Resumen de Clarification of reconstituted frozen orange juice concentrate by continuous flow centrifugation for limonin glucoside solid phase extraction
A. P. Breksa, G. D. Manners, Phil Ibarra
BACKGROUND: The suitability of continuous flow centrifugation for the clarification of reconstituted frozen orange juice concentrate prior to its application to a solid phase extraction column for the isolation of limonin glucoside was evaluated. Clarification experiments spanning three flow rates (325, 588 and 875 mL min−1) and three rotor speeds (equivalent to 2130, 8521 and 19 172 × g) were conducted in a simple factorial design. RESULTS: With increasing rotor speed or decreasing flow rate the average particle size, colour parameters (CIE L*, a*, b*) and residual solids in the resulting centrifugates were found to decrease, whereas juice characteristics including pH, conductivity, °Brix and limonin glucoside content were unchanged by the clarification process. Mean particle size in the resulting centrifugates ranged from 1.14 to 79.31 µm. The most effective clarification was obtained using a 325 mL min−1 flow rate in conjunction with the maximum rotor speed. Suitability of the centrifugates for processing by solid phase extraction was tested through a two-step process, in which the centrifugates were first screened using small columns, followed by application of the centrifugate to a larger self-packed column (6.5 cm × 20 cm) containing SP-70 Sepabeads. CONCLUSION: Centrifugates from two conditions (325 and 588 mL min−1 at the maximum rotor speed) were suitable for direct application to both columns. It was found that up to 19 L of these centrifugates could be applied to the 6.5 cm × 20 cm column without clogging or experiencing a decrease in flow rate. Analysis of the column effluent revealed that 11 L of centrifugate was sufficient to saturate this column. Published in 2008 by John Wiley & Sons, Ltd.
