|Manners, Gary - USDA RETIRED|
|Ibarra, Phil - USDA-SF WORKS|
Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 10, 2008
Publication Date: August 8, 2008
Citation: Breksa III, A.P., Manners, G.D., Ibarra, Jr., P. 2008. Clarification of reconstituted frozen orange juice concentrate by continuous flow centrifugation for limonin glucoside solid phase extraction. Journal of the Science of Food and Agriculture. 88:2213-2218. Interpretive Summary: The clarification of reconstituted frozen orange juice concentrate (FOJC) by continuous-flow centrifugation in preparation to being applied to a solid phase extraction column for the isolation of limonin glucoside has been evaluated. Continuous flow centrifugation may be used to generate centrates suitable for immediate processing by solid phase extraction or column chromatography. For the pilot or production scale isolation of limonin glucoside from FOJC, clarification by this method may offer a significant reduction in processing time when compared to the use of standard floor centrifuges.
Technical Abstract: The clarification of reconstituted frozen orange juice concentrate by continuous-flow centrifugation in preparation to being applied to a solid phase extraction column for the isolation of limonin glucoside has been evaluated. Clarification experiments spanning over three different flow rates (325, 588, 875 mL/min) and three different rotor speeds (5, 10, 15 krpm) were conducted in a simple factorial design. With increasing rotor speed or decreasing flow rate the average particle size, color parameters (CIE L*a*b*) and residual solids in the resulting centrates were found to decrease, whereas juice characteristics including pH, conductivity, % Brix and limonin glucoside content were unchanged by the clarification process. Average particle size in the resulting centrates varied from 1.14 to 79.31 micro m. The most effective clarification was obtained using a 325 mL/min flow rate in conjunction with the 15 krpm rotor speed. Suitability of the centrates for processing by solid phase extraction was tested through a two-step process, in which the centrates were first screened using small columns, followed by application of the centrate to a larger self packed column (6.5 x 20 cm) containing SP70. Only two clarification conditions (325 and 588 mL/min at 15 krpm rotor speed) were found suitable for direct application to both columns. We found that up to five gallons of these centrates could be applied to the 6.5 x 20 cm column without clogging or experiencing a decrease in flow rate. Analysis of the column effluent revealed that three gallons of centrate were sufficient to saturate this column.