Bitter Orange Juice Research Articles

High-performance liquid chromatography of diastereomeric flavanone glycosides in Citrus on a β-cyclodextrin-bonded stationary phase (Cyclobond I)

The flavavone glycosides prunin, naringin, neohesperidin and narirutin were separated into their diastereomers by high-performance liquid chromatography elution in the reversed-phase mode on a β-cyclodextrin bonded stationary phase (Cyclobond I). Application to the analysis of Citrus extracts showed that immature grapefruit fruits contained almost entirely (2 S)-naringin and (2 S)-prunin, whereas in grapefruit juice both diastereomers of naringin and narirutin were present (about 60% S and 40% R isomers). In bitter-orange juice only (2 S)-neohesperidin was detected and sweet orange juice contained racemic narirutin. Benzoylated flavanone glycosides (naringin, prunin) were also separated on Cylcobond I in the normal-phase mode.

New sorbent gel forms of cellulose esters for debittering citrus juices

AbstractMethods are described for the preparation of cellulose esters in gel forms suitable for the removal of the bitter principle limonin from orange juice without requiring prior centrifugation of the juice and without introducing sorbent fines into the product. Bitter orange juice was successfully debittered by holding several days in containers with linings of the esters in gel form, by batchwise agitation with gel cubes or beads, and by passage through columns packed with these materials. These processes provide the basis for methods suitable respectively for in storage, batchwise or inline debittering treatments on an industrial scale. Cellulose acetate gel beads were used to debitter eight successive batches of juice, the sorptive capacity of the beads being regenerated by washing with water between treatments. The preparation of these gel beads batchwise or by a continuous drop‐tower procedure is described, using only materials approved for use in food processing.

Removal of limonin from bitter orange juice

AbstractPolyamides are shown to be effective adsorbents for removal of the bitter principle, limonin, from pasteurised Washington Navel orange juice. The extent of limonin removal varies with different juices, but sufficient can be removed by one or two treatments to bring the concentration below the organoleptically detectable level. The commercial use of polyamides to prepare non‐bitter juices from Navel oranges is discussed.