Influence of natural conditions of southern Dagestan on formation of food substances in fruits of Golden Delises apples

Abstract

The results of studying the amino acid composition, macroand microelements, vitamins and other food substances in Golden Delicious apples grown in terroirs located at various altitudes above sea level in the south of Dagestan are presented in order to determine cultivation sites with natural conditions contributing to the greatest accumulation of these valuable components in fruits. The elemental composition of apples was studied using flame and atomic absorption photometry, mass concentrations of amino acids by HPLC methods, the content of sugars, titrated acids, pectins and vitamin C – titrimetrically, phenols and vitamin P colorimetrically. It was found that natural factors of the fruit zone located on the plain cause a high concentration of sugars in Golden Delicious apples – 11,3 %, soluble dry substances – 14,9 % and minerals: potassium (135.5 mg%), calcium (19.0 mg%), sodium (25.6 mg%), magnesium (12.6 mg%) and iodine (2.4 μg%), and the climatic conditions of the foothills are favorable for the synthesis of titrated acids (0,51%), vitamins C (6,8 mg %) and P (63,1 mg %), phenolic (362,1 mg %) and pectin substances (0,83 %), as well as iron, zinc and copper. The difference in the formation of minerals in apples, depending on natural conditions and the altitude gradient of the place of growth, was: for potassium – 7,2; sodium – 8,2; calcium – 9,5; magnesium – 9,4; iron – 10,9; copper – 10,2; zinc – 9,3, iodine – 8,3 %. The total amount of amino acids in apples, depending on the culture site, ranged from 683,2 to 696,9 mg/dm3. In fruits from the foothills, the total mass concentrations of replaceable and essential amino acids were 1,3 and 5,9% higher, respectively, than in apples grown on the plain. The results of the study can be taken into account in the rational use of agroecological resources of fruit zones that differ in soil-climatic conditions and altitude gradient, as well as to reveal the biological potential of the Golden Delicious apple variety.