Cellulose acetate adsorption technique

Control of Juice Bitterness. A number of advances have been reported in this field since it was last reviewed (3). A commercial application of the cellulose acetate adsorption technique for the removal of limonin from citrus juices was undertaken (49). New sorbent gel forms of cellulose esters for adsorption of limonin were developed (50). Knowledge was gained that limonoids are biosynthesized in citrus leaves and translocated to the fruit (12) and that specific bioregulators can inhibit accumulation of XIV in citrus leaves (15). Additional studies were carried out on the use of neodiosmin to suppress limonin and other types of bitterness (30,51). The influence of extractor and finisher pressures on the level of limonin and naringin in grapefruit juice was reported (34). Also, further studies were conducted on the microbial sources and properties of limonoate dehydrogenase (52), the enzyme that converts XIV to XV and can be used to prevent limonin from forming in freshly expressed citrus juices (53). 

A method for the separation of ellipticine (1), 9-methoxyellipticine (2), and 9-hydroxyellipticine (3) using cellulose adsorption chromatography (thin layer or paper) has been developed (27). The technique involves a solvent system consisting of a 50 50 mixture of 1.3 M ammonium sulfate and 96% acetic acid, followed by iodine vapor detection. 

Ion-exchange chromatography is a useful technique for the initial separation of lipids from crude mixtures. Separation of lipids on columns packed with adsorbants like DEAE-cellulose depends partly on ion-exchange with the ionic parts of polar lipids and partly on adsorption of highly polar non-ionic moieties such as the hydroxyl groups of inositol or carbohydrates. Non-polar lipids are eluted with solvents such as chloroform and polar non-ionic lipids and non-acidic lipids are partly resolved by increasing concentrations of methanol in chloroform. Weakly acidic lipids can then be eluted by inclusion of acetic acid in the solvent while strongly acidic lipids... 

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