Discovery and Characterization of Carotenoid-Oxygen Copolymers in Fruits and Vegetables with Potential Health Benefits

J Agric Food Chem. 2016 May 18;64(19):3767-77. doi: 10.1021/acs.jafc.6b00503. Epub 2016 May 6.

Abstract

We reported previously that the spontaneous oxidation of β-carotene and other carotenoids proceeds predominantly by formation of carotenoid-oxygen copolymers and that β-carotene copolymers exhibit immunological activity, including priming innate immune function and limiting inflammatory processes. Oxidative loss of carotenoids in fruits and vegetables occurs during processing. Here we report evidence for the occurrence of associated analogous copolymer compounds. Geronic acid, an indirect, low molecular weight marker of β-carotene oxidation at ∼2% of β-carotene copolymers, is found to occur in common fresh or dried foods, including carrots, tomatoes, sweet potatoes, paprika, rosehips, seaweeds, and alfalfa, at levels encompassing an approximately thousand-fold range, from low ng/g in fresh foods to μg/g in dried foods. Copolymers isolated from several dried foods reach mg/g levels: comparable to initial carotenoid levels. In vivo biological activity of supplemental β-carotene copolymers has been previously documented at μg/g levels, suggesting that some foods could have related activity.

Keywords: carotenoid oxidation; carotenoid-oxygen copolymers; geronic acid; non-vitamin A immunomodulation; oxidative polymerization; provitamin A.

MeSH terms

  • Carotenoids / chemistry*
  • Chromatography, Gel
  • Fruit / chemistry*
  • Gas Chromatography-Mass Spectrometry
  • Oxygen / chemistry*
  • Polymers / chemistry*
  • Vegetables / chemistry*

Substances

  • Polymers
  • Carotenoids
  • Oxygen