Updated publication reference for PubMed record(s): 25299339. In studies presented here, recombinant human serum albumins (rHSA) produced in Oryza sativa (Asian rice) (OsrHSA) from a number of suppliers have been extensively characterized and compared to plasma-derived HSA (pHSA) and rHSA expressed in yeast (Pichia pastoris and Saccharomyces cerevisiae). Modifications of the samples were identified by liquid chromatography-mass spectrometry (LC-MS) with samples further assessed with size exclusion chromatography (SEC), reversed-phase high-performance liquid chromatography (RP-HPLC), capillary electrophoresis (CE) as well as additionally biophysical techniques. LC-MS analysis identified a greater number of hexose-glycated arginine and lysine residues on OsrHSA compared to pHSA or rHSA expressed in yeast. Lot-to-lot variability of OsrHSA glycation from one manufactures supplied products were further identified. The extensive glycation of OsrHSA from multiple suppliers may have further implications for the use of OsrHSA as a therapeutic product.