EFFECT OF HYPOTHERMIA ON THE CONTENT OF SUPEROXIDE ANION- RADICAL AND TBA-REACTIVE SUBSTANCES IN PLANT TISSUES

Abstract

The influence of stressors of different nature changes the state of the prooxidant and antioxidant system. The first and most aggressive active form of Oxygen is the superoxidation radical, the secondary product of free radical lipid peroxidation is malonic dialdehyde (MDA). Hypothermia is a necessary phenomenon for plants of temperate latitudes, and a necessary factor in extending the shelf life of edible vegetative parts of plants. The purpose of the study: to identify changes in the value of prooxidant activity in the tissues of edible parts of agricultural plants under the influence of changes in temperature. Quantitative determination of prooxidants and products of free radical peroxidation was investigated on tissue samples of edible parts of the following plants: Allium cepa L. Allium sativum L., Beta vulgaris L., Capsicum annuum L., Cucumis sativus L., Cucurbita pepo L., Daucus sativus (Hoffm.) Roehl., Lycopersicon esculentum Mill.s.l., Solanum melongena L. Solanum tuberosum L.  The level of superoxide generation was carried out by spectrophotometric HCT test, the level of MDA was determined by reaction with TBA. As a result of the research it was found that the average value of increasing the generation of superoxide during cooling is 30.75%, during freezing - 49.35%, but the difference in the average value of ∆MDA in different types of hypothermia is almost absent (growth is 22.12% during cooling and 23.73% during freezing), which may be due to a powerful system of antioxidant tissue protection. Solanum tuberosum L., Allium sativum L., Beta vulgaris L. are the most resistant, in terms of changes in the prooxidant and antioxidant system to hypothermia; Capsicum annuum L. and Lycopersicon esculentum Mill.s.l. are the least resistant. The generative organs of plants are the least resistant to hypothermia than the vegetative ones. Freezing allows storing plant products for a longer time than refrigeration, however, chilled vegetables retain less prooxidants and products of free radical peroxidation in the tissues.