Application of rheological parameters and mixture design to optimize the formula of cloudy pumpkin juice beverages

This study utilized pumpkin as raw material to produce juice and optimized parameters by orthogonal test and mixture design.The optimal dosage of pectinase, xylitol and citric acid were determined by orthogonal test, and the influences of xanthan gum, guar bean gum and CMC on the stability of the beverage were also studied. The regression models which can reflect the relation of quality and beverage components including upstream viscosity, downstream viscosity, thixotropic loop area and sensory evaluation value was established. The analysis of variance and demonstration test indicated that the models and regressive equation had a high level of significance.The results showed that the utilization ratio of pumpkin juice reached 94.2%by adding 15 U/g pectinase.The optimal proportions of the pumpkin beverage are as following: pumpkin juice 30%, and xylitol10%, the optimal combination of the compound stabilizer is xanthan gum 0.089%, guar gum 0.2%, CMC 0.711%. The maximum value of sensory evaluation is 89.92.