**8. Liquefaction and stabilisation of juice**

From the chemical point of view, liquefaction is the process of converting a substance from its solid or gas phase into a liquid phase. As for food technology, liquefaction means the process of turning insoluble macroparticles of tissues into smaller and soluble particles via degrading enzymes [55]. Vacuum infusion of pectinases [56] has a commercial application to soften the peel of citrus fruits.

Nectars are cloudy fruit juices mixed with syrup and citric acid to produce a ready-to-drink beverage. A serious defect of nectars is the precipitation of the cloudy particles in the bottom of the container, forming a gel and leaving a clear supernatant layer, which consumers decline. The addition of *exo-*pectinases could

#### **Figure 7.**

*Effect on banana juice of the pectinase extract PGzyme produced by Aspergillus sojae (ATCC 20235) on Banana juice as clarification and stabilization enzyme [57].*

#### *Fungal Pectinases in Food Technology DOI: http://dx.doi.org/10.5772/intechopen.100910*

improve the stability of cloudy particles and render stable homogeneous nectar. Commercial enzymes that have high PG and PNL activities combined with cellulases and hemicellulases are used to decrease the viscosity and to keep cloud stability. In this respect, a crude extract that contained a mixture of pectinases (exo-PG, endo-PG and PNL) produced by *Aspergillus sojae* ATCC 20235, which was named PGzyme, was successfully employed to clarify a cloudy banana juice. As a result, the cloudy juice was converted into a crystal stable translucent drink (**Figure 7**) [57].
