Modifying quinoa protein for enhanced functional properties and digestibility: A review

Structural and functional modifications of quinoa protein via hyaluronic acid-induced Maillard reaction

In recent years, quinoa protein (QP) has attracted attention for its balanced amino acids composition, but its limited techno-functional properties continue to pose challenges for its utilization. Non-enzymatic Maillard glycation is considered as a promising strategy to expand the utilization of plant proteins in food processing due to its cost-effectiveness, spontaneous nature, and the lack of need for additives to initiate the reaction. Furthermore, the use of hyaluronic acid (HA) as an ingredient in food products is becoming increasingly accepted and popular. Therefore, the present study aims to prepare QP-HA glyconjugates by wet heating and to investigate the effects of sugar/protein ratios and reaction times on the structural features and functional properties of QP. The results showed that heating time and sugar/protein concentration ratio obviously affected the degree of grafting, structure and hydrophobicity of the conjugates. The random coil content of QP-HA increased significantly, resulting in a more flexible structure after Maillard glycation. After 3 h of glycation reaction, the QP-HA conjugates showed better emulsification, solubility, thermal stability and antioxidant activity compared to QP. Accordingly, these results indicate that polysaccharide-induced Maillard reaction is a potentially attractive approach for selective functionality enhancement and nutraceutical development of QP, which provides a new way to expand the application range of QP.

Enhancing the texture and modulating digestive behavior of gluten-free quinoa sponge cakes via microwave-assisted alkaline amino acid treatment

This study investigated the effects of microwave treatment combined with lysine and arginine on gluten-free quinoa sponge cakes. The results indicated that the addition of these amino acids during microwave treatment significantly increased the cakes' specific volume by 49 %. X-ray diffraction analysis revealed that cake crystallinity reached 56.23 % and 49.17 % when lysine and arginine were used, respectively. Fourier Transform Infrared spectroscopy showed confirmed the absence of new functional groups or chemical bonds under different treatments, but the absorbance ratio at 1047 cm-1 to 1022 cm-1 was higher in microwave-treated cakes with lysine compared to traditionally steamed cakes. Simulated digestion experiments demonstrated that microwave-treated cakes, especially with added amino acids, exhibited higher protein digestibility but lower starch digestibility. Confocal Laser Scanning Microscopy observations further showed that proteins formed a denser network structure around starch granules during in vitro digestion, suggesting improved protein functionality and structure in microwave-treated quinoa sponge cakes.

Preparation and analysis of quinoa active protein (QAP) and its mechanism of inhibiting Candida albicans from a transcriptome perspective

The globe cultivation and industrial production of quinoa have been steadily increasing. Nevertheless, the full potential of quinoa's nutritional and economic benefits remains underexploited. This study investigates the isolation and purification of quinoa active protein (QAP) through the precipitation method using ammonium sulfate from a phosphate extraction solution. The purification process involved gel filtration chromatography with Sephadex G-75 and Sephadex G-50 columns to obtain QAP fractions exhibiting inhibitory effects against Candida albicans (C. albicans). A comprehensive series of experiments was undertaken to examine the antifungal properties of these fractions. Proteomic analysis was employed to elucidate the composition of the active proteins. Furthermore, the activities of succinate dehydrogenase, Ca2+-Mg2+-ATPase, and catalase in C. albicans following treatment with QAP were quantified using an enzyme-linked immunosorbent assay. The effects of QAP on the cell morphology of C. albicans cultured on Spider agar medium was further investigated using scanning electron microscopy (SEM). Furthermore, RNA-seq analysis was conducted to investigate the alterations in gene expression in C. albicans cells subjected to QAP treatment. To elucidate the functional significance of these expression changes, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed. Quantitative real-time polymerase chain reaction was subsequently employed to validate the observed changes in gene expression. Our findings demonstrate that QAP exhibits inhibitory effects against C. albicans, with a minimum inhibitory concentration of 182 µg/mL. Through proteomic analysis, a definitive set of 18 active quinoa proteins was identified. At the molecular level, genes associated with hyphal development, cell wall and membrane integrity, cellular respiration, and energy metabolism were found to be enriched. Protein-protein interaction (PPI) analysis revealed that these QAP inhibit the growth of C. albicans hyphae, compromise cell wall and membrane integrity, and suppress oxidative phosphorylation. These disruptions collectively impair normal cellular metabolic activities, thereby exerting an inhibitory effect on C. albicans.

Quinoa Polysaccharides: Extraction, Purification, Structure, Functional Properties, and Applications in Food Science and Health

Quinoa polysaccharides have attracted significant research interest in recent years due to their diverse biological activities, including antiviral, anti-inflammatory, antioxidant, and immunoregulatory properties. These attributes align with the growing global demand for natural, functional food ingredients, positioning quinoa polysaccharides as a valuable resource in food science and technology. This review presents an overview of the various bioactivities of quinoa polysaccharides, critically evaluates the methods used for their extraction and purification, describes their structural characteristics, and discusses their practical applications across multiple areas within the food industry, including food additives, meat products, health foods, and innovative food packaging. This study examines the relationship between the preparation methods and the structural characteristics of quinoa polysaccharides, as well as their versatile applications in the food industry, such as improving product quality and shelf life, enhancing nutritional value and antioxidant activity, and providing health benefits in functional foods. This review also emphasizes the need for further research on the emulsification and gelation properties of quinoa polysaccharides and highlights their significant market potential, driven by their diverse functional properties. From our perspective, quinoa polysaccharides, with their wide range of functional and health benefits, hold a promising future in the food and health industries, driven by technological advancements and consumer demands.

Chenopodium quinoa Willd. and Amaranthus hybridus L.: Ancestral Andean Food Security and Modern Anticancer and Antimicrobial Activity

The species Chenopodium quinoa Willd. and Amaranthus hybridus L. are Andean staples, part of the traditional diet and gastronomy of the people of the highlands of Colombia, Ecuador, Peru, Bolivia, northern Argentina and Chile, with several ethnopharmacological uses, among them anticancer applications. This review aims to present updated information on the nutritional composition, phytochemistry, and antimicrobial and anticancer activity of Quinoa and Amaranth. Both species contribute to food security due to their essential amino acid contents, which are higher than those of most staples. It is highlighted that the biological activity, especially the antimicrobial activity in C. quinoa, and the anticancer activity in both species is related to the presence of phytochemicals present mostly in leaves and seeds. The biological activity of both species is consistent with their phytochemical composition, with phenolic acids, flavonoids, carotenoids, alkaloids, terpenoids, saponins and peptides being the main compound families of interest. Extracts of different plant organs of both species and peptide fractions have shown in vitro and, to a lesser degree, in vivo activity against a variety of bacteria and cancer cell lines. These findings confirm the antimicrobial and anticancer activity of both species, C. quinoa having more reported activity than A. hybridus through different compounds and mechanisms.

An Overview of Ingredients Used for Plant-Based Meat Analogue Production and Their Influence on Structural and Textural Properties of the Final Product

Plant-based meat analogues are food products made from vegetarian or vegan ingredients that are intended to mimic taste, texture and appearance of meat. They are becoming increasingly popular as people look for more sustainable and healthy protein sources. Furthermore, plant-based foods are marketed as foods with a low carbon footprint and represent a contribution of the consumers and the food industry to a cleaner and a climate-change-free Earth. Production processes of plant-based meat analogues often include technologies such as 3D printing, extrusion or shear cell where the ingredients have to be carefully picked because of their influence on structural and textural properties of the final product, and, in consequence, consumer perception and acceptance of the plant-based product. This review paper gives an extensive overview of meat analogue components, which affect the texture and the structure of the final product, discusses the complex interaction of those ingredients and reflects on numerous studies that have been performed in that area, but also emphasizes the need for future research and optimization of the mixture used in plant-based meat analogue production, as well as for optimization of the production process.