VARIATIONS IN THE PHENOLIC COMPOSITION OF FRUIT JUICES WITH DIFFERENTTREATMENTS

In this work we have determined the variations in the composition of p henolic compounds of natural peach and apple juice with different ther mal and enzymatic treatments. The following phenolic compounds were id entified and quantified in samples of treated and untreated fruit juic es: cinnamic acids (caffeic, p-coumaric and ferulic acids), cinnamic d erivatives (chlorogenic and p-coumarylquinic acids and feruloylglucose ), flavonols (quercetin glycosides), dihydrochalcones (phloretin glyco sides), flavan-3-ols [(+)-catechin and (-)-epicatechin], and procyanid ins (dimer B-2, trimer C-1 and tetramer T-4) Furfural derivatives, com pounds widely used as indicators of prior thermal treatment, were also studied using these samples, The results indicate that the different processes tested gave rise to a series of changes in composition that may make it possible to identify the type of treatment employed on the basis of the composition of phenolic compounds in the fruit juices.