Molecular hydrogen (H2) was first produced in the early 16th century, and hydrogen was formally identified as an element by Cavendish in 1766. The effects of H2 on biological systems were relatively quickly studied by several people including Priestley, Lavoisier, Cavallo and Davy (). Although such research has been sporadic over the last two hundred years (), there is now a growing realisation that treatment with hydrogen gas can have significant beneficial effects. This is particularly true in the biomedical arena where it has been mooted as a therapy for a range of medical conditions (; ), including cancer () and neurological disorders (). Of relevance here, such work shows that H2 is not toxic and well tolerated by humans.
The action of H2 in cells involves the reduction of reactive compounds such as hydroxyl radicals () and an increase in antioxidant capacity, both of which lead to reduced oxidative stress (), as well as other potential mechanisms (). Therefore, it is not surprising that similar mechanisms take place in plant cells. H2 has been shown to have favourable effects on seed germination (), plant growth () and stress tolerance, such as drought (). H2 can also be used to prolong the vase life of flowers () and for postharvest storage of fruits (; ) and vegetables (). Many of the studies using H2 treatments on plants focus on growth under stress conditions, which in many ways parallels findings observed in animals. Therefore, a Research Topic exploring the potential benefits of H2 in plant and food science is both timely and relevant.
This Research Topic attracted four articles. One of the issues when researchers are reporting their data is that they do not measure H2 concentrations in solution. This is important if standardised methodologies for treatment of plants and plant/food materials are ever going to be developed and adopted. One method which is sometimes used to estimate H2 concentrations is to measure the oxidation reduction potential (ORP) and using this to estimate the H2 concentration with the Nernst equation. The first paper in the SI by LeBaron and Sharpe demonstrated through in silico analysis that ORP is unreliable to estimate or compare H2 concentrations in aqueous solutions. The study suggested that more accurate methods should be employed, as small deviations in pH, temperature, and normal ORP fluctuations can significantly affect the predicted H2 concentrations, often exceeding the range used in most studies.
In an original research article, Dong et al. looked at the traditional Chinese herb Gastrodia elata, which is used for a range of remedies, including headaches, convulsions and epilepsy (). Their focus was on the effects of hydrogen-rich water (HRW) on the herb that had been freshly cut and was in 4°C storage. It was found that HRW decreased weight loss of material, and reduced the generation of reactive oxygen species (ROS), whilst increasing antioxidant activity. The lowering of activities of key metabolic enzymes such as cytochrome oxidase, succinate dehydrogenase and H+-ATPase was also noted. Overall, the use of HRW was beneficial during the storage of this herb.
Alwazeer et al. looked at the use of H2 in the extraction of phytochemicals from plant materials. They infused H2 into various solvents (water, ethanol, methanol) before their use in extraction from lemon peels. Compounds such as phenolics, flavonoids, and anthocyanins were extracted using solvents with and without H2. The addition of H2 into all the solvents significantly improved the extraction of all phytochemical groups studied with the highest levels found for H2-rich methanol. It was therefore concluded that addition of H2 to such processes was worth considering, which is supported by similar studies (for example, ; ; ; ; ).
Finally, a paper by Alwazeer et al. featuring several members of the editorial team, provides a comprehensive review of the Research Topic’s focus. This review covers the application of H2 in agricultural practices, food safety, processing and packaging, and the valorisation of food waste. It further explores the bioactivity of H2, along with the regulations, toxicity, and safety considerations associated with its use. The review concludes with a section on the current status of research and future perspectives for the use of H2 in plant growth, food science, and production practices. It is hoped that this will inspire further research endeavours in this area.
Considering the final paper in the SI, it is evident that this topic has a bright future. The application of H2 to plants at a variety of stages is relatively easy and cheap. Often treatments involving the creation of a HRW which can be used as a watering medium or sprayed onto plant materials, as well as a washing material for treating various foods. In enclosed spaces, H2 can be used directly as a gas, and both methods leave no toxic byproducts. H2 has been used safely in deep sea diving for approximately 80 years (). As H2 gas becomes used more, for example, in transport (), it is expected to become cheaper and more accessible, enhancing its cost-benefit profile. The potential applications of H₂ across various plant developmental stages and stress conditions offer significant promise for improving food security, plant physiology, crop yields, and food storage and processing.
Statements
Author contributions
DA: Writing–original draft, Writing–review and editing. LL: Writing–original draft, Writing–review and editing. AS: Writing–original draft, Writing–review and editing. TL: Writing–original draft, Writing–review and editing. JH: Writing–original draft, Writing–review and editing. YW: Writing–original draft, Writing–review and editing.
Funding
The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.
Acknowledgments
JH and AS would like to thank UWE, Bristol for support.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
1
AliM.BatoolS.KhalidN.AliS.RazaM. A.LiX.et al (2023). Recent trends in hydrogen-associated treatments for maintaining the postharvest quality of fresh and fresh-cut fruits and vegetables: a review. Food control.156, 110114. 10.1016/j.foodcont.2023.110114
2
AlwazeerD.ElnasanelkasimM. A. (2023). Hydrogen-rich water as a green solvent for the extraction of phytochemicals from agri-food wastes. Sustain. Chem. Pharm.33, 101035. 10.1016/j.scp.2023.101035
3
AlwazeerD.ElnasanelkasimM. A.ÇiğdemA.KanmazH.HayalogluA. A.HancockJ. T.et al (2023b). Hydrogen incorporation into solvents can improve the extraction of phenolics, flavonoids, anthocyanins, and antioxidants: a case-study using red beetroot. Industrial Crops Prod.202, 117005. 10.1016/j.indcrop.2023.117005
4
AlwazeerD.ElnasanelkasimM. A.Çi̇çekS.EnginT.ÇiğdemA.KaraoğulE. (2023a). Comparative study of phytochemical extraction using hydrogen-rich water and supercritical fluid extraction methods. Process Biochem.128, 218–226. 10.1016/j.procbio.2023.01.022
5
AlwazeerD.ElnasanelkasimM. A.EnginT.ÇiğdemA. (2023c). Use of hydrogen-rich water as a green solvent for the extraction of phytochemicals: case of olive leaves. J. Appl. Res. Med. Aromatic Plants35, 100472. 10.1016/j.jarmap.2023.100472
6
AlwazeerD.ÖzkanN. (2022). Incorporation of hydrogen into the packaging atmosphere protects the nutritional, textural and sensorial freshness notes of strawberries and extends shelf life. J. Food Sci. Technol.59, 3951–3964. 10.1007/s13197-022-05427-y
7
BjurstedtH.SeverinG. (1948). The prevention of decompression sickness and nitrogen narcosis by the use of hydrogen as a substitute for nitrogen, the Arne Zetterstrom method for deep-sea diving. Mil. Surg.103, 107–116. 10.1093/milmed/103.2.107
8
CeylanM. M.SilganM.ElnasanelkasimM. A.AlwazeerD. (2023). Impact of washing crude olive pomace oil with hydrogen-rich water and incorporating hydrogen into extraction solvents on quality attributes and phytochemical content of oil. J. Food Meas. Charact.17, 2029–2040. 10.1007/s11694-022-01801-8
9
GeL.YangM.YangN. N.YinX. X.SongW. G. (2017). Molecular hydrogen: a preventive and therapeutic medical gas for various diseases. Oncotarget8, 102653–102673. 10.18632/oncotarget.21130
10
HancockJ. T.LeBaronT. W. (2023). The early history of hydrogen and other gases in respiration and biological systems: revisiting Beddoes, Cavallo, and Davy. Oxygen3, 102–119. 10.3390/oxygen3010008
11
HancockJ. T.RussellG.CraigT. J.MayJ.MorseH. R.StamlerJ. S. (2022). Understanding hydrogen: lessons to be learned from physical interactions between the inert gases and the globin superfamily. Oxygen2, 578–590. 10.3390/oxygen2040038
12
HuH.LiP.WangY.GuR. (2014). Hydrogen-rich water delays postharvest ripening and senescence of kiwifruit. Food Chem.156, 100–109. 10.1016/j.foodchem.2014.01.067
13
IslamM. A.ShornaM. N. A.IslamS.BiswasS.BiswasJ.IslamS.et al (2023). Hydrogen-rich water: a key player in boosting wheat (Triticum aestivum L.) seedling growth and drought resilience. Sci. Rep.13, 22521. 10.1038/s41598-023-49973-7
14
LeBaronT. W.KuraB.KalocayovaB.TribulovaN.SlezakJ. (2019). A new approach for the prevention and treatment of cardiovascular disorders. Molecular hydrogen significantly reduces the effects of oxidative stress. Molecules24, 2076. 10.3390/molecules24112076
15
LeBaronT. W.OhnoK.HancockJ. T. (2023). The on/off history of hydrogen in medicine: will the interest persist this time around?Oxygen3, 143–162. 10.3390/oxygen3010011
16
NoorM. N. Z. M.AlauddinA. S.WongY. H.LooiC. Y.WongE. H.MadhavanP.et al (2023). A systematic review of molecular hydrogen therapy in cancer management. Asian Pac. J. Cancer Prev. APJCP24, 37–47. 10.31557/APJCP.2023.24.1.37
17
OhsawaI.IshikawaM.TakahashiK.WatanabeM.NishimakiK.YamagataK.et al (2007). Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nat. Med.13, 688–694. 10.1038/nm1577
18
OhtaS. (2014). Molecular hydrogen as a preventive and therapeutic medical gas: initiation, development and potential of hydrogen medicine. Pharmacol. & Ther.144, 1–11. 10.1016/j.pharmthera.2014.04.006
19
RamanathanD.HuangL.WilsonT.BolingW. (2023). Molecular hydrogen therapy for neurological diseases: a review of current evidence. Med. Gas Res.13, 94–98. 10.4103/2045-9912.359677
20
RenP. J.JinX.LiaoW. B.WangM.NiuL. J.LiX. P.et al (2017). Effect of hydrogen-rich water on vase life and quality in cut lily and rose flowers. Hortic. Environ. Biotechnol.58, 576–584. 10.1007/s13580-017-0043-2
21
SinghS.JainS.VenkateswaranP. S.TiwariA. K.NouniM. R.PandeyJ. K.et al (2015). Hydrogen: a sustainable fuel for future of the transport sector. Renew. Sustain. Energy Rev.51, 623–633. 10.1016/j.rser.2015.06.040
22
WuQ.SuN.HuangX.LingX.YuM.CuiJ.et al (2020). Hydrogen-rich water promotes elongation of hypocotyls and roots in plants through mediating the level of endogenous gibberellin and auxin. Funct. Plant Biol.47, 771–778. 10.1071/FP19107
23
WuY. N.WenS. H.ZhangW.YuS. S.YangK.LiuD.et al (2023). Gastrodia elata BI.: a comprehensive review of its traditional use, botany, phytochemistry, pharmacology, and pharmacokinetics. Evidence‐Based Complementary Altern. Med.2023, 5606021. 10.1155/2023/5606021
24
XuS.ZhuS.JiangY.WangN.WangR.ShenW.et al (2013). Hydrogen-rich water alleviates salt stress in rice during seed germination. Plant Soil370, 47–57. 10.1007/s11104-013-1614-3
Summary
Keywords
crops, food processing, hydrogen-rich water, molecular hydrogen, plant growth, post harvest, food security, sustainable technology
Citation
Alwazeer D, Li L, Stratakos AC, LeBaron TW, Hancock JT and Waché Y (2024) Editorial: Recent knowledge on the applications of molecular hydrogen in plant physiology, crop production, and food processing. Front. Food. Sci. Technol. 4:1501046. doi: 10.3389/frfst.2024.1501046
Received
24 September 2024
Accepted
30 September 2024
Published
11 October 2024
Volume
4 - 2024
Edited and reviewed by
Tatiana Koutchma, Agriculture and Agri-Food Canada (AAFC), Canada
Updates
Copyright
© 2024 Alwazeer, Li, Stratakos, LeBaron, Hancock and Waché.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: John T. Hancock, john.hancock@uwe.ac.uk
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.