title: Cyclodextrin inclusion complex formation and solid-state characterization of the natural antioxidants alpha-tocopherol and quercetin.
abstract: Cyclodextrin (CD) complexation procedures are relatively simple processes, but these techniques often require very specific conditions for each individual guest molecule. Variations of the coprecipitation from aqueous solution technique were optimized for the CD complexation of the natural antioxidants alpha-tocopherol and quercetin. Solid inclusion complex products of alpha-tocopherol/beta-CD and quercetin/gamma-CD had molar ratios of 1.7:1, which were equivalent to 18.1% (w/w) alpha-tocopherol and 13.0% (w/w) quercetin. The molar reactant ratios of CD/antioxidant were optimized at 8:1 to improve the yield of complexation. The product yields of alpha-tocopherol/beta-CD and quercetin/gamma-CD complexes from their individual reactants were calculated as 24 and 21% (w/w), respectively. ATR/FT-IR, 13C CP/MAS NMR, TGA, and DSC provided evidence of antioxidant interaction with CD at the molecular level, which indicated true CD inclusion complexation in the solid state. Natural antioxidant/CD inclusion complexes may serve as novel additives in controlled-release active packaging to extend the oxidative stability of foods.
authors.affiliation: Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Koontz
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Marcy
authors.forename: Sean F
authors.initials: SF
authors.lastname: O'Keefe
authors.forename: Susan E
authors.initials: SE
authors.lastname: Duncan
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D011232:Chemical Precipitation; D003505:Cyclodextrins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D011794:Quercetin / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D024502:alpha-Tocopherol / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry; D047408:gamma-Cyclodextrins / Q000737:chemistry
chemical_list: D000975:Antioxidants; D003505:Cyclodextrins; D047392:beta-Cyclodextrins; D047408:gamma-Cyclodextrins; D011794:Quercetin; D024502:alpha-Tocopherol; C031215:betadex; C023792:gamma-cyclodextrin