Influence of agrotechnical factors on variance of qualitative and quantitative composition of phenolic compounds in apples.

The aim of the research: to determine the influence of different agrotechnical factors on variance of qualitative and quantitative composition of the phenolic compounds in apple samples and to assess the antioxidant activity of their extracts in vitro. The objectives of the research: 1. To evaluate the effect of competitive tension of fruit trees on the qualitative and quantitative composition of phenolic compounds in apple samples and to assess the antioxidant activity of their extracts in vitro. 2. To evaluate the effect of geographical apple-tree location on the qualitative and quantitative composition of phenolic compounds in apple samples and to assess antioxidant activity of their extracts in vitro. 3. To evaluate the effect of apple-tree growth regulation on the qualitative and quantitative composition of phenolic compounds in apple samples and to assess antioxidant activity of their extracts in vitro. 4. To evaluate the effect of mechanized pruning of apple-tree on the qualitative and quantitative composition of phenolic compounds in apple samples and to assess antioxidant activity of their extracts in vitro. 5. To evaluate the effect of fruit location in the canopy on the qualitative and quantitative composition of phenolic compounds in apple samples and to assess antioxidant activity of their extracts in vitro. The results and conclusions of the research. The highest total amount of phenolic compounds (6,044±0,233 mg/g) was detected in apple fruits grown at a density of 3 × 1,00 m. In the lowest density grown apple-tree fruits accumulated the highest amount of flavan-3-ols. The highest total amount of phenolic compounds (4,862±0,056 mg/g) was detected in apples grown in Estonia, the lowest amount (1,701±0,075 mg/g) was detected in apples grown in Poland. There was detected a tendentious increase of phenolic compounds to the north-east direction. In the study of the effect of fruit tree growth regulation, the lowest total amount of phenolic compounds (2,210±0,063 mg/g) was detected in the fruit of apples sprayed with prohexadione-calcium once. The highest total amount of phenolic compounds (3,368±0,104 mg/g) and significantly higher levels of flavan-3-ols were detected in the fruits of mechanically on both sides pruned apple-trees. The highest total amount of phenolic compounds (2,580±0,132 mg/g) was detected in apples picked from the eastern side of the crown, the lowest amount (1,914±0,311 mg/g) was detected in apples picked from the upper part of the crown