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Interactions among Food Chemicals

Interactions among Food Chemicals. —— Non-covalent Interaction between Flavonoids and Macronutrients. Jiyang Fang. Introduction. Flavonoids. Plant-derived polyphenolic compounds C6-C3-C6 backbone Dispersed in fruits, vegetables and beverages Against chronic and degenerative diseases

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Interactions among Food Chemicals

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  1. Interactions among Food Chemicals ——Non-covalent Interaction between Flavonoids and Macronutrients Jiyang Fang

  2. Introduction Flavonoids • Plant-derived polyphenolic compounds • C6-C3-C6 backbone • Dispersed in fruits, vegetables and beverages • Against chronic and degenerative diseases • Pigments (copigmentation) • Intra and inter-flavonoid interactions Covalent interaction • Chemical reactions between functional groups Non-covalent interaction • Protein, carbohydrate, lipid

  3. Flavonoid-protein Interaction Specific binding • Defined globular tertiary structure • digestive enzymes Non-specific binding • Non-globular proteins • salivary proline-rich proteins (PRPs) • albumin-type proteins Van de Waals type • Hydrogen binding • London interactions • Ionic interactions Schematic representation of the interaction between polarizable non-polar groups involving flavonoids through dispersive van der Waals interactions (p-stacking) and the role of the surrounding hydrogen-bond network.

  4. Flavonoid-protein Interaction Competitive binding • Flavonoids+Salivary proline-rich proteins (PRPs)=Oral astringency • Addition of milk (whey protein and casein) Haze formation • Aggregation/precipitation • Hydrolysis of protein/removal of flavonoids Enhance flavonoid stability and antioxidant capacity • Reduce auto-oxidative degradative reactions Carrier (flavonoid) • Limit protein digestibility

  5. Flavonoid-carbohydrate Interaction Starch Gelatinization and retrogradation • Plasticizers to bind amylose chains by hydrogen bonds Starch digestibility and nutritional properties (glucose) • Gut digestive enzyme and glucose transporter • Starch modification Non-Starch polysaccharides Primary forces • Non-specific hydrogen bonding • Ionic interaction

  6. Flavonoid-carbohydrate Interaction Non-Starch polysaccharides Dietary fiber • Polyphenol carrier Disrupt insoluble flavonoid-protein complex • Prevent the formation of insoluble tannin-protein complex • Water-soluble protein-polyphenol-polysaccharide complex • Compete directly with proteins Haze formation • Non-desirable insoluble complex Polysaccharide particles • Quercetin entrapped in chitosan complex by ionic interaction

  7. Flavonoid-lipid Interaction Emulsifier • Hydrophobic-hydrophilic interface Natural antioxidants • Enrich for better stability of oil towards oxidation Hydrophobic interaction • Cell-membrane lipid bilayers and liposomes • Membrane physical properties, like permeability • Protecting effect of flavonoids against oxidation

  8. Questions?

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