The effects of organic and conventional farm management and harvest time on the polyphenol content in different raspberry cultivars.

Raspberry fruits are a perfect source of polyphenols, including flavonols, anthocyanins. Some experiments have indicated that organic fruits contain more bioactive compounds than conventional fruits. The aim of this study was therefore to analyse and compare the concentration of bioactive compounds in organic vs. conventional raspberries and to determine the effects of harvest time and cultivar. Three cultivars of raspberry ('Laszka', 'Glen Ample' and 'Glen Fine') that were harvested in summer and one 'Polka' cv. that was harvested in autumn time from organic and conventional cultivation methods were used in the experiment. The contents of dry matter and polyphenols in the fruits were determined. The organic samples contained significantly more dry matter, phenolic acid and flavonoids, including myrycetin, quercetin, luteolin and quercetin-3-O-rutinoside. Harvest time was an important factor in raspberry fruit quality.