Distribution of metals and phenolic compounds as a criterion to evaluate variety of berries and related jams

Polyphenols, anthocyanins, phosphate, iron, zinc, manganese, calcium, potassium, magnesium and sodium were evaluated both in berries belonging to the genera Rubus and Ribes and in related jams by means of spectrophotometric techniques, to verify a possible differentiation on the basis of these parameters. The phenolic and anthocyanins higher contents were detected for black currant fruits and jams. Regarding the total phenolic content, in 11 cases it is possible to observe a higher content in jams with respect to the related row fruits. All samples contain a high amount of potassium, calcium and magnesium but small quantities of sodium. Phosphate is abundant especially in currants. As regard jams all results about metals are lower than those obtained for fruits, this is due to the dilution during the preparation of the jams. Multivariate statistical analysis shows that on the basis of obtained analytical results it is possible differentiate not only fruit but also the derived jams. (c) 2005 Elsevier Ltd. All rights reserved.