polypeptides and their biological activities

Wheat germ, a byproduct of wheat industrial processing, contains 30% protein and is a comprehensive source of plant-based protein. But a large amount of wheat germs are disposed of as waste every year. Wheat germ protein can be hydrolyzed into polypeptides with antioxidant, antihypertensive, anti-tumor, bacteriostatic and other activities. At present, researches on the hydrolysis of wheat germ protein and the preparation of bioactive peptides from wheat germ protein have attracted increasing attentions. However, the traditional protein hydrolysis method, protease hydrolysis, can no longer meet the market's needs for efficient production. Various auxiliary means, such as ultrasound, microwave and membrane separation, were applied to boost the yield and biological activity of wheat germ peptides by enzymatic hydrolysis. Under ultrasound and microwave, the protein structure may expand to increase the binding sites between enzyme and substrate and promote hydrolysis efficiency. Membrane separation is applied to separate products from enzymatic hydrolysate to reduce the inhibitory effect of the product on the hydrolysis reaction. The paper reviewed the hydrolysis methods of wheat germ protein and summarized the biological activity of wheat germ peptides to provide references for further study of wheat germ peptides.

Isolation, process optimisation and characterisation of the protein from the de-oiled cake flour of Madhuca latifolia

This work reports the isolation of the protein from the flour of an underutilised agro waste, a de-oiled cake of Madhuca latifolia using the bis (2-ethylehexyl) sodium sulfosuccinate salt reverse micelle and the characterisation of the protein through various techniques. The experimental conditions for the extraction were optimised using Box-Behnken design. The highest yield of the protein was achieved when the extraction parameters, i.e. KCl concentration, KCl amount, and pH of the medium, were 0.5 M, 1.25 ml, and 9.02, respectively. The experimental yield (75.56%) obtained under the optimised conditions matched extremely well with the predicted yield (75.19%). The analysis of the biochemical composition envisaged the occurrence of 2S albumin, 7S globulin, and 11S globulin as the major components in the protein. The X-ray diffraction pattern supported the β-sheets structure of the protein. The imaging of the protein through a scanning electron microscope revealed the shape and surface of the protein to be spherical and smooth, respectively. Thus, the protein isolate of the de-oiled cake flour of Madhuca latifolia could be utilised towards food product development and relevant fields.

Microemulsions as nano-reactors for the solubilization, separation, purification and encapsulation of bioactive compounds

Bioactive components possess various functionalities and are most interested for different food, nutraceutical and pharmaceutical formulations. The current review will discuss the preparation methods and fabrication techniques to design microemulsions (MEs) for the solubilization, separation, encapsulation and purification of various agro-food bioactive compounds. ME systems have shown suitable potential in enhancing oil recovery, protein extraction, and isolation of bioactive compounds. Moreover, the capability of ME based systems as drug and nutraceutical delivery cargos, and synthesis of various organic and inorganic nanoparticles, especially using biopolymers, will be investigated. ME liquid membranes are also developed as nano-extractor/nano-reactor vehicles, capable of simultaneous extraction, encapsulation or even synthesis of hydrophilic and lipophilic bioactive compounds for food, nutraceutical and drug applications.