MS_FTIR_figure 3 and its associated data

Figure 3. Brightfield optical image and synchrotron-IR maps of lipids and lipid digestion products in WPC 80-emulsified milk fat globules (a) before digestion; (b) after 60 mins digestion in the gastric phase with pD adjusted to 6.9; and (c) after 60 mins digestion in the small intestinal phase. Chemical maps representing the distribution of different chemical compositions in the fat globules were produced based on integrated area under different peaks, including ν(C=O) of total lipids (mainly triglycerides*, also diglycerides, monoglycerides and free fatty acids) at ~1745 cm-1; ν(C–H) of unsaturated hydrocarbon at ~3006 cm-1; ν(C=O) of free fatty acids at ~1710 cm-1; and ν(COO-Ca) of fatty acid-calcium soaps at ~1578 cm-1 respectively. Area under the peaks were integrated from second order derivatives of the IR spectra to resolve overlapping bands and visualise spectral changes. Figure S4 shows FTIR maps for peaks integrated from the raw IR spectra. Intensity range of the false colour heatmap for each chemical species was set constant.