Analysis of Moisture Migration and Microstructural Characteristic of Green Sichuan Pepper ( Zanthoxylum armatum ) during the Hot-Air Drying Process Based on LF-NMR

Bin Li, Chuandong Liu, Hang Luo, Chongyang Han, Xuefeng Zhang, Qiaofei Li, Lian Gong, Pan Wang () and Zhiheng Zeng ()
Additional contact information
Bin Li: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
Chuandong Liu: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
Hang Luo: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
Chongyang Han: College of Engineering, South China Agricultural University, Guangzhou 510642, China
Xuefeng Zhang: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
Qiaofei Li: College of Engineering and Technology, Southwest University, Chongqing 400715, China
Lian Gong: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
Pan Wang: Key Laboratory of Agricultural Equipment Technology for Hilly and Mountainious Areas, Ministry of Agriculture and Rural Affairs, Chengdu 610066, China
Zhiheng Zeng: College of Intelligent and Manufacturing Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China

Agriculture, 2024, vol. 14, issue 8, 1-18

Abstract: To have a deeper understanding on the moisture migration patterns and microstructural changes of Green Sichuan Pepper during the hot-air drying process, the low-field nuclear magnetic resonance (LF-NMR) technology and scanning electron microscopy (SEM) methodology were adopted to analyze the moisture distribution, migration patterns and microscopic structural changes under different drying temperatures (45, 55 and 65 °C). The LF-NMR scanning results showed that the internal moisture of the Green Sichuan Pepper mainly includes bound water, immobilized water and free water, which can be respectively symbolized by the relaxation time ranges of T 21 (0.1–10 ms), T 22 (10–500 ms) and T 23 (500–10,000 ms). The immobilized water accounts for 83.72% of the internal water, resulting in the significant drying difficulty of Green Sichuan Pepper. During the drying process, the content of immobilized water and free water exhibited a decreasing trend, while the bound moisture content initially increased and then decreased. In addition, the LF-NMR analysis showed that the parameters peak area A 2 demonstrated a high correlation with the moisture content of Green Sichuan Pepper, enabling the prediction of moisture content changes during the drying process. Additionally, the SEM results showed that the pore degree and pore density on the pericarp surface of Green Sichuan Pepper perform significant changes during the drying process, which might be a good explanation for revealing some commonly recognized drying phenomena on Green Sichuan Pepper hot-air drying. In summary, the findings presented in the present work provide some new insights into the moisture distribution, migration patterns and microstructural changes of Green Sichuan Pepper, which can offer theoretical guidance for optimizing the drying process of Green Sichuan Pepper.

Keywords: Green Sichuan Pepper; low-field nuclear magnetic resonance (LF-NMR); scanning electron microscopy (SEM); moisture distribution; microscopic structural changes (search for similar items in EconPapers)
JEL-codes: Q1 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 (search for similar items in EconPapers)
Date: 2024
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2077-0472/14/8/1361/pdf (application/pdf)
https://www.mdpi.com/2077-0472/14/8/1361/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jagris:v:14:y:2024:i:8:p:1361-:d:1456372

Access Statistics for this article

Agriculture is currently edited by Ms. Leda Xuan

More articles in Agriculture from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().