Fruit Juice and Beverage Processing

In the production of fruit juice, wine, beer, and other beverages, the raw juice is in a slurry (known as a mash ) with solid fruit. The juice is separated from the fruit by a combination of filtration and/or centrifugation. The separation operation is a cost trade-off the more powder, time, and wash water used, the higher the yield of juice, but the more costly the process. There are also trade-offs of clarity and yield. 

Cellulase enzymes break down cellulose and beta-glucan associated with the cell walls, thereby decreasing the viscosity of the mash and increasing the ease of the juice recovery. The conversion of cellulose and beta-glucans into soluble 

Apple juice is the juice most commonly produced using cellulase enzymes, followed by cranberry juice, orange juice, and grape juice. 

Although the benefits of cellulase are significant in juice production, pectin-ases are more important in these systems. Fruits contain high levels of pectin, and pectin is efficiently hydrolyzed by pectinases. Pectinase increases juice yields by 10% to 50%, while cellulase provides an enhancement of 5% to 15%. The effects of pectinase and cellulase together are additive and can even be synergistic. 

Another concern in using cellulase in beverages, particularly beer and wine, is the possibility of changes in flavor. Although increasing flavor extractability is often desirable, many beer and wine brand names maintain a constant flavor that is undesirable to change. 

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