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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Commodity Utilization Research » Research » Publications at this Location » Publication #343249
Research Project: Developing Technologies that Enable Growth and Profitability in the Commercial Conversion of Sugarcane, Sweet Sorghum, and Energy Beets into Sugar, Advanced Biofuels, and Bioproducts

Location: Commodity Utilization Research

Title: Formation of polyphenol-denatured protein flocs in alcohol beverages sweetened with refined cane sugars

Author
item Eggleston, Gillian
item Triplett, Alexa

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2017
Publication Date: 10/10/2017
Citation: Eggleston, G., Triplett, A. 2017. Formation of polyphenol-denatured protein flocs in alcohol beverages sweetened with refined cane sugars. Journal of Agricultural and Food Chemistry. 65:9703-9714.

Interpretive Summary: The sporadic appearance of floc from refined, white cane sugars in alcohol beverages remains a technical problem for both beverage manufacturers and sugar refiners. Strong relationships existed between the haze floc and indirect measures of polyphenolic and flavonoid colorants and protein content of the invert sugars. Ethanol induced denaturation of the protein exposed hydrophobic polyphenol binding sites that were further exposed when heated to 80 °C. A tentative mechanism for floc formation was advanced.

Technical Abstract: The sporadic appearance of floc from refined, white cane sugars in alcohol beverages remains a technical problem for both beverage manufacturers and sugar refiners. Cane invert sugars mixed with 60% pure alcohol and water, increased light scattering by up to ~1000-fold. Insoluble and soluble starch, fat, inorganic ash, oligosaccharides, Brix, and pH were not involved in the prevailing floc formation mechanism. Strong polynomial correlations existed between the haze floc and indicator values I.V. (color at 420 nm pH 9.0/color at pH 4.0 - an indirect measure of polyphenolic and flavonoid colorants) (R2=0.815) and protein (R2=0.819) content of the invert sugars. Ethanol induced denaturation of the protein exposed hydrophobic polyphenol binding sites that were further exposed when heated to 80 °C. A tentative mechanism for floc formation was advanced by molecular probing with a haze (floc) active protein and polyphenol, as well as polar, non-polar, and ionic solvents.