STUDIES ON THE MEMBRANE CONCENTRATION OF WATERMELON JUICE

Watermelon juice has several potential attributes in addition to its r efreshing taste, aroma and attractive colour. It is also reported to h ave diuretic properties. The juice contains good amount of soluble sol ids making concentration an attractive process especially using membra nes. Studies were carried out on concentration of watermelon juice usi ng a DDS lab model RO unit with different types of membranes. The juic e could be concentrated from 6.5 degrees to 24 degrees brix using CA-9 92. HR-95 and EC-50 gt 5 MPa operating pressure. Average permeate flux was found to 15 to 17 L/m(2)/h depending on membrane type. Rejection characteristics of the membranes showed that rejection of total solids are reducing sugar was highest with CA-992 and lowest with HC-50 and rejection of acids was highest with HR-95 and lowest with HC-50. Data on the physicochemical characteristics of the semiconcentrate are pres ented vis-a-vis the feed juice.