Comparative study of juice production by pulsed electric field treatment and enzymatic maceration of apple mash

Abstract

The application of pulsed electric fields (PEF) to apple mash as an alternative to enzymatic mash maceration (EM) was investigated on a pilot plant scale. Chemical composition of the juices obtained by different processes was similar, except for phenolic content and antioxidative capacity, thus proving substantial equivalence of the juices. However, PEF led to an enhanced release of nutritionally valuable phenolics into the juice. Sensory properties of the juices did not significantly differ when PEF pre-treatment was applied. Total juice yield amounting to approx. 85% was not increased by PEF treatment and was irrespective of the different mash pre-treatments, however, juice release was delayed after PEF application (W = 10 kJ/kg), whereas EM enhanced the de-juicing process. In contrast to EM, genuine pectin quality was retained by PEF processing, which allows sustainable pomace utilisation and additional commercial benefit through its commercialisation. Within a storage time of 40 weeks juice composition remained unchanged.