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United States Department of Agriculture

Agricultural Research Service

Research Project: Investigation of Biological Activities and Metabolism of Citrus Phytochemicals

Location: Citrus and Other Subtropical Products Research

2011 Annual Report


1a.Objectives (from AD-416)
1. Measure in vivo pharmacokinetics and biological actions of citrus phytonutrients in human and small-animal trials. 2. Study factors that influence the in vivo pharmacokinetics of citrus phytonutrients. 3. Characterize the beneficial actions of citrus phytonutrients in in vivo systems.


1b.Approach (from AD-416)
1. Administer citrus juices to test subjects and to monitor targeted biological actions and the presence of these compounds or their metabolites in biological sample extracts, primarily of blood and urine, over set periods of time. 2. Extract phytonutrients and main metabolites from biological tissue extracts, and analyze by high performance liquid chromatography-mass spectrometry (HPLC-MS).


3.Progress Report

This project is related to Objective 1: Identify and characterize biologically active compounds in citrus peel and associated processing byproducts for potential as value-added products to promote human health.

There is interest in the evaluation of differences in phytonutrient bioavailabilities between freshly squeezed and commercially prepared orange juice. The Brazilian cooperator designed pharmacokinetic studies to monitor uptake rates and extents of the major flavonoid in orange juice, hesperidin. Freshly squeezed and commercially prepared juices from identical sources of oranges were prepared, and phytochemical compositions were compared by analytical techniques. Freshly squeezed orange juice was found to contain much higher nobiletin and tangeretin and other peel oil constituents. Differences in total flavonoid contents were also observed. Preparations were made for future animal feeding trials.

Progress was monitored by e-mail, exchange of equipment, and phone conversations.


Last Modified: 9/10/2014
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