Sind Bio-Äpfel gesünder?

Viele Verbraucher, die sich beim Kauf von Lebensmitteln für Bioprodukte entscheiden, erhoffen sich davon gesundheitsfördernde Effekte. Allerdings liegen bis heute noch nicht genügend wissenschaftliche Daten vor, um ökologisch und konventionell erzeugte Lebensmittel vergleichend ernährungsphysiologisch bewerten zu können. Am Institut für Ernährungsphysiologie der Bundesforschungsanstalt für Ernährung und Lebensmittel (BfEL) wird zurzeit untersucht, ob sich verschiedene pflanzliche Lebensmittel aus ökologischer und konventioneller Anbauweise hinsichtlich ihres Gehaltes an sekundären Pflanzenstoffen und deren ernährungsphysiologischer Wirkung am Menschen unterscheiden

Three-Year Comparison of the Polyphenol Contents and Antioxidant Capacities in Organically and Conventionally Produced Apples (Malus domestica Bork. Cultivar `Golden Delicious')

The present study was performed to evaluate the polyphenol content and antioxidant capacity of apples (cv. `Golden Delicious') grown under defined organic and conventional conditions. Apples were harvested at five comparable commercial farms over the course of three years (2004−2006). In 2005 and 2006 the antioxidant capacity was 15% higher (p < 0.05) in organically produced apples than in conventionally produced fruits. In 2005 significantly higher polyphenol concentrations were found in the organically grown apples. In 2004 and 2006 no significant differences were observed (2004, 304 ± 68 μg/g organic vs 284 ± 69 μg/g conventional, p = 0.18; 2005, 302 ± 58 μg/g organic vs 253 ± 41 μg/g conventional, p = 0.002; 2006, 402 ± 100 μg/g organic vs 365 ± 58 μg/g conventional, p = 0.17). Year-to-year variations in the antioxidant capacity and the polyphenol content of up to 20% were more significant than the production method found within one year. Finally, flavanols and flavonols were major determinants of the antioxidant capacities in these apples. Overall, the production method had a smaller impact on the variation in the polyphenol content and antioxidant capacity of apples than the yearly climate

Influence of the Production Method on Phytochemical Concentrations in Whole Wheat (Triticum aestivum L.): A Comparative Study

The present study was performed to evaluate the concentrations of phytochemicals (carotenoids and phenolic acids) in wheat varieties grown under comparable organic and conventional conditions over three years as part of a long-term field trial. Phenolic acids of the hydroxybenzoic acid and hydroxycinnamic acid group were quantified by HPLC-DAD after extraction as free, soluble conjugated, and bound forms. Furthermore, the carotenoids lutein and zeaxanthin were determined by HPLC-DAD. There were no statistically significant differences between the two farming systems (sum of carotenoids (microg/g) for 2003, 0.91 +/- 0.55 organic vs 0.96 +/- 0.34 conventional; for 2005, 1.61 +/- 0.22 organic vs 1.33 +/- 0.19 conventional; for 2006, 0.87 +/- 0.33 organic vs 0.83 +/- 0.11 conventional; sum of phenolic acids (microg/g) for 2003, 448.4 +/- 151.1 organic vs 327.3 +/- 232.8 conventional; for 2005, 502.8 +/- 168.3 organic vs 484.4 +/- 111.2 conventional; for 2006, 659.1 +/- 112.5 organic vs 945.9 +/- 353.6 conventional). However, statistically significant year-to-year differences up to 55% were observed. Taken together, these results indicate that climate factors have a greater impact on the phytochemical concentrations in whole wheat than the production method (organic/conventional)

Effect of Consumption of Organically and Conventionally Produced Apples on Antioxidant Activity and DNA Damage in Humans

The present study was performed to compare the effects on antioxidant activity and on DNA damage of organic and conventionally produced apples grown under controlled conditions in human peripheral blood lymphocytes. Six healthy volunteers consumed either organically or conventionally grown apples (Golden Delicious, 1000 g) from two neighboring commercial farms in a double-blinded, randomized, cross-over study. The average content of total identified and quantified polyphenols in the organically and conventionally produced apples was 308 and 321 µg/g fresh weight, respectively. No statistically significant differences in the sum of phenolic compounds or in either of the polyphenol classes were found between the agricultural methods. Consumption of neither organically nor conventionally grown apples caused any changes in antioxidant capacity of low-density lipoproteins (lag time test), endogenous DNA strand breaks, Fpg protein-sensitive sites, or capacity to protect DNA against damage caused by hydrogen peroxide. However, a statistically significant decrease in the levels of endonuclease III sensitive sites and an increased capacity to protect DNA against damage induced by iron chloride were determined 24 h after consumption in both groups of either organic or conventionally grown apples, indicating the similar antigenotoxic potential of both organically and conventionally grown apples

No effect of the farming system (organic/conventional) on the bioavailability of apple (Malus domestica Bork., cultivar Golden Delicious) polyphenols in healthy men: a comparative study

Background The organic food sales have been increasing during the recent years. It has been hypothesised that organically grown fruits are healthier based on their higher content of phytochemicals. However, data on the bioavailability of phytochemicals from organically or conventionally produced plant foods are scarce. Methods Two human intervention studies were performed to compare the bioavailability of polyphenols in healthy men after ingestion of apples from different farming systems. The administered apples were grown organically and conventionally under defined conditions and characterised regarding their polyphenol content and antioxidant capacity. No significant differences in the polyphenol content and the antioxidant capacity from the organic and conventional farming system were observed. Results In the short-term intervention study, six men consumed either organically or conventionally produced apples in a randomized cross-over study. After intake of 1 kg apples, phloretin (C max 13 ± 5 nmol/l, t max 1.7 ± 1.2 h) and coumaric acid (C max 35 ± 12 nmol/l, t max 3.0 ± 0.8 h) plasma concentrations increased significantly (P < 0.0001) in both intervention groups, without differences between the two farming systems. In the long-term intervention study, 43 healthy volunteers consumed organically or conventionally produced apples (500 g/day; 4 weeks) or no apples in a double-blind, randomized intervention study. In this study, 24 h after the last dosing regime, the apple intake did not result in increasing polyphenol concentrations in plasma and urine compared to the control group suggesting no accumulation of apple polyphenols or degradation products in humans. Conclusion Our study suggests that the two farming systems (organic/conventional) do not result in differences in the bioavailability of apple polyphenols