Effect of enzymatic treatment on the viscosity of raw juice and anthocyanins content in the microfiltrated blackberry juice

Abstract

Fruit juices consumption has increased in recent years due to the perception of juices as a natural source of compounds that provide health benefits, such as anthocyanins, an important natural antioxidant. For the industrial production of blackberry, the juice microfiltration process is commonly used, but due to the high viscosity of this fruit, an enzymatic pretreatment is necessary. The objectives of this study were to select the operating variables (temperature and enzyme concentration) for the juice pretreatment and to evaluate its effect on the anthocyanins content in clarifi ed blackberry juice. An experimental design was carried out to evaluate the rheological behavior of the juice as a function of temperature and enzyme concentration. The experimental data was analyzed by Ostwald-de-Waele model. The data of apparent viscosity as a temperature function was fi tted by Arrhenius equation. The conditions of 35°C and 4 ml of enzyme R apidase/kg of blackberry juice® TF from DSM Food Specialities were se...