*2.6. Detection of Early Glycation (Amadori) Products: Quantification of Fructosamine*

NBT assay was used to determine fructosamine content; the previously used protocol was used [42]. Briefly, 0.5 mM NBT was mixed with samples (0.5 mg/mL) and incubated in 100 mM sodium carbonate buffer of pH 10.4. The reaction mixture was incubated for 2 h at 37 ◦C, and reading was taken at 530 nm. The concentration of fructosamine was evaluated using its molar extinction coefficient value, i.e., 12,640 M−<sup>1</sup> cm−<sup>1</sup> [43].
