ARS | Publication request: FRACTION OF ORANGE PEEL PHENOLS AND EVALUATION OF THEIR ANTIOXIDANT LEVELS

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2001
Publication Date: September 1, 2001
Citation: Manthey, J.A. Fractionation of orange peel phenols and evaluation of their antioxidant levels. 222nd National Meeting of American Chemical Society. 2001. Paper No. AGFD0091.

Technical Abstract: Orange peel contains numerous flavonoids, hydroxycinnamates, and related phenolic compounds. Among the flavonoids are several main structural categories, including the flavanone di- and triglycosides, flavone-O- and C-glycosides, and the highly methoxylated flavone aglycones, termed polymethoxylated flavones. The hydroxycinnamates are rich in ferulic and p-coumaric acid esters, along with a small number of sinapic acid conjugates. Numerous miscellaneous phenolic compounds also occur, and tend to be more polar than the flavonoids components. Chromatographic methods were used to isolate these diverse categories of compounds from the concentrated orange peel molasses generated during orange processing. Total amounts of each category (mg per Kg 10 °Brix ultrafiltered molasses) were reported. Total phenolic levels and total reducing potential of each category were determined, as well as the total antioxidant levels. Comparisons were also made between these categories in orange and lemon peel molasses. The results show that several of the main categories of citrus peel phenolics are excellent sources of dietary antioxidants.