Antioxidant activity of apples--an impact of maturity stage and fruit part.
BACKGROUND
Recently, many studies have been oriented towards improving methods and efficiency of antioxidants recovery from different fruit and their wastes.The aim of the study was to evaluate antioxidant potential of apple seeds and peel, which constitute the fruit industry wastes, and compare it to apple flesh. Antioxidant activity of apples at different maturity and storage stage were analysed too.


METHODS
The Idared and the Šampion cultivars of apples were used in the study. Antioxidant activity was estimated using ABTS and DPPH assays, and polyphenols profile was determined by HPLC method.


RESULTS
Seeds of analysed apple cultivars were characterised by a significantly higher antioxidant capacity and by higher concentrations of polyphenols analysed when compared to their peel and flesh. There were present two predominant compounds: phloridzin in seeds (84% and 72%) and quercetin glycosides in peels (54% and 38%, Idared and Šampion cultivars, respectively). No quercetin glycosides in seeds were found. The capacity to scavenge an ABTS radical, but not DPPH, decreased during ripening of apples, while cold storage resulted in enhanced antioxidant potential.


CONCLUSIONS
It can be concluded that unripe apples together with apple seeds and peel (fruit industry wastes) constitute a valuable source of polyphenols.
Department of Fermentation Technology and Technical Microbiology, University of Agriculture in Krakow, Cracow, Poland. aduda-chodak@ar.krakow.pl
Aleksandra
A
Duda-Chodak
Tomasz
T
Tarko
Tadeusz
T
Tuszyński
D000975:Antioxidants / Q000032:analysis*; D052160:Benzothiazoles / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry*; D027845:Malus / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis*; D059808:Polyphenols / Q000032:analysis; D012639:Seeds / Q000737:chemistry; D013451:Sulfonic Acids / Q000032:analysis
D000975:Antioxidants; D052160:Benzothiazoles; D010936:Plant Extracts; D059808:Polyphenols; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid