Enzyme-Aided Treatment of Fruit Juice: A Review

Enzymatic treatment is a common method of fruit juice production that facilitates juice extraction from plant cells. The choice of enzyme depends on the fruit composition. Pectinase and cellulase are the most popular enzymes while amylase remains less wide-spread. For some raw materials, enzymatic procedures are more efficient than mechanical comminution or thermal processing. The fruit juice industry uses enzymes for streamlining. Enzymes maximize juice extraction from raw materials and improve such processes as pressing, solid settling, and solid removal. Juices that underwent enzymatic treatment are clear and, as a result, more aesthetically appealing to consumers. The review covered the most recent and influential publications on the enzyme treatment of fruit juices (2000–2021). The list of enzymes included pectinase, cellulase, and amylase. The research included the factors that affect the juice fermentation process, i.e., hydromodule, enzyme concentration, incubation time, temperature, and enzyme combination. The methods included data extraction, data analysis, and data compilation, as well as literature search and screening. The review focuses on the effects that individual parameters have on specific responses, e.g., yield, viscosity, total soluble solids, acidity, turbidity, clarity, pigment concentration, phenolic content, color, and solids. A greater enzyme concentration, incubation time, and temperature decrease the viscosity of juice and turbidity but cause color changes. If used in different combinations and at different concentrations, enzymes boost the production of bael pulp, banana, sapodilla, durian, pawpaw, grape, white pitaya, and water melon juices. A longer incubation period improves the production of bael pulp, citron, date, and pawpaw juices. However, higher incubation temperatures seem to have no positive effect on the juice yield. Cellulases, pectinases, amylases, and their combinations are able to produce more fruit juice of higher quality with a more favorable time-temperature combination of incubation. The optimal enzyme concentration, incubation time, and temperature can increase the juice yield. Therefore, enzymatic treatment is an effective method that ensures favorable properties of the finished product.