Total antioxidant activity of “pH 3.5 MIX-es”
The determination of the total antioxidant activity of beetroot
juice mixed with fruit based acidity regulators to obtain final pH of
about 3.5 was carried out by spectrophotometric batch test
employing ABTSþ radical. Reference samples were also prepared
by mixing beetroot juice with water or water with the fruit juices in
corresponding proportions (Table 1). These solutions served as
controls of the input of individual diluted components into antioxidant
potential of the respective mixtures. This allowed to
recognize whether the tested fruit based regulators contained antioxidants
that act synergistically with beetroot components e
increasing, or antagonistically - lowering the antioxidant activity of
the mixture, compared to the additive effect. The latter occurs
when antioxidant activity is equal to the sum of determined activities
for the individual components.
The total antioxidant activities of the “pH 3.5 MIX-es” are shown
in Table 3. The most commonly used acidity regulator, i.e. citric acid,
did not display a positive influence on antioxidative potential of the
respective “pH 3.5 MIX”. Only after two weeks' storage, it seemed to