Research On Preparation Of Co-Immobilized Esterification Enzyme And Glucoamylase And Its Effect On Accelerating Maturity And Clarification Of Shanxi Aged Vinegar

Now the most important problems of Shanxi aged vinegar are the long time for maturity and brewing and storage process will form turbidity and precipitation. The purpose of this research is to accelerating maturity and clarification of new vinegar by co-immobilized and the sodium alginate and xanthan gum as carriers. According to the single factor experiment and orthogonal experiment, the best process condition of immobilized protease was determined. The enzymatic properties of the co-immobilized enzyme were tested. Optimum conditions which the co-immobilized enzymes accelerating aging and clarification were obtained through single factor experiments and response surface optimization test, then analyzed the effect of co-immobilized enzymes on the composition of vinegar. The main results were as follows:The total concentration of gel was 1.4g/100mL, the ratios of SA to xanthan gum was 5:1, the amount of esterification enzyme was 3.5%, the amount of glucoamylase was 5.0%, absorption time was 6 h, concentrations of calcium chloride was 2.0 g/100 mL, immobilization time was 1.0h. There was no variation in the optimum pH and optimum temperature of the free enzyme. Compared with their free enzyme, thermal stability was enhanced, the kinetic parameter Km was higher than the free esterification enzyme and lower than the free glucoamylase. Optimum conditions were obtained by the optimization of Box-Beknhen central composite experimental design and response surface analysis:the total ester content in vinegar can reach 1.52677 g/100mL, the transmittance will be 93.6706%. Compared with the original vinegar, after vinegar in esters, ketones, hydrocarbons and other heterocyclic compounds were increased. Evaluated by sensory the taste was soft slightly and stimulus was weakened, its body was transparent.