Preconcentration of Apple Juice by Reverse Osmosis

Abstract

ABSTRACT Single strength apple juices (10° Brix) were processed by reverse osmosis to 20‐25°Brix, primarily at 20°C. A pilot scale plate and frame UF‐RO system equipped with cellulose acetate (CA) membranes, CA‐865 and/or CA‐990, or high resistance (HR) membranes, HR‐95 and/or HR‐98, was operated at pressures of 35‐45 bar. At 45 bar, the larger pore‐sized CA‐865 possessed the highest processing capacity of 26.9 L/m 2 /hr (from 10°Brix to 20°Brix) and concentration limits of 35° Brix, but had low recovery of solutes and flavor volatiles. The HR‐95 and HR‐98 had similar processing capacities of 15‐16 L/m 2 /hr and concentration limits of 20‐25° Brix at 45 bar. The recoveries of 97% solutes and 87% apple flavor volatiles were obtained using either the HR‐95 or the HR‐98.