Unal Kubra, Alpas Hami, Aktas Hakan, Oztop Mecit H
Department of Food Engineering, Faculty of Engineering, Middle East Technical University, 06800 Ankara, Turkey.
Turkish Patent and Trademark Office, 13 Hipodrom Street, 06560 Ankara, Turkey.
J Food Sci Technol. 2020 Oct;57(10):3739-3747. doi: 10.1007/s13197-020-04406-5. Epub 2020 Apr 13.
NMR relaxometry was used to investigate the proton relaxation distribution of the tomato seeds and analyze the damages of the three different processes on the cell membrane integrity of the tomato seed. Tomato seeds were subjected to osmotic stress (OS) (10, 20, 30% NaCl solutions), ultrasonication (US) (5, 10 and 20 min) and high hydrostatic pressure (HHP) (300, 400 and 500 MPa for 15 min at 20 °C). Four peaks were observed in the NMR relaxation spectra of tomato seeds due to multiexponential relation behavior of the plant cell. Each peak corresponds to different water proton compartment within the cell. According to the results, all the three treatments resulted in cell permeabilization and disruption of cellular compartmentalization. Among the treatments, HHP at 500 MPa for 15 min at 20 °C resulted in the most detrimental effect in the cell structure and OS treatment with 10% NaCl solution caused the least changes in the cell structure. In order to further analyze the extent of damage to the cell, tomato seeds exposed to OS, US and HHP were also analyzed by scanning electron microscopy (SEM). These results have demonstrated that NMR relaxometry is a useful tool to investigate the cell integrity of tomato seeds subjected to different treatments.
采用核磁共振弛豫测量法研究番茄种子的质子弛豫分布，并分析三种不同处理对番茄种子细胞膜完整性的损伤。将番茄种子分别置于渗透胁迫（OS）（10%、20%、30% NaCl溶液）、超声处理（US）（5、10和20分钟）以及高静水压（HHP）（20℃下300、400和500 MPa处理15分钟）条件下。由于植物细胞的多指数关系行为，在番茄种子的核磁共振弛豫谱中观察到四个峰。每个峰对应细胞内不同的水质子区室。结果表明，所有三种处理均导致细胞通透性增加和细胞区室化破坏。在这些处理中，20℃下500 MPa处理15分钟的HHP对细胞结构的破坏作用最大，而10% NaCl溶液的OS处理对细胞结构的影响最小。为了进一步分析细胞损伤程度，还通过扫描电子显微镜（SEM）对经OS、US和HHP处理的番茄种子进行了分析。这些结果表明，核磁共振弛豫测量法是研究经不同处理的番茄种子细胞完整性的有用工具。
