A reliable and effective sample preparation protocol of MALDI-TOF-MSI for lipids imaging analysis in hard and dry cereals.
A reliable and effective sample preparation protocol of MALDI-TOF-MSI for lipids imaging analysis in hard and dry cereals.
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DOI：
10.1016/j.foodchem.2022.133911
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发表时间：
2022-08
期刊：
影响因子：
8.8
通讯作者：
Yanxia Zhang;Yi-Da Zhang;Yan-Ping Shi
中科院分区：
文献类型：
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作者：
Yanxia Zhang;Yi-Da Zhang;Yan-Ping Shi
上级切片样品制备方案是维持MALDI-TOF-MSI分析数据可靠性的基本保证。尽管在样品制备方面取得了重大进展，但由于其固有的物理化学性质，硬质和干燥谷物中脂质的可视化仍然很困难。因此，设计了一种通过多聚赖氨酸浸泡、导电胶带粘贴和包埋介质固定的冷冻切片制备方法，该方法在不引起分析物离域和明显背景干扰的情况下，保持了谷物中脂类的空间完整性。利用所建立的样品制备方法，对水稻、小麦和大麦（青壳）中的脂类物质进行了高信号强度和清晰的成像。此外，还研究了不同储藏年限大米中脂类物质的空间分布，发现磷脂酰肌醇（PI）和磷脂酰甘油（PG）可用于评价大米的老化程度。本研究为进一步探讨稻米老化机理、稻米品质评价和安全性监测提供了分子水平的指导。
A superior sectioning sample preparation protocol is the basic guarantee for maintaining data reliability in MALDI-TOF-MSI analysis. Despite significant advances in sample preparation, visualization of lipids in hard and dry cereals remains difficult due to their inherent physicochemical properties. Thus, a cryosections preparation method was designed via poly-l-lysine soaking, conductive tape adhesion and embedding medium fixation, which preserved the spatial integrity of lipids in cereals without causing analyte delocalization and obvious background interference. Higher signal intensity and clearer imaging of lipids in rice, wheat and barley (Qingke) were obtained using the established sample preparation method. Moreover, the spatial distribution of lipids was visualized in rice with different storage years, which found that the phosphatidylinositols (PIs) and phosphatidylglycerols (PGs) could be used for evaluation of rice aging degree. Our study provided molecular level guidance for further discussion of rice aging mechanism, rice quality evaluation and safety monitoring.