Volume 17
Issue 4
Horticulture
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Available Online: http://www.ejpau.media.pl/volume17/issue4/abs-08.html
CHANGES IN POLYPHENOL AND ANTHOCYANIN CONTENT AND ANTIOXIDANT ACTIVITY IN METHANOL AND WATER EXTRACTS PREPARED FROM STORED DRIED WRINKLED ROSE (ROSA RUGOSA THUNB.) PETALS
Agnieszka Zawi¶lak, Magdalena Michalczyk
Department of Refrigeration and Food Concentrates, University of Agriculture in Kraków, Poland
ABSTRACT
The aim of the present study was to follow changes in the content of total
polyphenols and anthocyanins as well as antioxidant activity in methanol and
water extracts prepared from dried wrinkled rose (Rosa rugosa) petals
stored for a year at 21 ± 1ºC. Polyphenols were evaluated
by Folin-Ciocalteau assay and anthocyanins were determined by the pH-differential
method. Antioxidant properties were assayed by DPPH radical scavenging activity
and by measuring the reducing power of both extracts. The extracts were a rich
and stable source of polyphenols (800–1300 mg/100 g) and anthocyanins (85–150
mg/100 g). Extract antioxidant activity expressed as EC50 value did
not change significantly during storage of dry material and was quite
high (0.9–1.5 g/g DPPH). Reducing power was strongly correlated with EC50 (r = -0.86,
p < 0.01). The antioxidant power of both extracts correlated more closely with polyphenol content than with anthocyanins. Extracts of methanol showed better antioxidant properties
than those of water, probably due to higher polyphenol and anthocyanin content.
Key words: Rosa rugosa, dried petals, polyphenols, anthocyanins, antioxidant activity.
Agnieszka Zawi¶lak
Department of Refrigeration and Food Concentrates, University of Agriculture in Kraków, Poland
Phone: +48 12 662 48 09
ul. Balicka 122
30-149 Kraków
Poland
email: a.zawislak@ur.krakow.pl
Magdalena Michalczyk
Department of Refrigeration and Food Concentrates, University of Agriculture in Kraków, Poland
ul. Balicka 122
30-149 Kraków
Poland
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