In the
systems in the present work, the action of free radicals (e.g., coming
from lipid oxidation), trace metals (mainly iron from myoglobin),
and acid (pH 2) are the most feasible causes of carotenoid degradation.
The higher antioxidant activity of shrimp extract may be
responsible for the higher stability of astaxanthin. Furthermore, in
the shrimp extract astaxanthin is mainly in the form of mono- and
diesters, rather than as free astaxanthin (data not shown), whereas
tomato extract contains lycopene in its free form. The same was
also true for b-carotene in BeC film. The free forms of carotenoids
may be more prone to suffer degradation, and to interact with
proteins, than esterified ones. The antioxidant activity of the films
remained stable throughout storage (p 0.05) (Fig. 4), indicating
that the degradation of carotenoids had a negligible effect on the
films' antioxidant activity. This is probably due to the antioxidant
effect of other antioxidants present in the tomato and shrimp extracts,
but it may also be attributable to the presence of degradation
products with antioxidant activity, as deduced from the stable
behavior of BeC film
In thesystems in the present work, the action of free radicals (e.g., comingfrom lipid oxidation), trace metals (mainly iron from myoglobin),and acid (pH 2) are the most feasible causes of carotenoid degradation.The higher antioxidant activity of shrimp extract may beresponsible for the higher stability of astaxanthin. Furthermore, inthe shrimp extract astaxanthin is mainly in the form of mono- anddiesters, rather than as free astaxanthin (data not shown), whereastomato extract contains lycopene in its free form. The same wasalso true for b-carotene in BeC film. The free forms of carotenoidsmay be more prone to suffer degradation, and to interact withproteins, than esterified ones. The antioxidant activity of the filmsremained stable throughout storage (p 0.05) (Fig. 4), indicatingthat the degradation of carotenoids had a negligible effect on thefilms' antioxidant activity. This is probably due to the antioxidanteffect of other antioxidants present in the tomato and shrimp extracts,but it may also be attributable to the presence of degradationproducts with antioxidant activity, as deduced from the stablebehavior of BeC film
การแปล กรุณารอสักครู่..
