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  1. #1
    Join Date
    Jan 2010
    Location
    Alachua County, FL, USA
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    6,859

    Default A New Look on Protein-Polyphenol Complexation during Honey Storage

    A New Look on Protein-Polyphenol Complexation during Honey Storage: Is This a Random or Organized Event with the Help of Dirigent-Like Proteins?
    Honey storage initiates melanoidin formation that involves a cascade of seemingly unguided redox reactions between amino acids/proteins, reducing sugars and polyphenols. In the process, high molecular weight protein-polyphenol complexes are formed, but the mechanism involved remains unknown. The objective of this study was twofold: to determine quantitative and qualitative changes in proteins in honeys stored for prolonged times and in different temperatures and to relate these changes to the formation of protein-polyphenol complexes. Six -month storage decreased the protein content by 46.7% in all tested honeys (t-test, p<0.002) with the rapid reduction occurring during the first three month. The changes in protein levels coincided with alterations in molecular size and net charge of proteins on SDS –PAGE. Electro-blotted proteins reacted with a quinone-specific nitro blue tetrazolium (NBT) on nitrocellulose membranes indicating that quinones derived from oxidized polyphenols formed covalent bonds with proteins. Protein-polyphenol complexes isolated by size-exclusion chromatography differed in size and stoichiometry and fall into two categories: (a) high molecular weight complexes (230–180 kDa) enriched in proteins but possessing a limited reducing activity toward the NBT and (b) lower molecular size complexes (110–85 kDa) enriched in polyphenols but strongly reducing the dye. The variable stoichiometry suggest that the large, “protein-type” complexes were formed by protein cross-linking, while in the smaller, “polyphenol-type” complexes polyphenols were first polymerized prior to protein binding. Quinones preferentially bound a 31 kDa protein which, by the electrospray quadrupole time of flight mass spectrometry (ESI-Qtof-MS) analysis, showed homology to dirigent-like proteins known for assisting in radical coupling and polymerization of phenolic compounds. These findings provide a new look on protein-polyphenol interaction in honey where the reaction of quinones with proteins and polyphenols could possibly be under assumed guidance of dirigent proteins.
    http://www.plosone.org/article/info%...l.pone.0072897
    americasbeekeeper.com
    beekeeper@americasbeekeeper.com

  2. #2
    Join Date
    Apr 2011
    Location
    Elizabethton, Tn
    Posts
    341

    Default Re: A New Look on Protein-Polyphenol Complexation during Honey Storage

    Do we have a translator available? I feel kind of woozy for having read this...
    Last edited by honeyman46408; 09-05-2013 at 04:54 PM. Reason: UNQuote
    It takes a family to raise a family, it takes a village to really screw that up... Djei5

  3. #3
    Join Date
    Aug 2002
    Location
    Nehawka, Nebraska USA
    Posts
    45,889

    Default Re: A New Look on Protein-Polyphenol Complexation during Honey Storage

    In other words, honey is not just simple sugar water...
    Michael Bush bushfarms.com/bees.htm "Everything works if you let it." ThePracticalBeekeeper.com 40y 200h 37yTF

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