Abstract: Nitrosohemoglobin was prepared from porcine hemoglobin and glycosylated with chitosan, which was selected in consideration of thermal stability. The effects of mass ratio of nitrosohemoglobin to chitosan, pH, temperature and reaction time on the glycosylation of nitrosohemoglobin were probed by one-factor-at-a-time method. Subsequently, response surface methodology, based on Box-Benhnken experimental design, was used to optimize pH, temperature and reaction time for achieving maximum absorbance at 450 nm of reaction products. The optimal glycosylation conditions of nitrosohemoglobin were determined as follows: mass ratio of nitrosohemoglobin to chitosan, 4.16:1, pH 5.6, temperature 50.5 ℃ and 15.7 min.

Key words: hemoglobin, nitrosohemoglobin, chitosan, glycosylation