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Thermal stability of  polyphenols

Thermal stability of  polyphenols. P21 Lina Glittmann Juan Sesma Martín. Polyphenols. Definition Polyphenols are a group of chemicals found in plants characterized  by the presence of more than one phenol group  per molecule. Properties

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Thermal stability of  polyphenols

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  1. Thermalstability of polyphenols P21 Lina Glittmann Juan Sesma Martín

  2. Polyphenols • Definition Polyphenols are a group of chemicals found in plants characterized by the presence of more than one phenol group per molecule. • Properties Polyphenolshave beneficial propertiesfor human

  3. Types of polyphenols

  4. Heatreatments • Drying • Dehydration • Enzymaticreaction

  5. General effects • t>80°C  reduction of phenolic compounds • Leaching • Begin of thermal degradation - forming of monomers - reaction among molecules - hydrolysis - oxidation • without thermal treatment amount to enzymatical reactions

  6. Effectsrelatedtoproperties • Epimerization frequency  stabilisation • High Polimerization degree  degradation • presence of gallate groups  heat sensitivity • Biological activity  degradation through enzymes • Hydrolysis  Stabilization

  7. Effect of polyphenols on heat stability • Preventthermaldegradation of more sensible compounds • polymeric • Temperaturearound 30-55 ̊C • Copigmentationeffect • Oxidationtoquinins • Interactionwithproteins

  8. Kinetics • Degradation instantly in the first 10min • zero order • Velocity constant k increasing with T Time for complete disappearance of total polyphenols kiso values as a function of temperature in extra-virgin oil

  9. Conclusion • Changes in • Phenolicprofil • Chemical- • Physical- • Biological Properties • Inactivationofenzymsnecessary

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