Combining fuzzy mathematics and response surface method to optimize the process of whey protein gelation

In order to obtain the optimal conditions for protease-induced whey protein gel, the effects of different processing parameters such as pH, temperature, enzyme-to-substrate ratio (E/S) , and xanthan gum on the quality of whey protein gel were studied. The data of whey protein gel was analyzed by response surface method and fuzzy mathematics on the basis of single factor test. Results showed that the textural properties and water holding capacity of enzyme-induced whey protein gel were influenced by all these factors. And the optimal conditions of process were as follows:pH6.5, gelling temperature 47℃, enzyme-to-substrate ratio 0.8%, CaCl22mmol/L, xanthan gum 0.015%. Under this condition, the comprehensive score of the gel was 0.720. The final product showed a light yellow color with a fat-like textural and mouth feeling properties.