Effect of Milk on Antioxidant Capacity and Anthocyanin
in the Strawberry Beverages. In the present study,
we observed reduced antioxidant capacity when freeze-dried
strawberry powder was formulated in a beverage with dairy
ingredient (nonfat dry milk powder). Additionally, reduced
levels of anthocyanins in the milk-based beverage compared to
the water-based beverage were observed, suggesting the
possibility of secondary complex formation between polyphenols
and milk proteins. It is also possible that polyphenols−
protein complexes are retained during the filtration step when
samples are prepared for analysis. Zulueta et al. observed that
adding milk to orange juice significantly decrease the in vitro
antioxidant capacity of the juice (measured by TEAC).27 Arts et
al. demonstrated an interaction between flavonoids and
proteins with associated changes in antioxidant capacity in
vitro.28 Polyphenolic compounds possess a high binding affinity
for proteins.29 On the basis of the previous research and
observed findings in the present study, we suspect that changes
in antioxidant capacity and concentration of phenolic
compounds in strawberry−dairy beverages are possibly due to
phenolic (tannin)−protein interactions. The significance of
these interactions on biological activity remains to be
determined. In an in vivo study with blueberries consumed
with and without milk, reduced plasma concentrations of
phenolic acids (caffeic and ferulic acid) were reported when
milk was consumed with the berries, suggesting interference
with bioavailability of some phenolic compounds and, possibly,
in vivo biological effects.10
Effect of Storage on the Antioxidant Capacity and
Anthocyanins in the Strawberry Beverages. Fresh
strawberries have a short shelf life, mostly due to their high
water content and the incidence of microbial load (molds and
yeasts). In the present study, the shelf life of strawberry-based
beverages after conventional HTST and HPP processing was
evaluated on the basis of antioxidant capacity and microbiological
end points. At the end of 5 weeks under refrigerated
conditions, significantly lower values of ORAC and FRAP were
recorded compared to week 0 (P < 0.05) with declines that
initiated during week 2, which may be attributed to residual
Effect of Milk on Antioxidant Capacity and Anthocyanin
in the Strawberry Beverages. In the present study,
we observed reduced antioxidant capacity when freeze-dried
strawberry powder was formulated in a beverage with dairy
ingredient (nonfat dry milk powder). Additionally, reduced
levels of anthocyanins in the milk-based beverage compared to
the water-based beverage were observed, suggesting the
possibility of secondary complex formation between polyphenols
and milk proteins. It is also possible that polyphenols−
protein complexes are retained during the filtration step when
samples are prepared for analysis. Zulueta et al. observed that
adding milk to orange juice significantly decrease the in vitro
antioxidant capacity of the juice (measured by TEAC).27 Arts et
al. demonstrated an interaction between flavonoids and
proteins with associated changes in antioxidant capacity in
vitro.28 Polyphenolic compounds possess a high binding affinity
for proteins.29 On the basis of the previous research and
observed findings in the present study, we suspect that changes
in antioxidant capacity and concentration of phenolic
compounds in strawberry−dairy beverages are possibly due to
phenolic (tannin)−protein interactions. The significance of
these interactions on biological activity remains to be
determined. In an in vivo study with blueberries consumed
with and without milk, reduced plasma concentrations of
phenolic acids (caffeic and ferulic acid) were reported when
milk was consumed with the berries, suggesting interference
with bioavailability of some phenolic compounds and, possibly,
in vivo biological effects.10
Effect of Storage on the Antioxidant Capacity and
Anthocyanins in the Strawberry Beverages. Fresh
strawberries have a short shelf life, mostly due to their high
water content and the incidence of microbial load (molds and
yeasts). In the present study, the shelf life of strawberry-based
beverages after conventional HTST and HPP processing was
evaluated on the basis of antioxidant capacity and microbiological
end points. At the end of 5 weeks under refrigerated
conditions, significantly lower values of ORAC and FRAP were
recorded compared to week 0 (P < 0.05) with declines that
initiated during week 2, which may be attributed to residual
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