P21
Lina Glittmann
Juan Sesma Martín

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Definition
Polyphenols are a group of chemicals found in plants characterized by the presence of more than one phenol group per molecule.
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Properties
Polyphenols have beneficial properties for human

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Drying
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Dehydration
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Enzymatic reaction

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 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

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

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Prevent thermal degradation of more sensible compounds polymeric
Temperature around 30-55 ̊C
Copigmentation effect
Oxidation to quinins
Interaction with proteins

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

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Changes in
 Phenolic profil
 Chemical-
 Physical-
 Biological Properties
Inactivation of enzyms necessary