Abstract: ObjectiveThe best decoloring conditions ( time, temperature and bleaching agent dosage) for horse fat were screened with response surface methodology in order to provide a theoretical basis for industrial production. MethodsDifferent decolorizing agents were used to bleach the deacidified horse fat and the most suitable one was selected.According to the standard of decolorizing rate, the effects of bleaching temperature, time and agents dosage on decolourization rate of horse fat from Xinjiang were evaluated.The optimal combination conditions were identified by Box- Behnken response surface design method.ResultsThe activated clay was identified as the best horse fat bleaching agent.The best decoloring process condition identified by Box-Behnken response surface analysis was bleaching temperature for 61℃, bleaching time for 32 min, and 5.25% dosage of activated clay.The bleaching rate was 71.01% on this condition.ConclusionsRegression equation of response surface methodology was reasonable, and could be used to predict the relationship between experimental factors and response values, determine the horse fat bleaching process parameters.Compared with conventional colorimetric methods, visible spectrophotometry was easy and simple to handle with high sensitivity and good reproducibility.