Biochemical and immunochemical evidences supporting the inclusion of quinoa (Chenopodium quinoa Willd.) as a gluten-free ingredient

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

Quinoa (Chenopodium quinoa Willd.) is a pseudocereal plant that originally came from South America. The trend of consuming quinoa is propelled by its well‒balanced amino acid profile compared to that of other plants. In addition, its gluten‒free nature makes quinoa a promising diet option for celiac disease patients. Protein accounts for approximately 17% of the quinoa seed composition and quinoa protein possesses excellent quality. Quinoa protein is mainly composed of 11S globulins (37%) and 2S albumins (35%), both of which are stabilized by disulfide bonds. To date, the alkaline extraction method is the most commonly used method to extract quinoa protein. The functional properties and digestibility of quinoa protein can be improved with the help of various modification methods, and as a result, the application of quinoa protein will be extended. In this review, the extraction method, modification of functional properties and digestibility of quinoa protein are thoroughly discussed, providing insights into the application of quinoa protein in plant‒based foods.

An overview of the nutritional profile, processing technologies, and health benefits of quinoa with an emphasis on impacts of processing

Consumers are becoming increasingly conscious of adopting a healthy lifestyle and demanding food with high nutritional values. Quinoa (Chenopodium quinoa Willd.) has attracted considerable attention and is consumed worldwide in the form of a variety of whole and processed products owing to its excellent nutritional features, including richness in micronutrients and bioactive phytochemicals, well-balanced amino acids composition, and gluten-free properties. Recent studies have indicated that the diverse utilization and final product quality of this pseudo-grain are closely related to the processing technologies used, which can result in variations in nutritional profiles and health benefits. This review comprehensively summarizes the nutritional properties, processing technologies, and potential health benefits of quinoa, suggesting that quinoa plays a promising role in enhancing the nutrition of processed food. In particular, the effects of different processing technologies on the nutritional profile and health benefits of quinoa are highlighted, which can provide a foundation for the updating and upgrading of the quinoa processing industry. It further discusses the present quinoa-based food products containing quinoa as partial or whole substitute for traditional grains.

Quinoa Snack Production at an Industrial Level: Effect of Extrusion and Baking on Digestibility, Bioactive, Rheological, and Physical Properties

This research aimed to produce gluten-free snacks on a pilot scale from quinoa flour. These snacks experienced an extrusion process, followed by baking. The effects of these technological processes on carbohydrate and protein digestibility, extractable phenolic compounds (EPP), hydrolyzable phenolic compounds (HPP), antioxidant capacity, and physical properties were evaluated in raw quinoa flour and extruded snacks. Extrusion increased digestible starch (RDS) from 7.33 g/100 g bs to 77.33 g /100 g bs. Resistant starch (RS) showed a variation of 2 g/100 g bs. It is noteworthy that protein digestibility increased up to 94.58 g/100 bs after extrusion and baking. These processes increased HPP content, while EPP and carotenoid content decreased. The samples showed significant differences (p < 0.05) in the antioxidant properties determined through the DPPH and ABTS methods. Values of 19.72 ± 0.81 µmol T/g were observed in snacks and 13.16 ± 0.2 µmol T/g in raw flour, but a reduction of up to 16.10 ± 0.68 µmol T/g was observed during baking. The baking process reduced the work of crispness (Wcr) from 0.79 to 0.23 N.mm, while the saturation (C*) was higher in baked ones, showing higher color intensity. The baking process did not influence the viscosity profile. The results in this study respond to the growing interest of the food industry to satisfy consumer demand for new, healthy, and expanded gluten-free snacks with bioactive compounds.

Exploration on bioactive properties of quinoa protein hydrolysate and peptides: a review

Quinoa is an excellent source of nutritional and bioactive components. Protein is considered a key nutritional advantage of quinoa grain, and many studies have highlighted the nutritional and physicochemical properties of quinoa protein. In addition, quinoa protein is a good precursor of bioactive peptides. This review focused on the biological properties of quinoa protein hydrolysate and peptides, and gave a summary of the preparation and functional test of quinoa protein hydrolysate and peptides. A combination of milling fractionation and solvent extraction is recommended for the efficient production of quinoa protein. The biological functionalities of quinoa protein hydrolysate, including antidiabetic, antihypertensive, anti-inflammatory, antioxidant activities, and so on, have been extensively investigated based on in vitro studies and limited animal models. Additionally, bioinformatics analysis, including proteolysis simulation, virtual screening, and molecular docking, provides an alternative or assistive approach for exploring the potential bioactivity of quinoa protein and peptides. Nevertheless, further research is required for industrial production of bioactive quinoa peptides, verification of health benefits in humans, and mechanism interpretation of observed effects.

Studying the Impact of Different Field Environmental Conditions on Seed Quality of Quinoa: The Case of Three Different Years Changing Seed Nutritional Traits in Southern Europe

Chenopodium quinoa Willd (quinoa) has acquired an increased agronomical and nutritional relevance due to the capacity of adaptation to different environments and the exceptional nutritional properties of their seeds. These include high mineral and protein contents, a balanced amino acid composition, an elevated antioxidant capacity related to the high phenol content, and the absence of gluten. Although it is known that these properties can be determined by the environment, limited efforts have been made to determine the exact changes occurring at a nutritional level under changing environmental conditions in this crop. To shed light on this, this study aimed at characterizing variations in nutritional-related parameters associated with the year of cultivation and different genotypes. Various nutritional and physiological traits were analyzed in seeds of different quinoa cultivars grown in the field during three consecutive years. We found differences among cultivars for most of the nutritional parameters analyzed. It was observed that the year of cultivation was a determinant factor in every parameter studied, being 2018 the year with lower yields, germination rates, and antioxidant capacity, but higher seed weights and seed protein contents. Overall, this work will greatly contribute to increase our knowledge of the impact of the environment and genotype on the nutritional properties of quinoa seeds, especially in areas that share climatic conditions to Southern Europe.

Pseudocereal grains: Nutritional value, health benefits and current applications for the development of gluten-free foods

Nowadays, consumers are more conscious of the environmental and nutritional benefits of foods. Pseudocereals grains, edible seeds belonging to dicotyledonous plant species, are becoming a current trend in human diets as gluten-free (GF) grains with excellent nutritional and nutraceutical value. Pseudocereals are a good source of starch, fiber, proteins, minerals, vitamins, and phytochemicals such as saponins, polyphenols, phytosterols, phytosteroids, and betalains with potential health benefits. The present review aims to summarize the nutritional quality and phytochemical profile of the three main pseudocereal grains: quinoa, amaranth and buckwheat. In addition, current evidence about their health benefits in animal models and human studies is also provided in detail. Based on the accumulating research supporting the inclusion of pseudocereals grains in the diet of celiac persons, this review discusses the recent advances in their application for the development of new GF products. Future directions for a wider cultivation and commercial exploitation of these crops are also highlighted.

Lactic Fermentation as a Strategy to Improve the Nutritional and Functional Values of Pseudocereals

One of the greatest challenges is to reduce malnutrition worldwide while promoting sustainable agricultural and food systems. This is a daunting task due to the constant growth of the population and the increasing demands by consumers for functional foods with higher nutritional values. Cereal grains are the most important dietary energy source globally; wheat, rice, and maize currently provide about half of the dietary energy source of humankind. In addition, the increase of celiac patients worldwide has motivated the development of gluten-free foods using alternative flour types to wheat such as rice, corn, cassava, soybean, and pseudocereals (amaranth, quinoa, and buckwheat). Amaranth and quinoa have been cultivated since ancient times and were two of the major crops of the Pre-Colombian cultures in Latin- America. In recent years and due to their well-known high nutritional value and potential health benefits, these pseudocereals have received much attention as ideal candidates for gluten-free products. The importance of exploiting these grains for the elaboration of healthy and nutritious foods has forced food producers to develop novel adequate strategies for their processing. Fermentation is one of the most antique and economical methods of producing and preserving foods and can be easily employed for cereal processing. The nutritional and functional quality of pseudocereals can be improved by fermentation using Lactic Acid Bacteria (LAB). This review provides an overview on pseudocereal fermentation by LAB emphasizing the capacity of these bacteria to decrease antinutritional factors such as phytic acid, increase the functional value of phytochemicals such as phenolic compounds, and produce nutritional ingredients such as B-group vitamins. The numerous beneficial effects of lactic fermentation of pseudocereals can be exploited to design novel and healthier foods or grain ingredients destined to general population and especially to patients with coeliac disease.

Yield and Quality Characteristics of Different Quinoa (Chenopodium quinoa Willd.) Cultivars Grown under Field Conditions in Southwestern Germany

Due to its highly nutritive compounds, the demand for quinoa, a small grain originating from the Andean region of South America, increased rapidly over the last years. However, the main producing countries Bolivia and Peru cannot cover the growing demand. Therefore, the interest of European farmers in cultivating quinoa as a profitable source of income rose very fast. Thanks to a broad genetic diversity an adaption to various climatic conditions is possible. The objective of this study was to evaluate the stability of agronomic performance in two consecutive growing periods (2015 and 2016) of four European quinoa cultivars (Puno, Titicaca, Jessie, Zeno), originating from different genepools to identify a suitable cultivar to grow in southwestern Germany. Measurements included grain yield, thousand kernel weight (TKW), saponin content, protein content, crude fat content, amino acid profile and fatty acid profile. This study demonstrated the possibility of an economic production of quinoa under the environmental conditions in southwestern Germany, combining competitive yields (1.73–2.43 Mg ha−1) with a high grain quality regarding protein content (11.9–16.1%), essential amino acid content (20.35–30.02 g 100 g−1 crude protein), fat content (5.5–7.5%) and fatty acid profile (consists of 60% linoleic acid). Depending on cultivar, the investigated yield (TKW and protein content)-and quality ((semi-)essential amino acids)-traits varied more or less sensitive, which was attributed to lower precipitation and higher temperatures in 2015. Furthermore, best yield- and quality-characteristics were not combined in one cultivar, wherefore the selection of a specific quinoa cultivar has to be aligned with the production aim.

In Vitro Screening of Bioactive Compounds in some Gluten-Free Plants

Electrophoretic, antioxidant, and FTIR profiles of some varieties of amaranth, quinoa, and buckwheat seeds and their by products were compared. Water extracts of these products were evaluated by the Folin-Ciocalteau method in order to determine total phenolic content. The antioxidant activities were determined by 2,2'-azobis-2-methyl-propanimidamide, ferric-reducing/antioxidant power, and cupric reducing antioxidant capacity radical scavenging assays. FTIR spectra showed the secondary structure of pseudocereals in the ranges of amides I, II, and III shifts. Results of evaluated methods could be used to control several products (seeds, flours, extracts, flakes, roasting) with high phenolic content and antioxidant activity suitable for supplementation in food applications. Graphical Abstract ᅟ.

Digestibility of Quinoa (Chenopodium quinoa Willd.) Protein Concentrate and Its Potential to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model

Quinoa protein concentrate (QPC) was extracted and digested under in vitro gastrointestinal conditions. The protein content of QPC was in the range between 52.40 and 65.01% depending on the assay used. Quinoa proteins were almost completely hydrolyzed by pepsin at pH of 1.2, 2.0, and 3.2. At high pH, only partial hydrolysis was observed. During the duodenal phase, no intact proteins were visible, indicating their susceptibility to the in vitro simulated digestive conditions. Zebrafish larvae model was used to evaluate the in vivo ability of gastrointestinal digests to inhibit lipid peroxidation. Gastric digestion at pH 1.2 showed the highest lipid peroxidation inhibition percentage (75.15%). The lipid peroxidation activity increased after the duodenal phase. The digest obtained at the end of the digestive process showed an inhibition percentage of 82.10%, comparable to that showed when using BHT as positive control (87.13%).

Chemical characterization, antioxidant, immune-regulating and anticancer activities of a novel bioactive polysaccharide from Chenopodium quinoa seeds

Chenopodium quinoa, a promising nutraceutical cereal, has attracted increasing research interest, yet its polysaccharides remains to get few systematic studies. In this study, we employed orthogonal experimental design to optimize the ultrasound-assisted extraction process for highest yield of C. quinoa polysaccharides. A novel C. quinoa polysaccharide (CQP) fraction with high content and low molecular weight (8852Da) was subsequently purified by column chromatography, constituted by galacturonic acid and glucose monosaccharides. The purified CQP exhibited significantly antioxidant effect against DPPH⁺ and ABTS⁺, with even higher efficiency than some other reported polysaccharides. Moreover, CQP could promote the RAW264.7 macrophage proliferation, while suppress the nitri oxide production on inflammatory RAW264.7 macrophage in a dose- and time-dependent manner. In view of the pathological correlation of free radical, inflammation and carcinogenesis, the anticancer effect of CQP was further investigated on human liver cancer SMMC 7721 and breast cancer MCF-7 cells. Interestingly, CQP displayed cytotoxicity against cancer cells, while none proliferation inhibition on normal cells. These results suggest that the bioactive polysaccharide from C. quinoa provided the promising potential as a natural antioxidant, immune-regulating and anticancer candidate for food and even drug application.

Ancestral Andean grain quinoa as source of lactic acid bacteria capable to degrade phytate and produce B-group vitamins

The lactic acid bacteria (LAB) microbiota of quinoa grains (QG) and spontaneous sourdough (QSS) was evaluated. Different strains of Lactobacillus (L.) plantarum (7), L. rhamnosus (5), L. sakei (1), Pediococcus (Ped.) pentosaceus (9), Leuconostoc (Leuc.) mesenteroides (1), Enterococcus (E.) casseliflavus (2), E. mundtii (3), E. hirae (1), E. gallinarum (12), Enterococcus sp. (1), and E. hermanniensis (2) were isolated, identified and characterized. Only four strains isolated from QSS and eight strains isolated from QG showed amylolytic activity. L. plantarum CRL 1973 and CRL 1970, L. rhamnosus CRL 1972 and L. sakei CRL 1978 produced elevated concentrations of folate with strain CRL 1973 producing the highest concentration (143±6ng/ml). L. rhamnosus, isolated from QSS, was the LAB species that produced the most elevated concentrations of total riboflavin (>270ng/ml) with strain CRL 1963 producing the highest amounts (360±10ng/ml). Phytase activity, evaluated in forty-four LAB strains from quinoa, was predominantly detected in L. rhamnosus and Enterococci strains with the highest activities observed in E. mundtii CRL 2007 (957±25U/ml) followed by E. casseliflavus CRL 1988 (684±38U/ml), Leuc. mesenteroides CRL 2012 (617±38U/ml) and L. rhamnosus CRL 1983 (606±79U/ml). In conclusion, this study shows that a diverse LAB microbiota is present in quinoa with important properties; these microorganisms could be used as potential starter cultures to increase the nutritional and functional properties of Andean grains based foods.

The gluten-free basic food basket: a problem of availability, cost and nutritional composition

The basic food basket (BFB), formed by the more economical products available, is used by less-affluent countries to establish the minimum daily food consumption to satisfy nutritional requirements in less-privileged individuals. There is no information about groups that depend on the BFB and in addition follow gluten-free diet (GF/BFB). We measured availability, cost, main ingredients and nutritional composition of GF/BFB. Data were collected in the area that was first in the social priority list in the capital city, matching BFB components with gluten-free equivalents (GF/BFB). GF/BFB characterized by being 42% less available, three times more costly (>500% higher for bread), with up to 69% lower protein content and with no fortifications, leaving at nutritional risk celiac individuals that depend on GF/BFB. Results raise concerns on the capacity of the GF/BFB to encourage adherence, maintain adequate nutritional status and quality of life in celiac patients.

Impact of Elicitation on Antioxidant and Potential Antihypertensive Properties of Lentil Sprouts

The aim of this study was to investigate the application of elicitors (500 μM ascorbic acid, 50 μM folic acid, 5 mM glutamic acid and 50 ppm chitosan in 5 mM glutamic acid) during lentil germination up to 8 days as a strategy to increase germination rate and to enhance the accumulation of γ-aminobutyric acid (GABA) and phenolic compounds. The effect of elicitation on the protein profile and antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities of sprouted lentils was also evaluated. The application of elicitors did not negatively affect the germination yield of lentils and no significant changes on the protein pattern of lentils germinated in the presence of elicitors were observed. Chitosan/glutamic acid increased by 1.6-fold the GABA content in lentil sprouts, whilst ascorbic and folic acids as well as chitosan/glutamic acid were highly effective to enhance the total content of phenolic compounds and the antioxidant activity of sprouted lentils. All elicited lentil sprouts showed ability to inhibit ACE activity (IC50: 9.5-11.9 μg peptides/mL). Therefore, elicitation can be considered a promising approach to improve the content of compounds with antioxidant and potential antihypertensive activities in lentil sprouts.

Modifying the Cold Gelation Properties of Quinoa Protein Isolate: Influence of Heat-Denaturation pH in the Alkaline Range

Heat-denaturation of quinoa protein isolate (QPI) at alkali pH and its influence on the physicochemical and cold gelation properties was investigated. Heating QPI at pH 8.5 led to increased surface hydrophobicity and decreases in free and bound sulfhydryl group contents. Heating at pH 10.5 caused a lesser degree of changes in sulfhydryl groups and surface hydrophobicity, and the resulting solutions showed drastically increased solubility. SDS PAGE revealed the presence of large aggregates only in the sample heated at pH 8.5, suggesting that any aggregates present in the sample heated at pH 10.5 were non-covalently bound and disintegrated in the presence of SDS. Reducing conditions partially dissolved the aggregates in the pH 8.5 heated sample indicating the occurrence of disulphide bonding, but caused no major alterations in the separation pattern of the pH 10.5 heated sample. Denaturation pH influenced the cold gelation properties greatly. Solutions heated at pH 8.5 formed a coarse coagulum with maximum G' of 5 Pa. Heat-denaturation at 10.5 enabled the proteins to form a finer and regularly structured gel with a maximum G' of 1140 Pa. Particle size analysis showed that the pH 10.5 heated sample contained a higher level of very small particles (0.1-2 μm), and these readily aggregated into large particles (30-200 μm) when pH was lowered to 5.5. Differences in the nature of aggregates formed during heating may explain the large variation in gelation properties.