On the Mechanisms of Adsorbent Interactions with Haze-Active Proteins and Polyphenols

摘要

Solutions of gliadin and catechin were prepared in pH 4.2 alcoholic buffers. The effects of the hydrogen bond acceptor N,N-dimethylformamide (DMF), the nonpolar solvent dioxane, and sodium chloride (NaCl) on removal of catechin by treatment with polyvinyl polypyrrolidone (PVPP) and on removal of gliadin by silica adsorption were examined. DMF and dioxane greatly inhibited removal of the polyphenol by PVPP, whereas NaCl considerably increased it. It was concluded that PVPP attaches to polyphenols through a combination of hydrogen and hydrophobic bonding. DMF and dioxane also greatly inhibited removal of the protein by silica, whereas NaCl increased it. It was concluded that silica attaches to proteins through a combination of hydrogen and hydrophobic bonding. Poly-sarcosine, like polyproline, has a tertiary amine structure that also forms haze with polyphenols and was removed by silica. The mechanisms of attachment of haze-active constituents to silica and PVPP are similar to those involved in forming protein-polyphenol haze.