The analysis of UV-VIS spectrum was used for testing changes through 36 days and the impact of external conditions (reduced temperature (R), microwave radiation (M) and normal conditions (NC) for comparisons) on the stability of: BSA and BSA-Fe2+ complexes after different treating procedure. The increase of BSA absorption with increasing concentration of Fe2+ was observed. Increased absorption of BSA, and BSA-Fe2+ with time, related probably to conformational changes present in the protein and changes in electrostatic reactions within the BSA-Fe2+ complexes. Examination of the impact of an external factor on stabilization of the protein and complexes showed a tendency to keep the stability under reduced temperature and a trend with accelerated protein and complex aging under microwave radiation. The observed tendencies to changes under the influence of external factors became more significant in time. These effects were most probably related to changes of the protein structure and time, while the observed trend of accelerating the changes was impacted by the applied external factors.