Background and methodology:
It is theorized that plants grown without pesticides could contain higher levels of antioxidants as a result of enhanced synthesis of active phytochemicals produced as a defense against biotic and abiotic stress. This study sought to determine whether organic red oranges (the 'Tarocco' cultivar, also known as blood oranges) have a higher phytochemical content (i.e., phenolics, anthocyanins, and ascorbic acid), total antioxidant activity, and in-vitro bioactivity than red oranges grown under integrated (non-organic) agricultural systems. Total phenolics were measured using Folin Ciocalteau assay, while total anthocyanins and ascorbic acid levels were measured by spectrophotometric and high-performance liquid chromatography analysis, respectively. Total antioxidant activity was measured by the ABTS.+ test.
Findings:
Organically-grown oranges have significantly higher total levels of phenolics, total anthocyanins, and ascorbic acids than corresponding non-organic oranges. The organic orange extracts also had a higher total antioxidant activity than non-organic orange extracts. In addition, the results indicate that red oranges have a strong capacity to inhibit the production of conjugated diene containing lipids and free radicals in rat cardiomyocytes and differentiated Caco-2 cells, respectively. Statistically higher levels of antioxidant activity in both cell models were found in organically grown oranges as compared to those produced by integrated agricultural practices.
Reference:
Tarozzi, A., Hrelia, S., Angeloni, C., Morroni, F., Biagi, P., Guardigli, M., Cantelli-Forti, G., & Hrelia, P. (2006). Antioxidant effectiveness of organically and non-organically grown red oranges in cell culture systems. European Journal of Nutrition45(3): 152-158. Available on-line at: http://dx.doi.org/10.1007/s00394-005-0575-6