A Comparison of In Vitro Bioavailability of Total Antioxidant Capacity of Selected Organic and Conventional Vegetables
In vitro bioavailability of vegetables
Keywords:Freeze dry, Solvent optimization, FRAP Method, percent recovery of antioxidants
The objective of the study is to know if there is a difference in in vitro bioavailability (also known as in vitro digestibility) of organically and conventionally cultivated vegetables with respect to antioxidant capacity. A method that simulates human digestive system was used to study the in vitro bioavailability of antioxidants present in organically grown and conventionally grown vegetables. Four commonly consumed vegetables namely spinach, tomato, beetroot and carrot were selected for the study. Institute of Marketlogy Organic Certification (I.M.O) certified organic vegetables and conventional vegetables grown in the same soil and agro climatic condition were selected for the study. The vegetables were freeze dried using Lyodryer and stored at 4°C±2 in dark. Four different solvents were used for extraction to identify the best solvent for each vegetable. Total antioxidant capacity was estimated by Ferric Reducing Antioxidant Power (FRAP) method as described by Benzie and Strain (1996). In vitro bioavailability was determined according to a method described by Luten et al (1996). The percent recovery was studied based on the difference between antioxidant capacity of vegetables before and after in vitro digestion. The results indicate that among the vegetables studied, antioxidants in conventional beetroot had the highest recovery after digestion.
The recovery of antioxidant capacity after digestion is slightly better for conventional vegetables compared to organic vegetables in case of spinach, beetroot and tomato whereas there was no significant difference in the in vitro bioavailability of organic and conventional carrot.
Argyari, K., Komatis, M., and Kapsokefalou, M. 2006. Iron decreases the antioxidant capacity of red wine under conditions of in vitro digestion. Food Chemistry. 96:281–289.
Benzie, I.F. and Strain, J.J. 1996. The ferric reducing ability of plasma as a measure of “Antioxidant Power” the FRAP assay. Analytical Biochemistry. 239:70–76.
Carl, K.W. and Sarah, D. 2006. Organic foods: concise reviews in food science. Journal of Food Science. 71(9):117–124.
Granado-Lorencio, F., Olmedilla-Alonso, B., Herrero-Barbudo, C. Blanco-Navarro, I., Pérez-Sacristán, B., and Blázquez-García, S. 2007. In vitro bioaccessibility of carotenoids and tocopherols from fruits and vegetables. Food Chemistry. 103(3):641–648.
IFOAM. International Federation of Organic Agricultural Movements, Basic Standards for Organic Production and Processing, General Assembly, Argentina, November 1998. https://www.ifoam.org/en/about-us-1. Retrived December 26, 2017.
Luten, J., Crews, H., Flynn, A., Dael, P. V., Kastenmayer, P., Hurrell, R., Deelstra, H., Shen, Li-Hua. Tait, F. S., Hickson, K., Farre, R., Schlemmer, U. and Frohlich, W. 1996. Interlaboratory trial on the determination of the in vitro iron dialyzability from food. Journal of the Science of Food and Agriculture. 72:415–424.
McDougall, G. J., Fyffe, S., Dobson, P. and Stewart, D. 2005. Anthocyanins from red wine-their stability under simulated gastrointestinal digestion. Phytochemistry. 66:2540–2548.
Perez-Vicente, A., Gil-Izquierdo, A. and Garcia-Viguera, C. 2002. In vitro gastrointestinal digestion study of pomegranate juice, phenolic compounds, Anthocyanins and vitamin C. Journal of Agriculture and Food Chemistry. 50:2308–2312