Nutrients, antioxidants, and antioxidant activity of organically and conventionally grown raspberries


  • K. Skupien
  • I. Ochmian
  • J. Grajkowski
  • E. Krzywy-Gawrońska


The fruits of 'Polka', 'Polana' and 'Pokusa' raspberries grown either under organic practice (ORG) or conventional system (CON) and originating from different locations were evaluated for the content of dry weight, soluble solids, acidity, total sugar, vitamin C, phenolics, and antioxidant activity towards DPPH radicals. Soluble solids varied from 8.3% (CON-'Pokusa') to 10.9% (CON-'Polana'2). Total sugar for organic raspberries was 4.78-6.31 g/100 g, while for conventional group 4.60-7.58 g/100 g. Titratable acidity ranged from 1.67 (CON-'Polana'2) to 2.36 g citric acid/100 g (ECO-'Polana'1). For majority of raspberries vitamin C amounted 20.5-25.6 mg/100 g and only ORG-'Polana'1 showed 17.6 mg/100 g. The scope of total phenol (GAE) in each group was quite similar and overall range was 186.9-249.2 mg/100 g. Antioxidant activity towards DPPH radical was 28.8-45.1% of inhibition for conventionally grown raspberries and 29.0-41.1% for organic fruits. Total anthocyanin content amounted 28.1-48.1 mg/100 g in ORG-group and 26.7-43.6 for conventional fruits. Sum of quercetin derivatives was higher in ORG-group (1.5-3.4 mg/100 g) compared to 1.3-2.4 mg/100 g for conventionally grown raspberries. The values did not show an unequivocal prevalence of any method, because the response of cultivars within specific site conditions was often more pronounced than the system of cultivation.