Coupling of pressure-driven membrane technologies for concentrating, purifying and fractionizing betacyanins in cactus pear (Opuntia dillenii Haw.) juice

摘要

An integrated process coupling crossflow micro and ultra or nanofiltration was applied to separate the betacyanins in cactus pear juice (30 degrees C). Four microfiltration ceramic membranes (0.1-0.2 mu m, 1.8-3.3 bar) and 4 ultra/nanofiltration organic membranes (0.2-4.0 kDa, 5-30 bar) were tested. Microfiltration was a first step to remove insoluble solids with low retention of soluble solids. By coupling with enzymatic liquefaction, permeate flux Jp was increased by 2 and the retention of betacyanins was limited. Ultra/nanofiltration was then used for solute separation. Retentions of solutes could be modulated by varying membrane/pressure combinations that favor rather the concentration of all the solutes or rather the purification of the betacyanins with respect to the total dry matter. Retention of individual betacyanins could be a little different which also made possible fractionation. Simulations using simple models allowed to evaluate the interest of the process for concentrating, purifying and fractionating betacyanins with a possible diafiltration step.