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United States Department of Agriculture

Agricultural Research Service

Title: Intrinsic Labeling of Plants for Nutrient Bioavailability Studies

item Caulfield, Frances
item Beecher, Gary

Submitted to: Advances in Experimental Medicine and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 20, 2001
Publication Date: January 20, 2003
Citation: Novotny Dura, J., Britz, S.J., Caulfield, F.A., Beecher, G.R., Clevidence, B.A. 2003. Intrinsic labeling of plants for nutrient bioavailability studies. Advances in Experimental Medicine and Biology.537:131-140.

Interpretive Summary: Fruits and vegetables which are high in beta-carotene and other carotenoids are associated with promotion of health and decreased risk of many diseases. However, the availability of these nutrients from fruits and vegetables is affected by the plant structure and other compounds present in the plant. It is crucial that the availability of carotenoids and other nutrients from plants be known so that health professional can make appropriate recommendations for nutrient intakes. The difficulty in studying nutrient availability in plants rests in the difficulty in discerning newly eaten nutrients from those already present in the body. The present study describes a novel technique for measuring nutrient availability from green, leafy vegetables. The technique involves labeling all the nutrients in the vegetable with a stable (safe) isotope called carbon-13. Since carbon-13 is uncommon in nature, the nutrients which are absorbed after eating a carbon-13 vegetable can be detected in the blood. Without the carbon-13 tag, the nutrients mix with those already in the body pool, and it is very difficult to measure nutrient absorption. The present study describes a first attempt at this method. Kale was successfully grown in a carbon-13 environment, and beta-carotene was subsequently analyzed for carbon-13 accumulation. It was found that 99% of carbon atoms associated with beta-carotene from the kale were carbon-13. Therefore, we have shown that nutrients in green, leafy vegetables can be fully tagged with carbon-13 for nutrition studies. These results will be useful for scientist whose research is aimed at evaluating availability of nutrients from plant foods.

Technical Abstract:

Last Modified: 7/28/2014
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