In vitro estimation of iron and zinc dialysability from vegetables and composite dishes commonly consumed in Italy: effect of red wine

Selected vegetables (artichoke, asparagus, broccoli, cauliflower, cabbage, kale, carrot, potato), and some composite dishes (macaroni with vegetables) were analysed for their in vitro iron and zinc dialysability. The effect of red wine on iron dialysability from broccoli, potatoes and their respective composite dishes was also studied. Iron dialysability ranged from 10.7 to 23%, artichokes and asparagus showed lower values (5.7 and 7.7%, respectively). Zinc dialysability ranged from 19.5 to 49.3%. The generally high iron dialysability might be ascribed to organic acids (ascorbic, citric, malic acid). The addition of macaroni to vegetables drastically lowered both iron and zinc dialysability (from 40 to 75%). This effect was dependent on phytate content of macaroni (about 192 mg per dish). A negative relationship between red wine and iron dialysability was found. The decrease in iron dialysability was 45% in broccoli and 70% in macaroni with broccoli, 25% in potatoes and 46% in macaroni with potatoes. Present findings indicate that vegetables may contribute to get a useful level of absorbable iron and zinc in the diet.