Most modern laundry detergents contain enzymes such as proteases, amylases, and lipases for more efficient removal of stains containing proteins, carbohydrates, and lipids during wash at low temperature. The function of the lipases is to hydrolyse the hydrophobic triglycerides from fats and oils to the more hydrophilic lipids diglycerides, monoglycerides and free fatty acids. Here, we use MALDI imaging to study the effect of enzymatic degradation of triglycerides by lipases directly on the textile surface. Textile samples were created by using swatches of different textile blends, adding a lipid stain and simulating washing cycles using well-defined detergents with lipase concentrations ranging between 0 and 0.5 ppm. After washing, the textile swatches as well as cryo-sections of the swatches were imaged using MALDI imaging in positive ion mode at pixel sizes of 15–75 μm. Similar samples were imaged by DESI-MSI for comparison.

Despite the rough surface and non-conductive nature of textile, MALDI imaging of glycerides on textile was readily possible. The results show extensive enzymatic degradation of triglycerides into diglycerides, and images suggest that this degradation takes place in a quite heterogeneous manner as also observed in images of cross-sections. DESI-imaging reveals the same kind of enzymatic degradation, but with a more homogeneous appearance. While the enzymatic degradation is exemplified in a few images, the overall degradations process was monitored by extraction of ion intensities from 298 individual ion masses of mono-, di- and triglycerides and free fatty acids.

MALDI imaging of glycerides was possible directly from a textile surface, allowing visualization of the enzymatic degradation of fatty stains on textile during the laundry process. The images showed an inhomogeneous presence of diglycerides after lipase treatment both in planar images of the textile surface as well as in cross-sections suggesting a non-uniform enzyme effect or extraction of the lipase reaction products from the textile.

大多数现代洗衣粉都包含酶（例如蛋白酶，淀粉酶和脂肪酶），以便在低温洗涤过程中更有效地去除含有蛋白质，碳水化合物和脂质的污渍。脂肪酶的功能是将疏水性甘油三酸酯从油脂中水解为亲水性更高的脂质甘油二酸酯，甘油单酸酯和游离脂肪酸。在这里，我们使用MALDI成像技术来研究脂肪酶直接在纺织品表面上对甘油三酸酯进行酶促降解的作用。通过使用不同纺织品混合物的色板，添加脂质污渍并使用脂肪酶浓度在0至0.5 ppm之间的明确定义的洗涤剂模拟洗涤周期来创建纺织品样品。洗完之后 使用MALDI成像以正离子模式在15–75μm像素大小下对纺织品样品以及样品的冰冻切片进行成像。类似的样品通过DESI-MSI成像以进行比较。

尽管纺织品具有粗糙的表面和非导电性质，但很容易在纺织品上进行甘油酯的MALDI成像。结果表明，甘油三酸酯被广泛地酶降解为甘油二酸酯，并且图像表明这种降解以非常异质的方式发生，这也可以在横截面图像中观察到。DESI成像显示出相同的酶促降解，但外观更均一。虽然在一些图像中举例说明了酶促降解，但通过从298种甘油一酸酯，甘油二酸酯和甘油三酸酯以及游离脂肪酸的离子强度中提取离子强度来监控整个降解过程。

可以直接从纺织品表面对甘油酯进行MALDI成像，从而可以在洗涤过程中可视化纺织品上脂肪污渍的酶促降解。图像显示在脂肪酶处理后，在纺织品表面的平面图像以及横截面中均存在不均匀的甘油二酯，这表明酶作用不均匀或从纺织品中提取脂肪酶反应产物。