Triterpene saponins from debittered quinoa (Chenopodium quinoa) seeds

Twelve triterpene saponins have been isolated from the debittered seeds of quinoa (Chenopodium quinoa), and their structures were characterized on the basis of hydrolysis and spectral data, especially NMR evidence. Among them, three compounds, including 3-O-beta-D-glucuropyranosyl oleanolic acid (1), 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl hederagenin (2), and the new compound 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl-30-O-methyl spergulagenate 28-O-beta-D-glucopyranosyl ester (3), are identified for the first time from quinoa seeds. The other isolated saponins have been previously reported in quinoa.     

Isolation and Characterization of Atriplex hortensis and Sweet Chenopodium quinoa Starches

Starches from garden orach (Atriplex hortensis) and sweet quinoa (Chenopodium quinoa Willd. ‘Surumi’) seeds were isolated, examined for compositional characteristics, and compared with bitter quinoa (Cheno‐podium quinoa Willd.) starch. Garden orach and sweet quinoa seeds were similar in fat and ash contents, while garden orach seeds contained ≈10% more protein. Starches were isolated from seeds following a 12‐hr soak in dilute alkaline solution using a series of grinding, screening, centrifugation, and washing steps. Isolated starches viewed by scanning electron microscopy yielded angular, polygonal granules ≈1–2 μm in diameter. Starches displayed typical A‐type crystalline packing arrangements as determined by X‐ray powder diffractometry. Apparent amylose contents for garden orach (21.2%), sweet quinoa (20.6%), and bitter quinoa (19.8%) were determined according to colorimetric procedure. Differential scanning calorimetry data indicated a higher and wider gelatinization temperature range for garden orach as compared with sweet and bitter quinoa starches. Starch pasting profiles generated using a Rapid Visco Analyser indicated a reduced peak paste viscosity for garden orach starch relative to sweet and bitter quinoa and common corn starches.     

不同粒色藜麦挤压面条品质特性分析

为了探究不同粒色藜麦挤压面条品质特性的差异及机理,该研究对比分析了不同粒色藜麦粉的基础组分、糊化特性、挤压面条微观结构、蒸煮品质、活性成分及淀粉体外消化特性的差异。结果表明：白藜麦粉中淀粉含量最高,糊化后峰值黏度、最终黏度和回生值也最高。红、黑藜麦粉及挤压面条中的多酚、黄酮含量及抗氧化活性显著高于白藜麦粉和挤压面条。挤压后,淀粉结晶度均下降,白藜麦面条中淀粉的结晶度最高。红（2.25 min）、黑藜麦（2.75 min）面条的蒸煮时间短,但蒸煮品质显著低于白藜麦面条（P < 0.05）。扫描电镜显示白藜麦面条淀粉凝胶网络结构更加连续致密,导致其淀粉水解率和预计升糖指数显著低于红、黑藜麦面条（P < 0.05）。该研究为高品质藜麦面条的生产加工提供理论和技术参考。     

Studies on the constituents of Chenopodium quinoa seeds: isolation and characterization of new triterpene saponins

Six triterpenoid saponins were isolated from the edible grain quinoa, which is seeds of Chenopodium quinoa (Chenopodiaceae). Following are their structures: phytolaccagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (1); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (2); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' "-->3' ')-beta-D-xylopyranosyl-(1' '-->2')-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (3); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1' "-->2' ')-beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (4); oleanolic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (5); and oleanolic acid 3-O-[beta-D-glucopyranosyl-(1' '-->3')-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (6). The oleanane-type saponins (5, 6) were isolated for the first time in this plant, two of the phytolaccagenane (1, 3) were new compounds and two (2, 4) were previously found in quinoa. The structures were characterized on the basis of hydrolysis and spectral evidence, including 1D- and 2-D NMR (HMQC and HMBC) and ESI-MS analyses.     

Simultaneous determination of phenolic compounds and saponins in quinoa (Chenopodium quinoa Willd) by a liquid chromatography-diode array detection-electrospray ionization-time-of-flight mass spectrometry methodology

A new liquid chromatography methodology coupled to a diode array detector and a time-of-flight mass spectrometer has been developed for the simultaneous determination of phenolic compounds and saponins in quinoa (Chenopodium quinoa Willd). This method has allowed the simultaneous determination of these two families of compounds with the same analytical method for the first time. A fused-core column C18 has been used, and the analysis has been performed in less than 27 min. Both chromatographic and electrospray ionization time-of-flight mass spectrometry parameters have been optimized to improve the sensitivity and to maximize the number of compounds detected. A validation of the method has also been carried out, and free and bound polar fractions of quinoa have been studied. Twenty-five compounds have been tentatively identified and quantified in the free polar fraction, while five compounds have been tentatively identified and quantified in the bound polar fraction. It is important to highlight that 1-O-galloyl-β-D-glucoside, acacetin, protocatechuic acid 4-O-glucoside, penstebioside, ethyl-m-digallate, (epi)-gallocatechin, and canthoside have been tentatively identified for the first time in quinoa. Free phenolic compounds have been found to be in the range of 2.746-3.803 g/kg of quinoa, while bound phenolic compounds were present in a concentration that varies from 0.139 and 0.164 g/kg. Indeed, saponins have been found to be in a concentration that ranged from 5.6 to 7.5% of the total composition of whole quinoa flour.     

Identification and biological activities of triterpenoid saponins from Chenopodium quinoa

At least 16 saponins were detected in the seeds of Chenopodium quinoa. The 5 previously isolated major saponins, 3-O-beta-D-glucuronopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-arabinopyranosyl hederagenin 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl hederagenin 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-arabinopyranosyl phytolaccagenic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl phytolaccagenic acid 28-O-beta-D-glucopyranosyl ester, and the new saponin 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl phytolaccagenic acid were isolated and characterized using mainly NMR spectroscopy, mass spectrometry, and chemical methods. The antifungal activity against Candida albicans and hemolytic activity on erythrocytes of these compounds and derived monodesmosides were evaluated. Both bidesmosides and derived monodesmosides showed little or no antifungal activity, whereas a comparatively higher degree of hemolytic activity could be determined for monodesmosides.     

New oleanane saponins in Chenopodium quinoa

Six triterpenoid saponins were isolated from the seeds of Chenopodium quinoa (Chenopodiaceae). Their structures were as follows: phytolaccagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (1); spergulagenic acid 3-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl-28-O-beta-D-glucopyranoside (2); hederagenin 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl]-28-O-beta-D-glucopyranoside (3); phytolaccagenic acid 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (4); hederagenin 3-O-[beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranosyl]-28-O-beta-D-glucopyranoside (5); and spergulagenic acid 3-O-[alpha-L-arabinopyranosyl-(1' '-->3')-beta-D-glucuronopyranosyl]-28-O-beta-D-glucopyranoside (6). Saponins 5 and 6 are new. The structures were characterized on the basis of hydrolysis and spectral evidence, including IR, UV, optical rotations, 1D- and 2D-NMR (HMQC and HMBC), ESIMS, and FABMS analyses.     

Immunoadjuvant activity, toxicity assays, and determination by UPLC/Q-TOF-MS of triterpenic saponins from Chenopodium quinoa seeds

The adjuvant activity of Chenopodium quinoa (quinoa) saponins on the humoral and cellular immune responses of mice subcutaneously immunized with ovalbumin (OVA) was evaluated. Two quinoa saponin fractions were obtained, FQ70 and FQ90, and 10 saponins were determined by UPLC/Q-TOF-MS. Mice were immunized subcutaneously with OVA alone or adjuvanted with Quil A (adjuvant control), FQ70, or FQ90. FQ70 and FQ90 significantly enhanced the amount of anti-OVA-specific antibodies in serum (IgG, IgG1, and IgG2b) in immunized mice. The adjuvant effect of FQ70 was significantly greater than that of FQ90. However, delayed type hypersensitivity responses were higher in mice immunized with OVA adjuvanted with FQ90 than mice treated with FQ70. Concanavalin A (Con A)-, lipopolysaccharide-, and OVA-stimulated splenocyte proliferation were measured, and FQ90 significantly enhanced the Con A-induced splenocyte proliferation. The results suggested that the two quinoa saponin fractions enhanced significantly the production of humoral and cellular immune responses to OVA in mice.     

基于岭脊分析的藜麦淀粉提取及糊化特性研究

为优化藜麦淀粉碱法提取工艺,以藜麦为试验材料,采用岭脊分析法研究料液比、NaOH 质量分数和浸提时间对淀粉提取率的影响,并对藜麦淀粉的颗粒形貌、化学结构及淀粉糊化特性进行研究。结果表明,碱法提取藜麦淀粉的优化工艺参数为料液比1：5 g/mL、NaOH质量分数0.2%和浸提时间5.5 h,淀粉提取率为98.94%±0.26%;藜麦淀粉为限制性膨胀淀粉,形态多呈不规则形,具有-OH、-CH2、-CHO、C-O-C和吡喃环典型淀粉分子官能团;随静置时间增加,淀粉透光率降低,凝沉体积增加,12 h后基本稳定;藜麦淀粉糊第四次冻融循环后达到稳定状态;对淀粉凝胶质构特性分析,硬度、内聚性、弹性、胶黏性和咀嚼性5个指标都随藜麦淀粉糊浓度增加而增大;流变性分析表明藜麦淀粉糊为假塑性流体,其弹性优于黏性。该文系统研究藜麦淀粉提取工艺和糊化特性,拓展了新的淀粉资源,同时也为藜麦淀粉的生产和应用提供一定的借鉴和参考。     

Study of some physicochemical and functional properties of quinoa (chenopodium quinoa willd) protein isolates

The amino acid composition and the physicochemical and functional properties of quinoa protein isolates were evaluated. Protein isolates were prepared from quinoa seed by alkaline solubilization (at pH 9, called Q9, and at pH 11, called Q11) followed by isoelectric precipitation and spray drying. Q9 and Q11 had high levels of essential amino acids, with high levels of lysine. Both isolates showed similar patterns in native/SDS-PAGE and SEM. The pH effect on fluorescence measurements showed decreasing fluorescence intensity and a shift in the maximum of emission of both isolates. Q9 showed an endotherm with a denaturation temperature of 98.1 degrees C and a denaturation enthalpy of 12.7 J/g, while Q11 showed no endotherm. The protein solubility of Q11 was lower than that of Q9 at pH above 5.0 but similar at the pH range 3.0-4.0. The water holding capacity (WHC) was similar in both isolates and was not affected by pH. The water imbibing capacity (WIC) was double for Q11 (3.5 mL of water/g isolate). Analysis of DSC, fluorescence, and solubility data suggests that there is apparently denaturation due to pH. Some differences were found that could be attributed to the extreme pH treatments in protein isolates and the nature of quinoa proteins. Q9 and Q11 can be used as a valuable source of nutrition for infants and children. Q9 may be used as an ingredient in nutritive beverages, and Q11 may be used as an ingredient in sauces, sausages, and soups.     

Photoperiodic effect on flowering and seed development in quinoa (Chenopodium quinoa Willd.)

Abstract

Sensitivity to photoperiod in quinoa (Chenopodium quinoa Willd.) was studied under controlled conditions to enhance crop adaptation to environments outside its centre of origin. Two varieties, a traditional variety from Bolivia (Real), which will not mature under Danish conditions, and an early maturing variety (Q52), developed for Danish climatic conditions, were used in this reciprocal transfer experiment. Plants were moved from a short daylength of 10 h (SD) to a long daylength of 18 h (LD) and vice versa at set intervals from sowing to 100 days after sowing (DAS). A reaction of LD in time to flowering was observed only in the Bolivian variety Real. Under SD both varieties flowered after 39 DAS. For Real the LD regime resulted in a moderate increase in time to flowering to 44 DAS. The non-sensitive, juvenile period in Real was estimated to be approximately 16 days. In Q52 a moderate increase in the number of leaves was formed on the main stem after flowering at LD, which indicates that some daylength sensitivity remains. The most striking difference occurred during seed filling, when going from SD to LD. In Q52 the time from the end of flowering to maturity increased from 39 to 52 days. Under SD, Real had a seed-filling period similar to Q52, but at LD Real remained with green leaves during seed filling. Hard seed was observed in the still green perigonium 57 days after end of flowering. At this moment re-shooting occurred from the inflorescence, and seed maturity was not reached at the termination of the experiment at 150 DAS. This study shows that flower induction is not a major problem for adaptation of quinoa to North European conditions but that a very strong, daylength sensitive, stay green reaction is the main cause of the late maturity of South American introductions.     

Genetic diversity of Colombian quinoa (Chenopodium quinoa Willd.): implications for breeding programs

Genetic Resources and Crop Evolution - Chenopodium quinoa Willd. is a species of great interest for global food security because of its ability to adapt to different environmental conditions and...     

Phenolic compounds and saponins in quinoa samples (Chenopodium quinoa Willd.) grown under different saline and nonsaline irrigation regimens

Quinoa is a pseudocereal from South America that has received increased interest around the world because it is a good source of different nutrients and rich in antioxidant compounds. Thus, this study has focused on the effects of different agronomic variables, such as irrigation and salinity, on the phenolic and saponin profiles of quinoa. It was observed that irrigation with 25% of full water restitution, with and without the addition of salt, was associated with increases in free phenolic compounds of 23.16 and 26.27%, respectively. In contrast, bound phenolic compounds were not affected by environmental stresses. Saponins decreased if samples were exposed to drought and saline regimens. In situations of severe water deficit, the saponins content decreased 45%, and 50% when a salt stress was added. The results suggest that irrigation and salinity may regulate the production of bioactive compounds in quinoa, influencing its nutritional and industrial values.     

Physicochemical and Functional Characterization of Protein Isolated from Different Quinoa Varieties (Chenopodium quinoa Willd.)

The objectives of this work were to investigate the nutritional and physicochemical characteristics as well as the functional properties of quinoa protein isolates (QPI) from different varieties, and to determine their potential use of such protein isolates in food products. Proteins were isolated by isoelectric precipitation at pH 5 from quinoa flour, and the QPI had a protein percentage of over 85%. The comparison of the flours and QPI electrophoretic profiles indicated that the extraction method allowed isolating practically all proteins of each variety. All the varieties analyzed had high lysine content, compared with cereals, and the essential amino acid content of Bolivian varieties was higher than varieties from Peru. The pH value affected the solubility and foaming capacity, and the magnitude of effects depended on the variety. Cluster analysis showed a strong influence of variety source and amino acid composition on protein physicochemical and functional properties; samples from Bolivia (cluster 2) were characterized as having the highest thermal stability, oil binding capacity, and water binding capacity at acid pH; samples from Peru (cluster 1) had the highest water binding capacity at basic pH and foaming capacity at pH 5. QPI presented a potential as an alternative vegetable protein for food application, in particular for vegetarian and vegan diets.     

A New Simple Method for the Evaluation of Mineral Elements in Different Oilseeds

A method for the analysis of seven mineral contents—that is, potassium (K), calcium (Ca), phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)—was investigated in some oilseeds like flax, sesame, pumpkin, quinoa, and yellow mustard. X-ray Spectral Analysis method with Spectrometer EDX-900HS was used for the analytical concentrations of the macro and micro elements of the oilseeds. A relatively high level of Zn content was found in sesame and pumpkin seeds, while the highest level of Fe content was found in mustard seeds. Regarding the macro elements (K, Ca, and P) content, the highest levels of concentration were found in flax and mustard seeds. The highest values of Cu were obtained in sesame seeds while those of Mn were in pumpkin and brown flax seeds. The results showed that the method is a reliable and simple analytical procedure to characterize mineral elements in oilseeds with a very high analytical performance.     

Fermentation of Colored Quinoa Seeds with Neurospora intermedia to Obtain Oncom‐Type Products of Favorable Nutritional and Bioactive Characteristics

In this research, colored quinoa seeds were subjected to a modified oncom‐type processing (precooking followed by solid‐state fermentation with Neurospora intermedia ) to obtain convenient food products of improved parameters. Compared with the raw material, the products contained a higher level of protein (on average by 44%, with an advantageous essential amino acid profile) and fiber (by 71%) but a lower amount of inositol phosphates (by 50%, with an increased share of InsP₃ fraction in the profile). Fermented quinoa was enriched in carotenoids (6.5‐fold) and riboflavin (fivefold). The antioxidant potential of oncom was also improved in respect to antiradical activity (on average by 39%) and reducing power. Of the red and black quinoa, the former substrate was processed into a product of better quality, containing a higher level of protein (214 g/kg dry matter [DM]), fiber (234 g/kg DM), carotenoids (81 mg/kg DM), and riboflavin (8 mg/kg DM), as well as antiradical activity (IC₅₀ in ABTS^⋅+ and DPPH^⋅ assay of 0.4 and 3 mg DM, respectively). This was associated with a 50% higher level of fungal glucosamine in this oncom. Therefore, the activity of N. intermedia can be considered beneficial for biotreatment of quinoa seeds.     

Variation of Seed Mineral Concentrations in Seven Quinoa Cultivars Grown in Two Agroecological Sites

Variations in concentration and tissue distribution of mineral elements in seeds of seven quinoa cultivars from both a “natural” habitat (Patacamaya, Bolivia, 3,960 m above sea level) and a “nonnatural” habitat (Encalilla, Argentina, 1,980 m above sea level) were analyzed. Data clearly showed inter‐ and intravarietal differences in seed mineral concentrations between the two sites. Correlation analysis revealed that concentrations of major and minor dietary minerals as well as essential ultratrace elements of Encalilla seeds showed, in general, higher correlations with both seed protein and seed yield than did element concentrations of Patacamaya seeds. Results of scanning electron microscopy combined with energy dispersive X‐ray spectroscopy showed clearly differences in the contents of major mineral elements (calcium, magnesium, potassium, phosphorus, and sulfur) in the pericarp and embryonic axis (cotyledon + radicle). Obtained data could indicate that genotype × environment interactions are responsible for mineral variations occurring in quinoa cultivars. Results can also be useful for developing mineral biofortification strategies for the world's poorest regions.     

Improving Strategic Growth Stage-based Drought Tolerance in Quinoa by Rhizobacterial Inoculation

ABSTRACT

Climate change is imposing high temperature resulting in prolonged drought episodes and shrinking of fresh water resources across the globe. In this scenario, even drought tolerant crops like quinoa are also losing significant yield. However, this study was planned to investigate the impact of drought on quinoa at critical growth stages and bacterial inoculation to improve drought tolerance. Drought was imposed by maintaining 25% pot water holding capacity (PWC) at multiple leaf, flowering, and seed filling stage (DSFS), while 80% PWC was considered as control. Three strains of plant growth promoting rhizobacteria (PGPR) named as: Bacillus licheniformis, Pseudomonas fluorescens, and Azospirillum brasilense were inoculated with quinoa seeds before sowing with respect to drought treatments. PGPR inoculation mitigated the drastic effects of drought by improving crop growth, net assimilation rate, water use efficiency, leaf chlorophyll, and phenolic contents, all of these ultimately contributed to improvement in grain yield and its contributing attributes. Moreover, PGPR markedly improves the grain quality attributes including protein, phosphorus, and potassium contents. Principal component analysis linked the different scales of study and demonstrated the potential of physio-biochemical traits to explain the quinoa yield variations under drought condition with response to PGPR inoculation. Among different PGPR, A. brasilense was found most effective both under normal and drought conditions. Overall, DSFS has more detrimental effects among critical growth stages of quinoa and A. brasilense can be used as a shotgun tactic to ameliorate drought stress in quinoa.