Synergistic Effect of Atmospheric Pressure Cold Plasma and Hydrogen Peroxide as an Efficient Approach for the Control of Citrus Postharvest Green Mold

Articles in Press

Document Type : Research Article

Authors

• E. Barzanouni ¹
• H. Sadrnia ²
• F. Sohbatzadeh ³
• S. Khodavaisy ⁴

¹ PhD Student, Department of Biosystems Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

² Department of Biosystems Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

³ Department of Atomic and Molecular Physics, Faculty of Science, University of Mazandaran, Babolsar, Iran

⁴ Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran & Research Center for Antibiotic Stewardship and Antimicrobial Resistance, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran

10.22067/jam.2023.82325.1165

Abstract

Introduction
Penicillium Digitatum (PD) and Penicillium italicum diseases pose significant economic challenges to citrus fruit production across the globe. The primary aim of this research is to investigate the synergistic effects of low concentrations of H₂O₂ solution combined with transient spark discharge plasma on the inactivation of PD. Additionally, assess the chemical and physical properties. Ultimately, this approach can be presented as an eco-friendly solution for rinsing citrus fruits on an industrial scale.
Materials and Methods
The Penicillium digitatum (PD) isolate (ATCC 24692) was obtained from the Tehran Molecular Mycology Laboratory and cultured on Sabouraud Dextrose Agar medium at pH 5.6 and 27°C for 7 days. The initial concentration of spores in the solution was determined using a UV absorption spectrophotometer, set to 0.1 at a wavelength of 420 nm, and the concentration of spores was approximately equivalent to 10⁶ spores per milliliter (Palou et al., 2002). In this study, the plasma reactor had a point-to-plane geometry. The high-voltage needle electrode was placed above a Petri dish filled with a microbial solution combined with H₂O₂, while the grounded electrode was immersed in the solution. The distance between the tip of the needle electrode and the surface of the solution was 15 mm. Solutions of 0.05%, 0.1% and 0.5%v/v H₂O₂ (35% soluble in water) were added to the microbial solution before plasma treatment. The final volume of the solution was 5 ml and exposure times were 2.5, 5, 10, and 15 minutes. The reactor was fed with an air flow of 2 l/min. A transient spark discharge was generated, characterized by a discharge voltage of approximately 18 kV, short durations of less than 100 ns, and high current pulses exceeding 1A, with a repetition frequency ranging from 0.5 to 10 kHz. After treatment, H₂O₂, NO₂‾, and NO₃‾ as the main long-lived species in plasma-activated solution are measured. Also, physical factors such as electrical conductivity and pH were measured. Data Analysis performed using SAS 9.4 software. 
Results and Discussion
With increasing plasma treatment time and H₂O₂ concentration, the log reduction increased across all treatments. The combination of 0.1 and 0.5% H₂O₂ solution with plasma resulted in complete inactivation of P. digitatum within just 15 minutes. In plasma-treated solutions, regarding chemical properties, the concentrations of H₂O₂, NO₂‾, and NO₃‾ increased linearly with the treatment time. Furthermore, the electrical conductivity increased linearly, with a notable acceleration in the treated 0.5% H₂O₂ solution, reaching 373µS cm^-1. Additionally, pH value dropped from an initial value of 6.95, using distilled water as a control, to a low of 2.14 for plasma treated with 0.5% H₂O₂ after 15 min of exposure.
Conclusion
The combined treatment was more effective than the isolated use of hydrogen peroxide solution. H₂O₂ enhances the effectiveness of plsma sterilization without requiring additional power input. Consequently, the synergistic application of atmospheric pressure plasma and H₂O₂ proved to be a promising method for the inactivation of PD. The findings indicate that reactive oxygen species (ROS) significantly contribute to the inactivation of PD cells, as well as the concentration of H₂O₂. Finally, the combination of H₂O₂ solution at 0.1 and 0.5% with cold plasma presents an environmentally friendly method for sanitizing citrus fruits.
Acknowledgment 
This work was supported by the Ferdowsi University of Mashhad [Grant number 48527]. The authors greatly appreciate the technical support from Mazandaran University in Iran, particularly from the Department of Atomic and Molecular Physics. 

Keywords

• Hydrogen peroxide
• Non-thermal plasma
• Penicillium digitatum
• Plasma-activated solution
• Transient spark discharge

Main Subjects

• Post-harvest technologies

©2024 The author(s). This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)

References

1. Bekeschus, S., Kolata, J., Winterbourn, C., Kramer, A., Turner, R., Weltmann, K., Bröker, B., & Masur, K. (2014). Hydrogen peroxide: A central player in physical plasma-induced oxidative stress in human blood cells. Free Radical Research, 48(5), 542-549. https://doi.org/10.3109/10715762.2014.892937
2. Bruggeman, P., & Schram, D. C. (2010). On OH production in water containing atmospheric pressure plasmas. Plasma Sources Science and Technology, 19(4). https://doi.org/10.1088/0963-0252/19/4/045025
3. Graves, D. B. (2012). The emerging role of reactive oxygen and nitrogen species in redox biology and some implications for plasma applications to medicine and biology. Journal of Physics D: Applied Physics, 45(26), 263001. https://doi.org/10.1088/0022-3727/45/26/263001
4. Hao, X., Mattson, A. M., Edelblute, C. M., Malik, M. A., Heller, L. C., & Kolb, J. F. (2014). Nitric oxide generation with an air operated non‐thermal plasma jet and associated microbial inactivation mechanisms. Plasma Processes and Polymers, 11(11), 1044-1056. https://doi.org/10.1002/ppap.201300187
5. Iseki, S., Hashizume, H., Jia, F., Takeda, K., Ishikawa, K., Ohta, T., Ito, M., & Hori, M. (2011). Inactivation of Penicillium digitatum spores by a high-density ground-state atomic oxygen-radical source employing an atmospheric-pressure plasma. Applied Physics Express, 4(11), 116201. https://doi.org/10.1143/APEX.4.116201
6. Ito, M., Oh, J. S., Ohta, T., Shiratani, M., & Hori, M. (2018). Current status and future prospects of agricultural applications using atmospheric‐pressure plasma technologies. Plasma Processes and Polymers, 15(2), 1700073. https://doi.org/10.1002/ppap.201700073
7. Ito, M., Ohta, T., & Hori, M. (2012). Plasma agriculture. Journal of the Korean Physical Society, 60, 937-943. https://doi.org/10.3938/jkps.60.937
8. Lee, H. W., Lee, H., Kang, S., Kim, H., Won, I., Jeon, S., & Lee, J. (2013). Synergistic sterilization effect of microwave-excited nonthermal Ar plasma, H₂O₂, H₂O and TiO₂, and a global modeling of the interactions. Plasma Sources Science and Technology, 22(5), 055.008. https://doi.org/10.1088/0963-0252/22/5/055008
9. Lee, K. N., Paek, K. H., Ju, W. T., & Lee, Y. H. (2006). Sterilization of bacteria, yeast, and bacterial endospores by atmospheric-pressure cold plasma using helium and oxygen. Journal of Microbiology, 44(3), 269-275.
10. Liu, F., Sun, P., Bai, N., Tian, Y., Zhou, H., Wei, S., Zhou, Y., Zhang, J., Zhu, W., & Becker, K. (2010). Inactivation of bacteria in an aqueous environment by a direct current, cold atmospheric pressure air plasma microjet. Plasma Processes and Polymers, 7(3-4), 231-236. https://doi.org/10.1002/ppap.200900070
11. Liu, K., Wang, C., Hu, H., Lei, J., & Han, L. (2016). Indirect treatment effects of water–air MHCD jet on the inactivation of Penicillium Digitatum suspension. IEEE Transactions on Plasma Science, 44(11), 2729-2737. https://doi.org/10.1109/TPS.2016.2608926
12. Liu, Z., Zhou, C., Liu, D., He, T., Guo, L., Xu, D., & Kong, M. G. (2019). Quantifying the concentration and penetration depth of long-lived RONS in plasma-activated water by UV absorption spectroscopy. AIP Advances, 9(1), 015014. https://doi.org/10.1063/1.5037660
13. Ma, R., Wang, G., Tian, Y., Wang, K., Zhang, J., & Fang, J. (2015). Non-thermal plasma-activated water inactivation of food-borne pathogen on fresh produce. Journal of Hazardous Materials, 300, 643-651. https://doi.org/10.1016/j.jhazmat.2015.07.061
14. Maeda, Y., Igura, N., Shimoda, M., & Hayakawa, I. (2003). Bactericidal effect of atmospheric gas plasma on Escherichia coli K12. International Journal of Food Science and Technology, 38(8), 889-892.
15. Merenyi, G., Lind, J., Naumov, S., & Sonntag, C. V. (2010). Reaction of ozone with hydrogen peroxide (peroxone process): a revision of current mechanistic concepts based on thermokinetic and quantum-chemical considerations. Environmental Science & Technology, 44(9), 3505-3507. https://doi.org/10.1021/es100277d
16. Misra, N., Kaur, S., Tiwari, B. K., Kaur, A., Singh, N., & Cullen, P. (2015). Atmospheric pressure cold plasma (ACP) treatment of wheat flour. Food Hydrocolloids, 44, 115-121. https://doi.org/10.1016/j.foodhyd.2014.08.019
17. Misra, N., Schlüter, O., & Cullen, P. (2016). Plasma in food and agriculture. In Cold plasma in food and agriculture (pp. 1-16). Elsevier. https://doi.org/10.1016/B978-0-12-801365-6.00001-9
18. Naïtali, M., Kamgang-Youbi, G., Herry, J. M., Bellon-Fontaine, M. N., & Brisset, J. L. (2010). Combined effects of long-living chemical species during microbial inactivation using atmospheric plasma-treated water. Applied and Environmental Microbiology, 76(22), 7662-7664. https://doi.org/10.1128/AEM.01615-10
19. NOP. (2003). National Organic Program, Federal Register
20. Ohta, T., Ito, M., Iseki, S., & Hori, M. (2010). Inactivation mechanism of Penicillium digitatum using atmospheric pressure plasma. TENCON 2010-2010 IEEE Region 10 Conference. https://doi.org/10.1109/TENCON.2010.5685967
21. Palou, L., Usall, J., Smilanick, J. L., Aguilar, M. J., & Vinas, I. (2002). Evaluation of food additives and low toxicity compounds as alternative chemicals for the control of Penicillium digitatum and Penicillium italicum on citrus fruit. Pest Management Science, 58(5), 459-466. https://doi.org/10.1002/ps.477
22. Parish, M., Beuchat, L., Suslow, T., Harris, L., Garrett, E., Farber, J., & Busta, F. (2003). Methods to reduce/eliminate pathogens from fresh and fresh cut produce. Comprehensive Reviews in Food Science and Food Safety, 2, 161-173. https://doi.org/10.1111/j.1541-4337.2003.tb00033.x
23. Park, G., Ryu, Y. H., Hong, Y. J., Choi, E. H., & Uhm, H. S. (2012). Cellular and molecular responses of Neurospora crassa to non-thermal plasma at atmospheric pressure. Applied Physics Letters, 100(6), 063703. https://doi.org/10.1063/1.3684632
24. Puligundla, P., Lee, T., & Mok, C. (2018). Effect of intermittent corona discharge plasma treatment for improving microbial quality and shelf life of kumquat (Citrus japonica) fruits. LWT, 91, 8-13. https://doi.org/10.1016/j.lwt.2018.01.019
25. Shen, J., Tian, Y., Li, Y., Ma, R., Zhang, Q., Zhang, J., & Fang, J. (2016). Bactericidal effects against S. aureus and physicochemical properties of plasma activated water stored at different temperatures. Scientific Reports, 6(1), 28505. https://doi.org/10.1038/srep28505
26. Smilanick, J., Brown, G., & Eckert, J. (2006). The biology and control of postharvest diseases. Fresh Citrus Fruits, 339-396.
27. Suslow, T. (1997). Postharvest Chlorination: Basic Properties & Key Points for Effective Distribution.
28. Timoshkin, I. V., Maclean, M., Wilson, M. P., Given, M. J., MacGregor, S. J., Wang, T., & Anderson, J. G. (2012). Bactericidal effect of corona discharges in atmospheric air. IEEE Transactions on Plasma Science, 40(10), 232. https://doi.org/10.1109/TPS.2012.2193621
29. Traylor, M. J., Pavlovich, M. J., Karim, S., Hait, P., Sakiyama, Y., Clark, D. S., & Graves, D. B. (2011). Long-term antibacterial efficacy of air plasma-activated water. Journal of Physics D: Applied Physics, 44(47), 472001. https://doi.org/10.1088/0022-3727/44/47/472001
30. Van Gils, C., Hofmann, S., Boekema, B., Brandenburg, R., & Bruggeman, P. (2013). Mechanisms of bacterial inactivation in the liquid phase induced by a remote RF cold atmospheric pressure plasma jet. Journal of Physics D: Applied Physics, 46(17), 175203. https://doi.org/10.1088/0022-3727/46/17/175203
31. Wargenau, A., Fleißner, A., Bolten, C. J., Rohde, M., Kampen, I., & Kwade, A. (2011). On the origin of the electrostatic surface potential of Aspergillus niger spores in acidic environments. Research in Microbiology, 162(10), 1011-1017. https://doi.org/10.1016/j.resmic.2011.07.006
32. Wu, S., Zhang, Q., Ma, R., Yu, S., Wang, K., Zhang, J., & Fang, J. (2017). Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water. The European Physical Journal Special Topics, 226(13), 2887-2899. https://doi.org/10.1140/epjst/e2016-60330-y
33. Xu, D., Wang, B., Xu, Y., Chen, Z., Cui, Q., Yang, Y., Chen, H., & Kong, M. G. (2016). Intracellular ROS mediates gas plasma-facilitated cellular transfection in 2D and 3D cultures. Scientific Reports, 6(1), 1-14. https://doi.org/10.1038/srep27872
34. Yagyu, Y., Hatayama, Y., Hayashi, N., Mishima, T., Nishioka, T., Sakudo, A., Ihara, T., Ohshima, T., Kawasaki, H., & Suda, Y. (2016). Direct plasma disinfection of green mold spore on citrus by atmospheric pressure dielectric barrier discharge for agricultural applications. Transactions of the Materials Research Society of Japan, 41(1), 127-130. https://doi.org/10.14723/tmrsj.41.127