The gustatory properties of fruits, especially the sweet taste, are due to the differences not only in the sugar content, but also in other substances, primarily organic acids. Along with sugars, organic acids are substances used intensively in the biochemical reactions characteristic of metabolic processes, a fact that leads to the decrease of the energy value of the fruits and to the modification of their taste. In this context, the storage technologies applied aim to ensure measures to slow down the processes that stimulate the oxidation of biochemical compounds, in order to maintain the quality of the fruit. The purpose of this study was to evaluate the post-harvest influence of the Fitomag preparation on the change in the titratable acidity value of apple fruits, grown under the conditions of the Republic of Moldova.