4. Conclusion
The addition of complex food matrix to chokeberry juice immediately
decreased total phenolic content, DPPH scavenging capacity
as well as total reducing power of chokeberry juice during in vitro
stimulated digestion. Only ferrous chelating capacity exhibited
higher values in digested fractions than in the initial juice, which
could be explained by the release of peptides from food matrix
which possess strong metal chelating features. The contents of
individual anthocyanins are also affected by both digestion and
addition of complex food matrix, and their content decreased by
approximately 90%. In vitro digestion slightly elevated total phenolic
content, DPPH scavenging activity and reducing power compared
to digestion control, although all parameters were still
lower than in the initial juice. Based on obtained results it can be
speculated that binding of phenolic compounds to food matrix
combined with prolonged exposure to mild acid environment during
intestinal digestion as a result of feeding conditions could allow
the transport intact phenolic compounds to colon. Furthermore,
our data showed that chokeberry juice digested in the presence
of food matrix possessed antiproliferative capacity and markedly
reduced proliferative rate of Caco-2 cells. Bearing in mind the limitations
of in vitro assays, as well as precautions in interpretation of
obtained results, our overall conclusion is that although gastrointestinal
digestion combined with the presence of complex food
matrix affects chokeberry juice polyphenols they still possess significant
antioxidant and antiproliferative capacity.