Total Antioxidant Activity of Amaranth Leaves in Оntogenesis

The authors carried out in the fieldwork with a new variety of amaranth «Lipetsky». In order to identify qualitative and quantitative laws of manifestation of the total antioxidant activity of amaranth the leaves were collected in different phases of plant vegetation, dehydrated in mild conditions of air-shadow drying and subsequently dried under harsh conditions 105º C to a constant mass of samples. Testing of plant samples was carried out using a coulometric method of titration (author's method) of free bromine radicals generated in the aquatic environment by plant titrant (water extract dried in the shade at a temperature of 22º±3°C of leaves). It was examined the combined samples of 10 samples of plant leaves of different tiers and of different ages with field plot of 10 ha. Biometric averages of plants during the growing season: growth, the weight of plants, number of leaves, the weight of leaves, stem and inflorescence of the plant are given. This shows the dynamics of total antioxidant activity of leaves of amaranth during the growing season. The thermal stability of the total antioxidant activity (TAA) for combined extracts of 10 samples of leaves of different ages and from different parts of plants when they are drying at 105°C was tested. The dynamics of change, TAA aqueous extracts of the dried amaranth samples with different stages of the growing season corresponds to the previously identified trends in the availability of high quantitative values in the phase of mass budding beginning of flowering and minima in the initial growth phases (3-8 leaves) and ripening of seed for different varieties of amaranth. There were revealed the increase in antioxidant activity upon drying amaranth samples at 105°C, revealed a new type of qualitative dynamics of TAA, while vegetation with a characteristic quantitative changes by more than 50% for the beginning of the growth phase (the first phase of 3-8 leaves) and the final phase of seed maturation.