Abstract:

The antioxidant capacities of ethanolic extracts from six different varieties of red raspberry pomace in Northeast
China were evaluated. Results showed that the highest contents of total phenols, flavonoids and proanthocyanidins were
determined in red raspberry pomace extracts from the U.S. Raspberry variety, which were up to 14.18, 3.71, and 15.28 mg/g,
respectively. The highest content (0.68 mg/g) of anthocyanins was detected in Heritage red raspberry pomace extracts.
The total reducing capacities of pomace extracts from the Fertod Zamatos variety and wild red raspberry were close to that
of VC. Pomace extracts from all varieties except Heritage had stronger scavenging capacities against DPPH and ABTS+
radicals than VC. The results of correlation analysis showed that there were significant correlations between the contents of
flavonoids or proanthocyanidins and total reducing capacity, between the contents of proanthocyanidins or anthocyanins and
DPPH scavenging capacity, and between the contents of total phenols or flavonoids and ABTS+ radical scavenging capacity
in red raspberry pomace extracts. The results of this study implied that red raspberry pomace extracts from the Fertod
Zamatos variety and wild red raspberry have stronger antioxidant activities.

Key words: red raspberry pomace, extracts, active components, antioxidant capacities