Research on the mineral composition of cultivated and wild blueberries and cranberries
Institute of Biology, University of Latvia, Laboratory of Plant Mineral Nutrition, Miera street 3, Salaspils, LV-2169 Salaspils municipality, Latvia
European cranberry (Vaccinium oxycoccos L.) and European bilberry (Vaccinium myrtillus L.) are among the most popular wild-harvested fruits in Latvia, traditionally used in folk-medicine and food. The commercial cultivation of American cranberry (Vaccinium macrocarpon Ait.) and highbush blueberry (Vaccinium corymbosum L.) was successfully started during last 20 years. With a berry production increase due to considerable hectarage of plantings and growing consumer interest in health-improving foods cultivated blueberries and cranberries have found a place in a daily intake as an excellent source of phenolic and nutritive compounds, vitamins and minerals. As the chemical composition of Vaccinium spp. has an important implication on human health, detailed information on the nutritional content of berries are of special importance. The aim of this study was to compare the contents of twelve biologically essential elements (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B) in berries of four Vaccinium species: cultivated and wild blueberries (Vaccinium corymbosum and Vaccinium myrtillus) and cranberries (Vaccinium macrocarpon and Vaccinium oxycoccus). Together 136 (leaf and berry) samples were collected from 7 main cranberry and blueberry producing sites and 17 native woodland areas and bogs in Latvia. A comparison of wild and cultivated species showed similar concentrations for the macroelements K, Ca and S in cranberry and N, P in blueberry fruits. While statistically significant differences were found for N, P and Mg in case of cranberries and Ca, K, Mg and S for blueberries. The research revealed statistically significant differences of most micronutrients in cultivated and wild berries. Plant leaf and fruit analysis revealed the organ-specific distribution of mineral elements in all species studied. In most of the cases, leaf analysis supported concentration differences in fruits.