Adulteration and characterization of orange and grapefruit juices

Summary The chemical composition of orange and grapefruit juices have been reviewed and analytical data tabulated for the more commonly determined components of juices. Some of the less commonly determined minor components have been considered in detail, including the flavanoids, limonoids, carotenoids, oil components, amino acids, proteins, phosphorus compounds, long chain fatty acids, long chain hydrocarbons and nitrogen bases. The significance of analytical data in characterizing juices and in determining adulteration is discussed. Evidence suggests that the very wide natural variation in fruit components necessitates evaluating juices on the basis of a number of parameters, rather than on a single index component. The importance of choosing parameters which give both a ‘powerful’ and ‘safe’ method is stressed. The value of multiple regression analysis and of the X2 distribution test in the statistical appraisal of analytical data is considered.