Formation of some of the components of the chemical composition of apple fruits influenced by environmental factors

Apples are a product rich in nutrients and biologically active substances and a leader in the structure of fruit consumption of Russian people. Consumption of apples significantly contributes to the prevention of many diseases. The nutritional and biological value of apple fruits is determined by their chemical composition. The chemical composition of fruits depends on both varietal characteristics and external environmental factors. The purpose of these studies was to compare some of the biochemical parameters of apple fruits grown in the Central Russia, depending on weather conditions. The content of soluble solids, sugars, organic acids and the sugar-acid index (the ratio of sugar to acid) was studied in the fruits of 15 apple cultivars during the years with different meteorological conditions of the growing season. It was found that the content of soluble solids and sugars in apples is largely influenced by the temperature regime; a greater amount of soluble solids and sugars is accumulated in years with the maximum amount of active temperatures and the minimum amount of precipitation during the growing season (May - August). The acidity and taste of the fruit are more affected by the amount of precipitation and the hydrothermal coefficient in the pre-harvest month. Different responses of cultivars to the temperature and humidity regime of the vegetation period of the studied years were revealed. The highest stability of the trait "content of soluble solids in fruits" (V≤10.0%) is characteristic of the cultivars Vostorg, Zvezda Efira, Moskovskoye Ozherelie, Poezia, Priokskoe, Sinap Orlovsky, Sozvezdie; the trait "sugar content" is characteristic of Antonovka Obyknovennaya, Belarusskoe Sladkoe, Zhilinskoe, Moskovskoye Ozherelie, Osipovskoe, Poezia, Priokskoe, Sinap Orlovsky; "content of organic acids" is characteristic of Zhilinskoe and Maslovskoe.