Abstract: To optimize the preservation effect of the compound preservative on konjac tofu, tofu made from konjac powder was used as the experimental object in this study. Based on the results of the single-factor test, the response surface method was adopted, under normal temperature storage conditions, to optimize the preservation formula of chitosan and ε-polylysine concentrations for soaking konjac tofu. Meanwhile, the weight loss rate, sensory score, pH value and other indicators of konjac tofu treated with the optimal formula were determined to evaluate the preservation effect of the method. The results show that the optimal formula for inhibiting quality deterioration of konjac tofu is： the addition amount of sodium carbonate 5.0 g+chitosan 1.0%+ε-polylysine 0.37 g·L-1; on the fifth day of storage, the weight loss rate of konjac tofu treated with the best formula was significantly lower than that of the other treatment groups, while the sensory score, comprehensive index, pH value and hardness were significantly higher than those of the other treatment groups. Therefore, compared with a single preservative, the best formula has a synergistic effect on delaying the spoilage of konjac tofu and prolonging its preservation effect.

Key words: response surface method, preservation, Konjac tofu, chitosan, ε-polylysin