Biochemical Basis of Bitterness in Citrus Fruit Juices and Biotech Approaches for Debittering

Abstract
This review discusses different facets of the subject of bitterness in, and debittering of, citrus juices. For this purpose, the tone is set up by giving an account of the biochemical properties of naringin, responsible for “immediate” bitterness, and of limonin, responsible for “delayed” bitterness. Their structures are ellucidated, and enzymes participating in their catabolic pathways are assigned. Thereafter, methods used to determine bitterness, based on the principles of colorimetry, chromatography, and biochemistry, are discussed, including their advantages and disadvantages. Finally, different physicochemical and biotechnological approaches for debittering are discussed.