Effect of microwave radiation on antioxidant capacities of Tartary buckwheat sprouts

Unraveling the binding mechanisms of transglutaminase and substrate subjected to microwaves: Molecular docking and molecular dynamic simulations

Previous studies showed that transglutaminase (TGase) and microwaves acted synergistically to improve the functional properties of proteins. The mechanism behind this has yet to be elucidated. In this study, the phenomenon of microwaves enhancing TGase activity was experimentally validated. Molecular docking and molecular dynamics simulations revealed that moderate microwaves (105 and 108 V/m) increased the structural flexibility of TGase and promoted the orientation of the side chain carboxylate anion group on Asp255, driving the reaction forward. Also, TGase underwent partial transformation from α-helix to turns or coils at 105 and 108 V/m, exposing more residues in the active site and facilitating the binding of the substrate (CBZ-Gln-Gly) to TGase. However, 109 V/m microwaves completely destroyed the TGase structure, inactivating the enzyme. This study provides insights into the molecular mechanisms underlying the interactions between TGase and substrate subjected to microwaves, promoting the future applications of TGase and microwaves in food processing.

Recent developments in applications of physical fields for microbial decontamination and enhancing nutritional properties of germinated edible seeds and sprouts: a review

Germinated edible seeds and sprouts have attracted consumers because of their nutritional values and health benefits. To ensure the microbial safety of the seed and sprout, emerging processing methods involving physical fields (PFs), having the characteristics of high efficiency and environmental safety, are increasingly proposed as effective decontamination processing technologies. This review summarizes recent progress on the application of PFs to germinating edible seeds, including their impact on microbial decontamination and nutritional quality and the associated influencing mechanisms in germination. The effectiveness, application scope, and limitation of the various physical techniques, including ultrasound, microwave, radio frequency, infrared heating, irradiation, pulsed light, plasma, and high-pressure processing, are symmetrically reviewed. Good application potential for improving seed germination and sprout growth is also described for promoting the accumulation of bioactive compounds in sprouts, and subsequently enhancing the antioxidant capacity under favorable PFs processing conditions. Moreover, the challenges and future directions of PFs in the application to germinated edible seeds are finally proposed. This review also attempts to provide an in-depth understanding of the effects of PFs on microbial safety and changes in nutritional properties of germinating edible seeds and a theoretical reference for the future development of PFs in processing safe sprouted seeds.

A review: The nutrition components, active substances and flavonoid accumulation of Tartary buckwheat sprouts and innovative physical technology for seeds germinating

Compared with the common grain, Tartary buckwheat enjoys higher nutritional value. Some distinctive nutrition associated with physiological activity of Tartary buckwheat is valuable in medicine. In addition, it's a good feed crop. In the paper, the main components (starch, protein, amino acid, fatty acid and mineral) and polyphenol bioactive components in Tartary buckwheat and its sprouts were reviewed, and the accumulation of flavonoids in sprouts during germination, especially the methods, synthetic pathways and mechanisms of flavonoid accumulation was summarized. The research on bioactive components and health benefits of Tartary buckwheat also were reviewed. Besides, the applications of innovative physical technology including microwave, magnetic, electromagnetic, ultrasonic, and light were also mentioned and highlighted, which could promote the enrichment of some active substances during seeds germination and growth of Tartary buckwheat sprouts. It would give a good support and benefit for the research and processing of Tartary buckwheat and its sprouts in next day.

Identification of Tartary Buckwheat (Fagopyrum tataricum (L.) Gaertn) and Common Buckwheat (Fagopyrum esculentum Moench) Using Gas Chromatography-Mass Spectroscopy-Based Untargeted Metabolomics

Tartary buckwheat has attracted more attention than common buckwheat due to its unique chemical composition and higher efficacy in the prevention of various diseases. The content of flavonoids in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) is higher than that in common buckwheat (Fagopyrum esculentum Moench). However, the processing process of Tartary buckwheat is complex, and the cost is high, which leads to the frequent phenomenon of common buckwheat counterfeiting and adulteration in Tartary buckwheat, which seriously damages the interests of consumers and disrupts the market order. In order to explore a new and simple identification method for Tartary buckwheat and common buckwheat, this article uses metabolomics technology based on GC-MS to identify Tartary buckwheat and common buckwheat. The results show that the PLS-DA model can identify Tartary buckwheat and common buckwheat, as well as Tartary buckwheat from different regions, without an over-fitting phenomenon. It was also found that ascorbate and aldarate metabolism was the main differential metabolic pathway between Tartary buckwheat and common buckwheat, as well as the amino acids biosynthesis pathway. This study provides a new attempt for the identification of Tartary buckwheat and common buckwheat for the quality control of related agricultural products.

Study on morphological traits, nutrient compositions and comparative metabolomics of diploid and tetraploid Tartary buckwheat sprouts during sprouting

Tartary buckwheat (TB) sprout is a kind of novel nutritional vegetable, but its consumption was limited by low biomass and thin hypocotyl. The tetraploid TB sprouts was considered to be able to solve this issue. However, the nutritional quality of tetraploid TB sprouts and differences between conventional (diploid) and tetraploid TB sprouts remain unclear. In this study, the morphological traits, nutrient compositions and metabolome changes of diploid and tetraploid TB sprouts were analyzed. The water, pigments and minerals contents of TB sprouts increased during sprouting, while the contents of total soluble protein, reducing sugar, cellulose, and total phenol decreased. Compared with diploid sprouts, tetraploid sprouts had higher biomass and thicker hypocotyl. Tetraploid sprouts had higher ash and carotenoid contents, but had lower phenol and flavonoid accumulation. 677 metabolites were identified in TB sprouts by UPLC-MS analysis, including 62 diseases-resistance metabolites and 43 key active ingredients. Some key bioactive metabolites, such as rimonabant, quinapril, 1-deoxynojirimycin and miglitol, were identified. 562 differential expressed metabolites (DEMs) were identified during sprouting with seven accumulation patterns, and five hormones were found to be involved in sprout development. Additionally, 209 DEMs between diploid and tetraploid sprouts were found, and some key bioactive metabolites were induced by chromosome doubling such as mesoridazine, amaralin, atractyloside A, rhamnetin and Qing Hau Sau. This work lays a basis for the development and utilization of TB sprouts and provides evidence for the selection of tetraploid varieties to produce sprouts with high biomass and quality.

The Alleviation of Metal Stress Nuisance for Plants—A Review of Promising Solutions in the Face of Environmental Challenges

Environmental changes are inevitable with time, but their intensification and diversification, occurring in the last several decades due to the combination of both natural and human-made causes, are really a matter of great apprehension. As a consequence, plants are exposed to a variety of abiotic stressors that contribute to their morpho-physiological, biochemical, and molecular alterations, which affects plant growth and development as well as the quality and productivity of crops. Thus, novel strategies are still being developed to meet the challenges of the modern world related to climate changes and natural ecosystem degradation. Innovative methods that have recently received special attention include eco-friendly, easily available, inexpensive, and, very often, plant-based methods. However, such approaches require better cognition and understanding of plant adaptations and acclimation mechanisms in response to adverse conditions. In this succinct review, we have highlighted defense mechanisms against external stimuli (mainly exposure to elevated levels of metal elements) which can be activated through permanent microevolutionary changes in metal-tolerant species or through exogenously applied priming agents that may ensure plant acclimation and thereby elevated stress resistance.

Effects of Microwave Treatment on Structure, Functional Properties and Antioxidant Activities of Germinated Tartary Buckwheat Protein

Tartary buckwheat protein (TBP) has promise as a potential source of novel natural nutrient plant protein ingredients. The modulating effects of microwave pretreatment at varying powers and times on the structure, functional properties, and antioxidant activities of germinated TBP were investigated. Compared with native germinated TBP, after microwave pretreatment, the content of free sulfhydryl groups in the germinated TBP increased, and the secondary structure changes showed a significant decrease in α-helix and an increase in random coil contents, and the intensity of the ultraviolet absorption peak increased (p < 0.05). In addition, microwave pretreatment significantly improved the solubility (24.37%), water-holding capacity (38.95%), emulsifying activity index (17.21%), emulsifying stability index (11.22%), foaming capacity (71.43%), and foaming stability (33.60%) of germinated TBP (p < 0.05), and the in vitro protein digestibility (5.56%) and antioxidant activities (DPPH (32.35%), ABTS (41.95%), and FRAP (41.46%)) of germinated TBP have also been improved. Among different treatment levels, a microwave level of 300 W/50 s gave the best results for the studied parameters. Specifically, microwave pretreatment could be a promising approach for modulating other germinated plant protein resources, as well as expanding the application of TBP.

Seed priming with non-ionizing physical agents: plant responses and underlying physiological mechanisms

Seed priming has long been explored as an effective value-added potential technique that results in improved germination, reduced seedling emergence time, shortened crop duration, increased stress tolerance and eventually increased higher grain production. However, the wider applicability of water or chemical-based conventional methods of seed priming is often restricted considering its deleterious effects on post-treatment storability or agricultural pollution due to the persistence of chemicals in plant systems or in the environment. In this context, the utilization of physical methods of seed priming for enhancing plant productivity has created a new horizon in the domain of seed technology. Being eco-friendly and cost-effective approaches, priming with extra-terrestrial or physical agents such as ionizing radiation such as X-rays and gamma rays and non-ionizing radiation such as ultrasonic wave, magnetic field, microwaves, and infrared light offers many advantages along with ensuring enhanced production over conventional methods. Ultraviolet radiations, bridging between ionizing and non-ionizing radiation, are important electromagnetic waves that would also be an effective priming agent. Non-ionizing radiation has certain biological advantages over ionizing radiation since it does not generate charged ions while passing through a subject, but has enough energy to cause biological effects. Extensive research works to study the effects of various non-ionizing physical priming methods are required before their wider exploitation in agriculture. With this background, this review aims to highlight the current understanding of non-ionizing physical methods of seed priming and its applicability to combat present-day challenges to achieve agro-ecological resilience.

Pretreatment with H2O2 Alleviates the Negative Impacts of NaCl Stress on Seed Germination of Tartary Buckwheat (Fagopyrum tataricum)

Soil salinization is one of the main abiotic stress factors impacting the growth of crops and the agricultural industry today. Thus, we aimed to investigate the effects of H₂O₂ pretreatment on seed germination in Tartary buckwheat (Fagopyrum tataricum) seeds under salt stress and to evaluate this species’ salt tolerance. Through the preliminary experiment, this study used 50 mmol L⁻¹ NaCl solution to induce seed stress. After soaking for 12 h in different H₂O₂ concentrations, seeds were laid in Petri dishes with 50 mmol L⁻¹ NaCl for seven days and the germination parameters and physiological indicators were measured to screen the optimal H₂O₂ pretreatment concentration and the salt tolerance index. Our results indicated that pretreatment with 5–10 mmol L⁻¹ H₂O₂ was most effective in alleviating NaCl’s impacts on the seeds’ germination parameters. Furthermore, the growth and material accumulation of seedlings was promoted; catalase, superoxide dismutase activity, and proline content were enhanced; and malondialdehyde content was reduced. Principal component analysis and stepwise regression revealed six key indicators that had a significant impact on the salt tolerance characteristics of F. tataricum, namely, germination potential, shoot fresh weight, root surface area, root average diameter, catalase activity, and superoxide dismutase activity.