Amylolytic activities and starch reserve mobilization during the germination of quinoa

Influence of salinity, germination, malting and fermentation on quinoa nutritional and bioactive profile

The depletion of freshwater resources, as well as climate change and population growth, are threatening the livelihoods of thousands of people around the world. The introduction of underutilized crops such as quinoa may be important in countries with limited productivity and/or limited access to water due to its resistance to different abiotic stresses and its high nutritional value. The aim of this review is to assess whether techniques such as germination, malting and fermentation would improve the nutritional and bioactive profile of quinoa. The use of nitrogen oxide-donating, oxygen-reactive and calcium-source substances increases germination. The ecotype used, temperature, humidity and germination time are determining factors in germination. The presence of lactic acid bacteria of the rust-type phenotype can improve the volume and texture during baking of the doughs, increase the fiber content and act as a prebiotic. These techniques produce a significant increase in the content of proteins, amino acids and bioactive compounds, as well as a decrease in anti-nutritional compounds. Further studies are needed to determine which conditions are the most suitable to achieve the best nutritional, functional, technological, and organoleptic quinoa properties.

Effect of magnetic field pretreatment on germination characteristics, phenolic biosynthesis, and antioxidant capacity of quinoa

The development of quinoa-based functional foods with cost-effective methods has gained considerable attention. In this study, the effects of magnetic field pretreatment on the germination characteristics, phenolic synthesis, and antioxidant system of quinoa (Chenopodium quinoa Willd.) were investigated. The results showed that the parameters of magnetic field pretreatment had different effects on the germination properties of five quinoa varieties, in which Sanjiang-1 (SJ-1) was more sensitive to magnetic field pretreatment. The content of total phenolics and phenolic acids in 24-h germinated seeds increased by 20.48% and 26.54%, respectively, under the pretreatment of 10 mT magnetic fields for 10 min compared with the control. This was closely related to the activation of the phenylpropanoid pathway by increasing enzyme activities and gene expression. In addition, magnetic field improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals scavenging capacities and increased peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione peroxidase (GSH-Px) activities. This study suggests that magnetic field pretreatment enhanced gene expression of phenylalanine ammonia lyase (PAL), 4-coumarate-CoA ligase (4CL), chalcone synthase (CHS) and chalcone isomerase (CHI), increased antioxidant enzyme activity and phenolics content. Thereby lead to an increase in the antioxidative capacity of quinoa.

Impact of Sprouting Process on the Protein Quality of Yellow and Red Quinoa (Chenopodium quinoa)

The demand for plant-based proteins has increased remarkably over the last decade. Expanding the availability and variety of plant-based protein options has shown positive potential. This study aimed to investigate the qualitative and quantitative changes in amino acids of yellow and red quinoa seeds (YQ and RQ) during a 9-day germination period. The results showed that the germination process led to an increase in the total amino acids by 7.43% and 14.36% in the YQ and RQ, respectively. Both varieties exhibited significant (p < 0.05) increases in non-essential and essential amino acids, including lysine, phenylalanine, threonine, and tyrosine. The content of non-essential amino acids nearly reached the standard values found in chicken eggs. These results were likely attributed to the impact of the germination process in increasing enzymes activity and decreasing anti-nutrient content (e.g., saponins). A linear relationship between increased seeds' hydration and decreased saponins content was observed, indicating the effect of water absorption in changing the chemical composition of the plant. Both sprouts showed positive germination progression; however, the sprouted RQ showed a higher germination rate than the YQ (57.67% vs. 43.33%, respectively). Overall, this study demonstrates that germination is a promising technique for enhancing the nutritional value of quinoa seeds, delivering sprouted quinoa seeds as a highly recommended source of high-protein grains with notable functional properties.

Regulatory function of the endogenous hormone in the germination process of quinoa seeds

The economic and health significance of quinoa is steadily growing on a global scale. Nevertheless, the primary obstacle to achieving high yields in quinoa cultivation is pre-harvest sprouting (PHS), which is intricately linked to seed dormancy. However, there exists a dearth of research concerning the regulatory mechanisms governing PHS. The regulation of seed germination by various plant hormones has been extensively studied. Consequently, understanding the mechanisms underlying the role of endogenous hormones in the germination process of quinoa seeds and developing strategies to mitigate PHS in quinoa cultivation are of significant research importance. This study employed the HPLC-ESI-MS/MS internal standard and ELISA method to quantify 8 endogenous hormones. The investigation of gene expression changes before and after germination was conducted using RNA-seq analysis, leading to the discovery of 280 differentially expressed genes associated with the regulatory pathway of endogenous hormones. Additionally, a correlation analysis of 99 genes with significant differences identified 14 potential genes that may act as crucial "transportation hubs" in hormonal interactions. Through the performance of an analysis on the modifications in hormone composition and the expression of associated regulatory genes, we posit a prediction that implies the presence of a negative feedback regulatory mechanism of endogenous hormones during the germination of quinoa seeds. This mechanism is potentially influenced by the unique structure of quinoa seeds. To shed light on the involvement of endogenous hormones in the process of quinoa seed germination, we have established a regulatory network. This study aims to offer innovative perspectives on the breeding of quinoa varieties that exhibit resistance to PHS, as well as strategies for preventing PHS.

Inter-Species Investigation of Biological Traits among Eight Echinochloa Species

Due to the diversity of Echinochloa species and the limited understanding of their damage processes in rice fields, clarifying the biological properties of distinct species could help create a foundation for effective control techniques. Pot experiments and field competition trials were conducted using eight Echinochloa species to elucidate their biological differences and assess their varying levels of negative impact on rice. The survey outcomes showed that E. oryzoides had the highest 1000-grain weight (3.12 g) while E. colona had the lowest (0.90 g). The largest grain number per spikelet found in E. glabrescens (940) was 3.4 times greater than that in E. oryzoides (277). Different species responded variably to changes in temperature and photoperiod. Except for E. caudate, all Echinochloa species exhibited a shortened growth period with the delay of the sowing date. Under field competitive conditions, all Echinochloa species exhibited significantly greater net photosynthetic rates than rice, with E. crusgalli exhibiting the highest photosynthetic capacity. Moreover, in this resource-limited setting, barnyardgrass species had a decrease in tiller formation and panicle initiation but a significant increase in plant height. These findings contribute valuable insights into the biological characteristics of barnyardgrass populations and provide guidance for implementing effective control measures in rice fields.

Characterization of the aroma profile of quinoa (Chenopodium quinoa Willd.) and assessment of the impact of malting on the odor-active volatile composition

BACKGROUND

Quinoa (Chenopodium quinoa Willd.) is a gluten-free pseudocereal, rich in starch and high-quality proteins. It can be used as a cereal. Recently, a variety of nontraditional food products were developed; however, the sharp bitterness and the earthy aroma of unprocessed quinoa interfered with the acceptance of these products. Malting of cereals is known to improve their processing properties and enhance their sensory quality. To evaluate the acceptance and potential of quinoa malt as a raw material for beverage production, malt quality indicators (e.g., soluble protein) and the aroma profiles of different quinoa malts were compared.

RESULTS

Initial sensory assessment of quinoa in its native and malted state identified differences in their aroma profiles and revealed that pleasant nutty and caramel aromas were formed by malting. Subsequently, three complementary isolation techniques and gas chromatography-olfactometry/mass spectrometry (GC-O/MS) were used for volatile analysis. Instrumental analysis detected 34 and 62 odor-active regions in native quinoa and quinoa malt, respectively. In the second part, storage and the impact of three malting parameters on volatile formation were examined. By varying the malting parameters, seven additional odor-active malting byproducts were revealed.

CONCLUSION

Three naturally occurring methoxypyrazines were identified as important contributors to the characteristic quinoa aroma. In all fresh quinoa malts a similar number of volatile compounds was perceived but their intensity and composition varied. Higher germination temperature promoted the formation of lipid oxidation products. Fatty smelling compounds and carboxylic acids, formed during storage, were classified as aging indicators of quinoa malt. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Snapshot of four mature quinoa (Chenopodium quinoa) seeds: a shotgun proteomics analysis with emphasis on seed maturation, reserves and early germination

Chenopodium quinoa Willd. is a crop species domesticated over 5000 years ago. This species is highly diverse, with a geographical distribution that covers more than 5000 km from Colombia to Chile, going through a variety of edaphoclimatic conditions. Quinoa grains have great nutritional quality, raising interest at a worldwide level. In this work, by using shotgun proteomics and in silico analysis, we present an overview of mature quinoa seed proteins from a physiological context and considering the process of seed maturation and future seed germination. For this purpose, we selected grains from four contrasting quinoa cultivars (Amarilla de Maranganí, Chadmo, Sajama and Nariño) with different edaphoclimatic and geographical origins. The results give insight on the most important metabolic pathways for mature quinoa seeds including: starch synthesis, protein bodies and lipid bodies composition, reserves and their mobilization, redox homeostasis, and stress related proteins like heat-shock proteins (HSPs) and late embryogenesis abundant proteins (LEAs), as well as evidence for capped and uncapped mRNA translation. LEAs present in our analysis show a specific pattern of expression matching that of other species. Overall, this work presents a complete snapshot of quinoa seeds physiological context, providing a reference point for further studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01295-8.

Effect of Sprouting on Proteins and Starch in Quinoa (Chenopodium quinoa Willd.)

This study aims at understanding the relation among sprouting time (from 12 up to 72 h), changes in protein and starch components, and flour functionality in quinoa. Changes related to the activity of sprouting-related proteases were observed after 48 h of sprouting in all protein fractions. Progressive proteolysis resulted in relevant modification in the organization of quinoa storage proteins, with a concomitant increase in the availability of physiologically relevant metals such as copper and zinc. Changes in the protein profile upon sprouting resulted in improved foam stability, but in impaired foaming capacity. The increased levels of amylolytic enzymes upon sprouting also made starch less prompt to gelatinize upon heating. Consequently, starch re-association in a more ordered structure upon cooling was less effective, resulting in low setback viscosity. The nature and the intensity of these modifications suggest various possibilities as for using flour from sprouted quinoa as an ingredient in the formulation of baked products.