Search

Alfalfa seeds were directly treated with corona discharge plasma radiation and compared with the control group, which was covered by a Petri dish, blocking the etching effect of ionic wind and thus simulating the effect of a non-uniform electric field. The results showed that corona discharge plasma radiation changed the chemical structure of the seed coat. The peak value of the Fourier transform infrared spectrum of the seed coat at 2 856 cm‒1 and 1 729 cm‒1 changed after treatment, indicating that the wax, lipids, and cellulose in the seed coat may have been degraded. Measurements of the seed floating rate and apparent contact angle in the treated seeds compared to the measurements in the control group indicated that corona discharge plasma radiation also improved the hydrophilicity of the alfalfa seeds. In the control group, the Petri dish cover effectively reduced the physicochemical etching by ionic wind; thus, it appears that ionic wind has a greater influence on the seed coat than does the non-uniform electric field. Scanning electron micrograph images showed that the etching of the seed coat in the treated seeds was severe; the cellulose of the seed coat was degraded, and the surface was cracked, which improved the water absorption capacity of the seed. The seedling height of the seeds treated with corona discharge plasma radiation increased significantly compared to that of the control group, indicating that the physicochemical etching of the ionic wind had resulted in a macroscopic biological effect. This study provides experimental data support for the analysis of surface modification and chemical structure composition of alfalfa seeds treated with corona discharge plasma radiation and also provides a basis for further study of the biological effect mechanism of the corona discharge field.

High-voltage discharge plasma drying (HVDPD) is a non-thermal and efficient drying technique. In this study, we compared the drying characteristics and physicochemical properties of alfalfa dried via HVDPD, hot-air drying (HAD), and natural air-drying (AD) and analyzed the experimental results using infrared spectroscopy, scanning electron microscopy, colorimetry, and other detection techniques. The results showed that HVDPD had a higher drying rate than AD and saved more energy than HAD. Alfalfa dried via HVDPD had the most intact internal structure, the highest rehydration ratio (RR), the best color quality, and the best nutrient retention, resulting in the highest relative quality and feeding value. Therefore, HVDPD is an excellent drying technique for alfalfa, providing a new and effective way to improve the storage, transportation, and drying quality of alfalfa. [ABSTRACT FROM AUTHOR]

The high nutritional value of alfalfa hay makes it a widely utilized component in animal feed. However, the current prevalent drying methods for forage have a significantly detrimental impact on the quality of alfalfa during the drying process. This study investigates the effects of high-voltage corona discharge (HVCD) treatment on post-cut alfalfa. Gradient experiments are conducted by adjusting the air-gap spacing at a voltage of 25 kV. The results demonstrate that as the distance decreases, there is an observed increase in the drying rate, rehydration rate, and color intensity of the HVCD-treated material. HVCD treatment significantly enhances crude protein content, which increases with decreasing air-gap spacing. Meanwhile, it negatively affects lignin, neutral detergent fiber (NDF), and acid detergent fiber (ADF) levels. The relative forage quality (RFQ) of alfalfa reaches its peak at an air-gap spacing of 7 cm. The application of HVCD disrupts the fiber structure and induces significant electroporation effects in cells. Minimal changes in functional groups preserve nutrient integrity. Furthermore, HVCD exhibits lower energy consumption compared to hot air dryers. The HVCD treatment is a highly efficient and effective method, with a gradual improvement in alfalfa hay quality as the air-gap distance decreases. [ABSTRACT FROM AUTHOR]

In this study, corona discharge at atmospheric pressure under an alternating current (AC) field with a multi-needle plate electrode structure was used as mutagen to study the effects of corona discharge field on the hydrophilicity of alfalfa seeds, especially the effects of non-uniform electric field that is frequently ignored. Alfalfa seed were divided into two groups, one group was covered with 1 mm-thick polypropylene petri dish cover that can be approximated as a single factor effect of non-uniform electric field, the other group was directly irradiated by corona discharge field under different parameters. Fourier transform infrared spectroscopy (FTIR) and dual-index sequence analysis were used to detect and compare the spectra of alfalfa seed coats with different treatments. Results showed that the peaks of the seed coat at 2856 and 1727 cm−1 in the treatment group changed, indicating that hydrophobic wax, lipid, and cellulose may be cracked or degraded. Corona discharge field treatment can change the chemical structure of alfalfa seed coats, resulting in the changes in their hydrophilicity. The results of the apparent contact angle and scanning electron microscopy (SEM) and other experiments showed that the change in 19 kV non-covered treatment group was greatest, the petri dish cover can effectively reduce the physicochemical etching of ionic wind, the hydrophilicity of alfalfa seeds improved after corona discharge field treatment regardless of whether there is an ionic effect during irradiation, and the ionic wind has a greater influence on the hydrophilicity of alfalfa seeds than the non-uniform electric field. This study revealed the biological effect mechanism of corona discharge field from the perspective of spectral characteristics and provided experimental data support for the analysis of alfalfa seed surface modification and chemical structure after corona discharge field treatment. Unlabelled Image • The contributions of non-uniform electric field and ionic wind on hydrophilicity of seed was studied. • Dual-index sequence analysis was used to compare different treatment groups. • Corona discharge field treatment can improve the hydrophilicity of alfalfa seeds. • IR spectrum results indicate changes in chemical structure of the treatment group. • For hydrophilicity, the contribution of ionic wind is more than nonuniform electric field. [ABSTRACT FROM AUTHOR]