# Study of the Effects of Plasma Pretreatment on the Microstructure of Peanuts
## 4 Conclusions  
This study investigates the impact of cold plasma treatment on peanut microstructures under a scanning electron microscope (SEM). It reveals significant effects based on treatment power, duration, and gas type on both peanut seed coat and embryo structure. As plasma treatment power increases from 100 W to 500 W, the etching intensity on the peanut seed coat gradually strengthens. Surface roughness and concavity become more pronounced, and lipid particles begin to exude and cover the seed coat. At 500 W, distinct pores appear on the seed coat surface, and cell structures become blurred due to lipid particle exudation, resulting in complete coverage by lipids. Prolonged treatment duration, especially at 150 s of plasma treatment, further enhances these changes, with protein particles becoming more liberated and cracks more evident. Regarding gas types, oxygen (O\({}_{2}\)) has the most significant impact, followed by argon (Ar), while helium (He) exhibits the weakest influence. Oxygen-treated peanuts show increased internal pores and denser lipid particles, whereas the Ar-treated group experiences fewer lipid particle escapes and increased starch granule exudation. These varying effects highlight the importance of gas selection on peanut structural modifications.  
Figure 7: Internal structure of peanuts under scanning electron microscope after different treatment durations. Note: The left column shows SEM images at 200\(\times\) magnification. (**a**) Corresponds to the control group peanuts. (**c,e,g,i**) Correspond to peanuts subjected to cold plasma treatment with He at 200 w for 150 s, with He at 500 w for 60 s, with O\({}_{2}\) at 200 w for 60 s, and with Ar at 200 w for 60 s, respectively. The right column shows SEM images at 500\(\times\) magnification. (**b**) Corresponds to the control group peanuts. (**d,f,h,j**) Correspond to peanuts subjected to cold plasma treatment with He at 200 w for 150 s, with He at 500 w for 60 s, with O\({}_{2}\) at 200 w for 60 s, AND with Ar at 200 w for 60 s, respectively.  
The study demonstrates that plasma treatment significantly alters the microstructure of peanut seed coats and embryos. Beyond affecting seed health and integrity, it may also impact physical properties such as permeability and water absorption. These modifications have far-reaching implications for peanut breeding, oil extraction, and processing. Additionally, careful consideration of treatment parameters to regulate changes in peanut microstructure, such as power, duration, and gas type, is crucial for optimizing peanut quality and processing performance. This study provides a theoretical basis and practical guidance for directional selection for subsequent storage, breeding, oil extraction, food processing, etc. However, the changes in the quantitative relationships occurring in pretreated peanuts and their application in the processing of actual products are yet to be investigated in depth. Future research should explore the long-term effects of plasma treatment on peanut quality and how this approach can enhance nutritional value and food safety.  
Y.W.: Writing--original draft; Q.Y.: Project administration, Methodology, Formal analysis; X.L.: Writing--review and editing; J.Y.: Validation; Z.Z.: Funding acquisition, Resources; X.Z.: Supervision. All authors have read and agreed to the published version of the manuscript.  
This work was financially supported by a Special Project Funded by Surplus Funds at the Academy of the National Food and Strategic Reserves Administration (No: JY2304).  
Not applicable.  
The data presented in this paper are available for verification by readers.  
We express our gratitude to the reviewers for their invaluable guidance on this article. The authors declare no conflicts of interest.