Interactions among Food Chemicals
Introduction
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
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
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
Flavonoid-carbohydrate Interaction
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
Flavonoid-carbohydrate Interaction
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
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
Questions?

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