Abstract: In the paper,response surface methodology was used to investigate the main effects and interactions of transglutaminase (TGase, 0～0.8%), mixed phosphates (0～0.5%),к-carrageenan(0～0.8%) and casein(0～5%) on hardness of chicken breast muscle sausage, with four factors and thee levels Central Composite Orthogonal Design. Results showed that TGase and casein could increase hardness significantly(p<0.05), while mixed phosphate and к-carrageenan had no increasing effect(p>0.05). Recongress equation of hardness was made up to calculate chicken sausage hardness. In the end,optimal ratio of the additives was: TGase(0.8%), mixed phosphate(0%),к-carrageenan(0.8%) and casein(0～5%) with the hardest sausage(705.517g).

Key words: response surface methodology, transglutaminase, mixed phosphate, к-carrageenan, casein, chicken sausage, hardness