Abstract
Changes in mineral contents of different portions of apple fruit during development were investigated using Fuji apples grown in an experimental orchard of Morioka Branch, Fruit Tree Research Station in 1980. Apples were sampled from June 13 (3 weeks after petal fall) to November 13 (25 weeks after petal fall, harvest time) at an interval of two weeks. Fruits were separated to peel, pulp, core and seed immediately after picking and determined nine minerals viz. Na, K, Mg, Ca, Fe, Mn, Cu, Zn and P. Concentration of all mineral components on fresh weight basis decreased through fruit development period in pulp tissue, but the aspects of the changes were different among minerals. Na, K, Fe, Cu and P concentrations decreased relatively sharp until 5 week after petal fall, and then remained constant until harvest. Mg, Ca and Mn decreased till 11 weeks after petal fall and then were unchanged. Zn concentration decreased through the developing period. Each content of the minerals in pulp tissue of a whole fruit increased during fruit development. Na, K, Fe, Cu and P increased relatively great and Mg, Ca and Mn increased relatively moderate. The effect of fungicide application (Bordeaux mixture including copper) on the concentration of Cu was observed only in peel, but not in pulp and others. Fluctuation in the mineral concentrations in the fruit between trees used in the experiment was also observed especially great in Fe, Mn, Cu and Zn. It seemed to be due to the different growing conditions nevertheless grown in the same orchard. It is suggested that we need to consider the fluctuation in mineral contents in apples especially in minor elements when we use the values of the Standard Tables of Food Composition in Japan.
