FATTY-ACIDS OF ITALIAN BLOOD ORANGE JUICES

This paper reports the composition of fatty acids in two types of Ital ian blood orange juices: one is a not-from-concentrate (NFC) juice and the other is a reconstituted-from-concentrate (RFC) juice. Both juice s have been purposely processed from the same stock of blood oranges. Fatty acids have been separated and identified as methyl esters by GC/ MS, and 11 of them have been determined by GC-FID. Four acids (Linolei c, palmitic, linolenic, and vaccenic) constitute similar to 88% of tot al acids. Unsaturated acids predominate (77%) over saturated (23%). Me an concentration of fatty acids is similar to 680 mg/L in both juices. Separation and quantification of the lipid classes point out that neu tral acylglycerols and polar phosphatides are much more abundant than glycolipids. Significant differences of fatty acid distribution have b een found in the isolated fractions, but each class exhibits similar p rofiles both in NFC and in RFC juices, indicating that no selective de gradation of any acid occurs during the process of thermal evaporation . Linear discriminant analysis of fatty acid concentrations, relative to 90 Italian orange juices taken from the literature, allows blood an d blond juices to be differentiated and oleic, palmitoleic, and linole nic acids to be selected as the most predictive variables. Moreover, p almitoleic, palmitic, and linolenic acids differentiate the bloodjuice s (Tarocco, Sanguinello, and Moro) and linoleic, oleic, and palmitolei c acids the blond juices (Naveline, Ovale, and Valencia).