Quinoa Grains Research Articles

A Long Journey of CICA-17 Quinoa Variety to Salinity Conditions in Egypt: Mineral Concentration in the Seeds.

Quinoa may be a promising alternative solution for arid regions, and it is necessary to test yield and mineral accumulation in grains under different soil types. Field experiments with Chenopodium quinoa (cv. CICA-17) were performed in Egypt in non-saline (electrical conductivity, 1.9 dS m−1) and saline (20 dS m−1) soils. Thirty-four chemical elements were studied in these crops. Results show different yields and mineral accumulations in the grains. Potassium (K), P, Mg, Ca, Na, Mn, and Fe are the main elements occurring in the quinoa grains, but their concentrations change between both soil types. Besides, soil salinity induced changes in the mineral pattern distribution among the different grain organs. Sodium was detected in the pericarp but not in other tissues. Pericarp structure may be a shield to prevent sodium entry to the underlying tissues but not for chloride, increasing its content in saline conditions. Under saline conditions, yield decreased to near 47%, and grain sizes greater than 1.68 mm were unfavored. Quinoa may serve as a complementary crop in the marginal lands of Egypt. It has an excellent nutrition perspective due to its mineral content and has a high potential to adapt to semi-arid and arid environments.

Kinetics of temperature and time effects on bioactive compounds and technological properties of quinoa varieties during storage

This study aimed to assess the kinetics and the changes in bioactive compounds, color, and technological properties of Mint Vanilla and Titicaca quinoa varieties stored during 360 days at 4, 10, and 25°C. It was observed that an increase in the storage time and temperature decreased the total phenolics (except at 25°C for Mint Vanilla), total flavonoids, DPPH, and FRAP contents of both quinoa varieties. After 360 days of storage, it was determined that storage conditions had a significant (p < .05) effect on technological properties. Color change was affected by storage time and temperature, with the most prominent influence observed after the 60 days of storage. It was determined that there were losses in the kinetic study of all the properties investigated. The activation energy of Mint Vanilla and Titicaca varied from 6.61 to 50.36 and 8.15 to 74.11 kJ/mol, respectively. Practical applications In the period of harvest, grain production exceeds the market demand. Therefore, most farmers store their production into storage structures to maintain quality of quinoa grains until releasing into the market. In this context, the effects of different storage conditions on the quality and technological properties of two quinoa varieties were investigated. The storage at 4 and 10°C provides the best preservability of the grains throughout the 360 days storage, verified by bioactive compounds, color, and technological properties.

Физиолого-биохимическая оценка эффективности нового пищевого ингредиента: источника фитоэкдистероидов и флавоноидов из зерна киноа

Abstract- One of the promising food sources of biologically active substances is quinoa grain, which is valued for its high content of protein, sulfur-containing amino acids, lysine, fiber, and minerals. In addition, quinoa grain can be a valuable food source of polyphenolic compounds and phytoecdysteroids. The method for production of a concentrate of flavonoids and 20-hydroxyecdysone from quinoa grains sorbed on coagulated egg protein has been developed. The in vivo evaluation of efficacy of the developed food ingredient was conducted using male Wistar rats under immobilization stress and after exhausting physical exertion. The consumption of the food ingredient prevented an increase in the level of the main stress markers, catecholamines, in animals subjected to immobilization stress. The opposite effect was observed in animals that received the food ingredient after exhausting physical exertion: their levels of catecholamines were significantly higher than in the rest comparison groups. Using the Elevated Plus Maze and Open Field tests, it was shown that the consumption of the developed concentrate neutralized the negative effect of immobilization stress and treadmill exercise on anxiety in Wistar rats. The results obtained require additional study under conditions of preventive introduction of the food ingredient into the diet of intact animals, as well as a toxicological safety assessment. Key words: quinoa, 20-hydroxyecdysone, flavonoids, stress, immobilization, exhaustive physical exercise, catecholamines, corticosterone This work was supported by the Russian Scientific Foundation, grant no. 19-16-00107.

Effects of arsenite on physiological, biochemical and grain yield attributes of quinoa (Chenopodium quinoa Willd.): implications for phytoremediation and health risk assessment

The objectives of this study were to investigate the effects of arsenic (As) on physiological and biochemical attributes of quinoa, and human health risks associated with the consumption of As contaminated grains of quinoa. Quinoa genotype, Puno was grown on soil contaminated with various levels of arsenite; 0, 10, 20, 30, and 40 mg As kg−1 soil. Results revealed that plant growth, photosynthetic pigments, stomatal conductance, and grain yield of As treated plants were significantly less as compared to control plants. Plants exposed to elevated levels of 30 and 40 mg As kg−1 of soil could not survive until maturity. Plant roots retained higher concentration of As than shoot indicating As phytostabilizing behavior of quinoa. Arsenic toxicity caused oxidative stress in quinoa plants, which elevated the H2O2 and TBARS contents and decreased membrane stability. This oxidative stress was partly mitigated by the induction of antioxidant enzymes (SOD, CAT, POD, APX). Perhaps, our results regarding As availability might be an overestimate of the typical natural conditions, As accumulation in quinoa grains posed both carcinogenic and non-carcinogenic health risks to humans. It was concluded that quinoa is sensitive to As and the consumption of quinoa grains from plants grown on As concentration ≥20 mg kg−1 of soil was not safe for humans. Novelty statement: The tolerance potential of quinoa (Chenopodium quinoa Willd.) against the trivalent form of arsenic (arsenite), and the health risks due to the consumption of arsenic-contaminated grains has not been explored yet. This is the first study in which we have explored the effects of arsenite on physiological, biochemical and phytoremedial attributes of quinoa. Moreover, human health risks associated with the consumption of As contaminated grains of quinoa has have been investigated. The findings of the present study would be helpful for farmers who intend to grow quinoa on arsenic-contaminated soils.

Maceração de grãos de Chenopodium quinoa Willd: efeito do tempo e temperatura

A quinoa tem despertado o interesse mundial por seu alto valor nutritivo, principalmente em relação ao teor de proteínas. Diante disso, o objetivo deste estudo foi avaliar o efeito do tempo e temperatura na maceração da quinoa visando obter maior encharcamento com menor perda de proteínas do grão. Para caracterização dos grãos de quinoa o material foi triturado e submetido as análises de umidade, proteínas, lipídios e cinzas. Para avaliação do tempo e temperatura, os grãos foram macerados em três temperaturas diferentes (5 oC, 25 oC e 45 oC) na proporção 1:2 (quinoa:água) durante 48 horas. Amostras da água de maceração foram submetidas as análises de potencial hidrogeniônico, determinação de proteínas, acidez e absorção de água. O experimento foi conduzido no Delineamento em Parcela Subdividida com a temperatura na parcela (3 níveis – 5 oC, 25oC e 45oC) com três repetições e o tempo de maceração na subparcela (9 níveis – 9 tempos). Todas as análises foram realizadas em duplicata. Em relação aos resultados obtidos, a quinoa pode ser considerada um alimento com alto teor de proteínas (14,35%). Nota-se que a migração das proteínas para a água de maceração é maior na temperatura de 45 oC. Os resultados para o comportamento do pH e acidez mostram que houve fermentação nas temperaturas de 25 e 45 °C. O ganho de massa é independente da temperatura e atingiu um ponto de encharcamento máximo em torno de 16 horas. Assim recomenda-se a maceração da quinoa em uma temperatura de 5 °C por 16 horas.

Moisture sorption isotherm and thermodynamic analysis of quinoa grains

In literature, most studies have only focused on sorption characteristics of quinoa grains. This study is one of the limited studies that deal with the sorption properties of quinoa with a thermodynamic approach. In the designed study, the equilibrium moisture content of whole quinoa grains determined by the static gravimetric method and ten different sorption models were applied for the description of the relationship between detected water activity and equilibrium moisture content. The thermodynamical properties of sorption have been determined by calculation of isosteric heat, entropy, Gibb’s free energy and spreading pressure. The best fitted sorption models are Brunauer–Emmett–Teller, Henderson, Peleg and Smith according to the statistical significance parameters. The monolayer moisture content of quinoa grains varies between 3.72–5.25%. The adsorption isotherm of grains are classified in Type-II by giving a sigmoidal shape. According to the thermodynamical analysis, the increase in moisture content leads to a decrease in isosteric heat of sorption from 50.4 kJ/mol to 43.7 kJ/mol. Additionally, the reduction in sorption heat is more gradual after 8% moisture content. Like isosteric heat of sorption, sorption entropy decreases from 15.9 J/molK to 1.5 J/molK with increasing water activity. Spreading pressure which means the surface excess-free energy, has ranged between 0.01 and 0.15 J/m2 and increase with water activity. Increasing moisture contents and temperatures have also decreased Gibb’s free energy level.

Non-targeted metabolomics of quinoa seed filling period based on liquid chromatography-mass spectrometry

Quinoa (Chenopodium quinoa Willd.), an herb belonging to the amaranth family, is rich in minerals, amino acids, vitamins, proteins, and flavonoids. Its grain, compared with other major grains, has unique nutritional value with tremendous applications. This study used four independently bred high-generation lines (seed colors) of quinoa as materials to further understand the metabolic differences in the filling periods of quinoa varieties. Additionally, the non-targeted metabolome of quinoa seeds 35 and 42 days after flowering, respectively, were studied via liquid chromatography-mass spectrometry. The two filling periods of yellow, white, black, and red quinoa grains resulted in significant differences in the metabolites, particularly in L-methionine, S-adenosyl-L-homocysteine, S-adenosyl-L-methionine, pyruvate, fumarate, and oxaloacetate. Soluble sugar, amino acid, and fatty acid contents in quinoa increased after 42 days of flowering. There were metabolic differences between the sugar phosphates (L-fucose, D-mannose-6-phosphate, xylulose-5-phosphate, sedoheptulose-7-phosphate), amino acid (alanine), and organic compounds (kynurenate, tryptamine, serotonin, bilirubin) among the four quinoa varieties. The relative difference in the metabolites was largest when the yellow quinoa grain was compared with the other quinoa varieties and smallest when the red and black varieties were compare. The results of this study provide a basis for the reproduction and identification of new quinoa varieties, as well as for screening potential quality control target genes by combining genomics and transcriptomics.

基于堆积试验的藜麦离散元参数分析及标定

An optimization method based on a regression model was established by combining physical experiments, and an extended distinct element method (EDEM) simulation was proposed to address the difficult problem of obtaining the contact characteristic parameters used in the discrete element method (DEM) model of quinoa grains and for calibrating the parameters of the quinoa DEM model. The Plackett-Burman test was designed using Design-Expert software to screen the parameters of the quinoa DEM model, and the quinoa-quinoa static friction coefficient, quinoa-polylactic acid (PLA) static friction coefficient and quinoa-quinoa rolling friction coefficient were found to have significant effects on the repose angle. The optimal value intervals of the parameters with a significant impact on the repose angle were determined using the steepest ascent test. A regression model of the repose angle and the parameters with a significant impact on the repose angle was then established with the Box-Behnken design and further optimized, and the combination of optimal parameters was as follows: 0.26 for the quinoa-quinoa static friction coefficient (E), 0.38 for the quinoa-PLA static friction coefficient (F), and 0.08 for the quinoa-quinoa rolling friction coefficient (G). Lastly, the optimal combination was used in the verification performed by the DEM simulation, and the error between the simulated repose angle and the target repose angle was 0.86%. These findings indicated that it was feasible to use the response surface optimization to calibrate the parameters required for quinoa DEM simulation and that the combination of optimal parameters can provide a reference for selecting the characteristic contact parameters used in quinoa DEM simulation.

Effect of processing on the contents of amino acids and fatty acids, and glucose release from the starch of quinoa.

The effects of processing on the content of amino acids and fatty acids and the release of glucose from quinoa grains were evaluated in this paper. The processes included dehulling, boiling, extrusion, heating under pressure, and baking (infrared heating). The retention rate (AR) of essential amino acids and fatty acids of dehulled and boiled quinoa was 100%. The oil content of the extruded quinoa samples of two varieties was 47.71% and 39.75% lower than the corresponding raw quinoa samples. Baking and heating under pressure had different effects on the essential amino acid content, fatty acid content, and hydrolysis rate of quinoa starch. The results indicated the different cooking methods affect the essential amino acid content, fatty acid composition, release of glucose, and nutritional quality of quinoa, and moderate processing should be adopted to fully utilize the essential amino acids, fatty acids, and starch in quinoa.

Chenopodium quinoa Willd. (quinoa) grains: A good source of phenolic compounds

The ingestion of bioactive compounds has revealed health benefits, namely in the prevention and/or treatment of several diseases. This work aims to characterize the phenolic profile of three colour varieties of Chenopodium quinoa Willd. grains (black, red and white), and also evaluate their cytotoxic and antimicrobial activity. All varieties revealed the presence of phenolic compounds, namely, quercetin and kaempferol derivatives. In this study, quinoa grains did not reveal any anti-proliferative capacity in tumour cell lines, and, as expected, they were devoid of any toxicity. All of the analysed extracts possessed antibacterial and antifungal activities (inhibitory and bactericidal/fungicidal) against the microbial strains considered, exhibiting promising values of minimum bactericidal concentrations (mean MBC 0.153–0.916 mg/mL) and minimum fungicidal concentrations (mean MFC 0.211–0.884 mg/mL). Quinoa varieties represent a good source of bioactive compounds, interfering beneficially in the organism, specifically as antimicrobial agents. Thus, these extracts could be used in the development of bioactive ingredients.

Optimization of Sand Puffing Characteristics of Quinoa using Response Surface Methodology

The superfood quinoa is an extremely nutritious and ancient pseudocereal grain particularly known for its protein quality and bioactive compounds, compared to other cereals. Quinoa seeds can be processed into a crispy, cellular-structured and expanded whole-grain snack product by low capital cost involving traditional sand puffing method. The study aims to statistically optimize the processing conditions for sand puffing of quinoa. The moisture-treated and salt-treated quinoa grains were mixed with a high-temperature sand bed for a predetermined time to induce grain expansion. Puffing conditions were optimized using Box-Behnken design by varying the factors such as moisture added (0.2-1.8 ml/10 g grains), salt concentration (0-1%), puffing temperature (200-240 ºC) and puffing time (20-60 s). It was found that measured response parameters like puffing yield, expansion ratio, flake size and overall acceptability of puffed quinoa significantly (p&lt;0.05) increased with a decrease in moisture added and salt concentration, and increase in puffing temperature and puffing time. Bulk density of puffed quinoa had a negative correlation with puffing temperature and puffing time. The optimum condition of 0.2 ml moisture added/10 g grains, 0.2% salt concentration, 229ºC puffing temperature and 55 s puffing time was predicted to generate puffing yield of 86.23%, expansion ratio of 3.08, flake size of 8.21 mm3, bulk density of 0.36 g/ml and overall acceptability score of 8.65. The higher yield, three-fold expansion and superior sensory attributes of puffed quinoa achieved from optimized sand puffing condition would benefit the manufactures and be nutritious snack food for consumers to combat malnutrition.

Safeguarding of quinoa beverage production by fermentation with Lactobacillus plantarum DSM 9843

Plant-based beverages are increasing in popularity and quinoa is an attractive option. A hygienic implication linked to the production of beverages from raw material originating from plants is the high microbial contamination. The safety of the product can be guaranteed by lactic acid fermentation, and by using a probiotic strain as starter culture for the fermentation, the final product will benefit from a high number of live probiotics. In this study, a commercial probiotic strain was used for fermentation of a quinoa-based beverage.White quinoa grains were boiled, mixed with water and pasteurized before the beverage was fermented by Lactobacillus plantarum DSM 9843 at 30 °C for 2 days and then stored at 4 °C for 28 days. pH and production of D- and L-lactic acid were monitored, and viable counts were performed for total aerobes, Lactobacillus and Enterobacteriaceae. Colonies from countable plates were randomly picked and in total 335 isolates were identified by 16S rRNA gene sequencing.After heat treatment isolates of Enterobacter, Salmonella, Escherichia, Pantoea, Enterococcus, Klebsiella, and Leclercia were found in the heat-treated but unfermented quinoa beverage.After fermentation pH has decreased below 4, Enterobacteriaceae count was below detection limit and the Lactobacillus count was high 10.6 log CFU/ml (10.3–10.8) (p = 0.002 compared to inoculated counts). During storage pH and the concentration of lactic acid remained stable but after 28 days the lactobacilli count had decreased to 6.9 (6.6–7.2) (p = 0.065 compared to inoculated counts). The majority of isolates picked from Rogosa and Tryptic Soy Agar was identified as Lactobacillus plantarum but 19% and 6% were identified as Enterococcus mudtii and Pediococcus pentosaceous, respectively.The fermentation process applied improved the safety and stability of the product and fortified it with a high content of live probiotics.A safety problem is the spontaneous growth of enterococci (Enterococcus mudtii) during fermentation, enterococci originating from the native quinoa. A solution to this problem can be to increase the rate of the lactic acid fermentation, e.g. by using a higher inoculum of a more active starter culture, and/or to use a starter culture more antagonistic toward enterococci.

Spinach and quinoa - prospective food sources of biologically active substances

Formally, phytoadaptogens extracted mainly from medicinal plants are not food substances, and their use in preventive nutrition is significantly limited. However, screening studies can detect phytoadaptogens in food plants, however in much smaller quantities. For example, phytoecdysteroids are biologically active substances (BAS), used to relieve chronic fatigue syndrome, reduce nervous and muscle fatigue, improve memory and attention processes. Phytoecdysteroids can be isolated not only from various medicinal plants, but also from food plants like spinach (Spinacia oleracea) and quinoa (Chenopōdium quīnoa). Researchers show interest in possible synergies in the manifestation of a wide range of pharmacological effects, determined by a combination of phytoecdysteroids and other biologically active substances of these food plants. The aim of this research is a brief analytical review of publications characterizing the spectrum of minor biologically active substances of spinach and quinoa, as well as those devoted to the experimental assessment of their pharmacological activity in experiments on laboratory animals. Results. An analysis of the publications presented in the review indicates that spinach and its extracts are promising food sources of phytoadaptogens, carotenoids, phenolic compounds, in particular quercetin, kempferol, phenolic acids (p-coumaric, ferulic), as well as lignans metabolized into biologically active phytoestrogens (enterolactone and enterodiol). The possible prophylactic effect of spinach is being actively studied in vivo in laboratory animals when modeling diseases such as diabetes mellitus, cardiovascular and cancer diseases. Numerous adaptogenic effects and the neuroprotective effect of spinach and its extracts are shown, expressed in improving the memory and learning of animals. Publications of the last decade indicate an increased interest in such a promising food source of high-grade protein and a wide spectrum of biologically active substances, including phytoecdysteroids, as quinoa grains. More than 20 phenolic compounds in free or conjugated forms were found in quinoa grains; tannins, saponins, sterols, phytic acid, and ecdysteroids are present in small quantities. The consumptionof quinoa can have a beneficial effect on the organism, normalizing carbohydrate and lipid metabolism, reducing body weight and preventing excessive lipid peroxidation. The anti-inflammatory effects and antioxidant effects of quinoa are widely discussed. Conclusion. Spinach, quinoa and their extracts are promising food sources of biologically active substances, their pharmacological action is confirmed from the standpoint of evidence-based medicine by in vivo experimental studies. Accordingly, it is advisable to expand the use of these food plants for inclusion in biologically active dietary supplements, functional food ingredients and specialized food products for various purposes.

In Vitro Assay of Quinoa (Chenopodium quinoa Willd.) and Lupin (Lupinus spp.) Extracts on Human Platelet Aggregation.

Cardiovascular disease (CVD) is the leading cause of death throughout the world. A major risk factor for CVD is platelet aggregation. Various plant extracts exhibit anti-aggregatory action in vitro. The dietary intake of traditional plant crops such as quinoa (Chenopodium quinoa Willd) and lupin (Lupinus spp., Fabaceae family), highly recognized for their high nutritional value, is increasing worldwide. The aim of the study was to assay possible antiplatelet effects of quinoa and lupin bean extracts in vitro. The proximate chemical composition of quinoa grains and the three most widely known lupin cultivars: blue (L. angustifolius), yellow (L. luteus or mutabilis) and white (L. albus) grown in Chile were analyzed. The anti-aggregation activity of the ethanol extracts of the crops was assayed using flow cytometry in ADP-stimulated human platelets, and their inhibition of the maximal platelet aggregation was measured. All the lupin extracts exhibited a significant anti-aggregatory effect (p< 0.0001), while quinoa extracts did not exert this effect compared to control platelets. In conclusion, lupin beans extracts exhibited an anti-aggregatory effect on activated human platelets.

Quinoa (Chenopodium quinoa Willd.): An Overview of the Potentials of the "Golden Grain" and Socio-Economic and Environmental Aspects of Its Cultivation and Marketization.

Quinoa (Chenopodium quinoa Willd.) is native to the Andean region and has attracted a global growing interest due its unique nutritional value. The protein content of quinoa grains is higher than other cereals while it has better distribution of essential amino acids. It can be used as an alternative to milk proteins. Additionally, quinoa contains a high amount of essential fatty acids, minerals, vitamins, dietary fibers, and carbohydrates with beneficial hypoglycemic effects while being gluten-free. Furthermore, the quinoa plant is resistant to cold, salt, and drought, which leaves no doubt as to why it has been called the “golden grain”. On that account, production of quinoa and its products followed an increasing trend that gained attraction in 2013, as it was proclaimed to be the international year of quinoa. In this respect, this review provides an overview of the published results regarding the nutritional and biological properties of quinoa that have been cultivated in different parts of the world during the last two decades. This review sheds light on how traditional quinoa processing and products evolved and are being adopted into novel food processing and modern food products, as well as noting the potential of side stream processing of quinoa by-products in various industrial sectors. Furthermore, this review moves beyond the technological aspects of quinoa production by addressing the socio-economic and environmental challenges of its production, consumption, and marketizations to reflect a holistic view of promoting the production and consumption of quinoa.

Protein and lipid enrichment of quinoa (cv.Titicaca) by dry fractionation. Techno-functional, thermal and rheological properties of milling fractions

The quality of quinoa flour is greatly determined by its non-starch components, mainly protein and lipids. Dry fractionation has an important impact on the composition and physicochemical properties of quinoa flour and grits. Quinoa cv. Titicaca, the most extensively grown in Europe and little studied so far, was used in this work. Hydration, techno-functional, rheological and thermal properties of three quinoa fractions obtained by dry fractionation (fine, medium and coarse) were evaluated and related to their particle size and composition. The medium fraction (~500 μm) was enriched in protein (50%) and lipids (80%) and depleted in starch (30%) with respect to the original grain; while the coarse fraction (~1000 μm) was enriched in starch (7%) and reduced in protein (15%). The fine fraction showed the most similar functional, pasting and rheological properties to the whole grain quinoa flour. The coarse fraction led to the most consistent gels, with the elastic (G′) and viscous (G'') moduli being ten and twenty times higher than those found in the other quinoa fractions and the whole grain flour. The degree of retrogradation as well as the formation of the amylose-lipid complex were markedly affected by the particle size and not so by the composition of each fraction. This work allows to conclude that dry fractionation of quinoa grains is a feasible procedure to tailoring the nutritional profile of the flour and its techno-functional and rheological properties.

Alleviation of Salinity Induced Oxidative Stress in Chenopodium quinoa by Fe Biofortification and Biochar—Endophyte Interaction

Iron-biofortification is a sustainable food-based approach to combat iron deficiency by increasing iron content and bioavailability in agronomic crops. Siderophore producing microbes offer a sustainable and low-cost way to increase iron supply in crops. Also, certain substances released from organic amendments act as iron-chelators which increase the solubility as well as the availability of iron to plants. Present study investigated the role of siderophore-producing endophytic bacteria and biochar on iron-fortification of a novel crop quinoa in iron-limited saline conditions. The surface-disinfected seeds of quinoa were inoculated with Burkholderia phytofirmans PsJN (CFU = 109) and sown in saline soil (EC 20 dS m−1) amended with biochar (1% w/w). Results revealed that biochar and PsJN particularly when applied together significantly enhanced plant growth, grain yield, and grain nutrient contents of quinoa. Strikingly, iron concentration in quinoa grains was increased up to 71% by the combined application of biochar and PsJN. Moreover, plant physiological parameters were also improved significantly by the integrated application. However, enzymatic/non-enzymatic antioxidants activities were decreased by integrated treatment thus ameliorated salinity stress. Our study suggests that integrated application of siderophore-producing bacteria and biochar could be a promising, sustainable and cost-effective strategy which is easily integratable into the existing farming practices to achieve food fortification with micronutrients in developing countries.

Acid treated biochar enhances cadmium tolerance by restricting its uptake and improving physio-chemical attributes in quinoa (Chenopodium quinoa Willd.).

Heavy metals contamination of soil especially with cadmium (Cd) is a serious environmental concern in the current industrial era. Biochar serves as an excellent ameliorating agent depending upon its properties and application rates. In the pot scale study, effect of acid treated (AWSB) and untreated wheat straw biochar (WSB) was studied on physiology, grain yield, Cd accumulation, and tolerance of quinoa with possible health risks. Different levels of Cd (0, 25, 50 and 75mgkg-1), AWSB and WSB (1% and 2% (w/w)) were applied in soil. Accumulation of Cd in control plant tissues led to oxidative stress which was shown in terms of increased lipid peroxidation. While biochar application relieved the oxidative damage as confirmed by the low production of H2O2 and TBARS contents. Application of AWSB improved plant growth, pigment contents and gas exchange attributes by limiting the accumulation of Cd in root, shoot and grain of quinoa. Results revealed a significant improvement in the activity of superoxide (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) with biochar at elevated levels of Cd in soil. Target Hazard Quotient (THQ) remained<1 in the quinoa grains with WSB and AWSB under Cd stress. These results revealed that AWSB most effectively alleviated Cd toxicity in quinoa thereby decreasing Cd accumulation and regulation of Cd induced oxidative stress triggered by the antioxidant enzymatic system.

Understanding the chemical foundation and genetic mechanism of the black grain trait in quinoa by integrating metabolome and transcriptome analyses

Quinoa (Chenopodium quinoa Willd.) cultivars that produce black grains are thought to be more nutritious and contain powerful antioxidant properties, but little is known about the chemical foundation and the genetic mechanism behind this trait. In this research, widely-targeted metabolome and transcriptome analyses were employed to unveil the chemical and genetic differences between black and white quinoa cultivars. A total of 157 differentially expressed metabolites were found in the black and white quinoa cultivars. The tannins and flavonoids were present at high levels in the black quinoa grains. The tannins comprised 13 proanthocyanins, all of which could barely be detected in white grains. Proanthocyanidins are suggested to cause the black grain trait in Arabidopsis thaliana and Brassica species and are thought to produce the black grain trait, while contributing to antioxidant activity, in black grain quinoa. A total of 4620 differentially expressed unigenes were identified in the black and white quinoa grains. Structural genes associated with proanthocyanin biosynthesis, particularly DFR, LAR, LDOX and ANR, were more highly expressed in black than white grains. Genes involved in the betalain biosynthetic pathway, which competes with anthocyanin biosynthesis, showed relatively lower levels of expression in black grains. Two MYB and one MYC transcription factor related to the phenylpropane metabolic pathway displayed higher expression levels in black grains, while BvMYB1, associated with betalain biosynthesis, was not detected. This study suggested that the accumulation of proanthocyanins produces the black grain trait in quinoa, and the activation of transcription factors triggers the proanthocyanidin biosynthesis pathway.

Light Emission in Betalains: From Fluorescent Flowers to Biotechnological Applications.

The discovery of visible fluorescence in the plant pigments betalains revealed the existence of fluorescent patterns in flowers of plants of the order Caryophyllales, where betalains substitute anthocyanins. The serendipitous initial discovery led to a systemized characterization of the role of different substructures on the photophysical phenomenon. Strong fluorescence is general to all members of the family of betaxanthins linked to the structural property that the betalamic acid moiety is connected to an amine group. This property has led to bioinspired tailor-made probes and to the development of novel biotechnological applications in screening techniques or microscopy labeling. Here, we comprehensively review the photophysics, photochemistry, and photobiology of betalain fluorescence and describe all current applications.