OPTIMIZATION OF ENZYMATIC PEELING OF GRAPEFRUIT

Several commercial enzyme preparations were evaluated as to their suit ability for enzymatic peeling of grapefruit. The best pectinases were found to be those which contained high concentrations of polygalacturo nase, pectin-transeliminase, and pectin esterase. A cellulase was also needed to achieve satisfactory peeling. The optimum process included scalding, scoring, vacuum infusion of the enzyme solution, pH stabiliz ation, incubation (35 min at 40-degrees-C), and rinsing. The enzymatic ally peeled fruit had a good appearance, was firmer than that obtained by the conventional method. The enzyme solutions could be used for se veral consecutive peeling runs, after restoring them to their initial activity. Enzymatic digestion of grapefruit segment membranes was also achieved, and a very firm and shiny product was obtained.