Improvement of Improvement of antioxidant activity in antioxidant activity in food by impregnationfood by impregnation

Project ThesisPh.D. Student: Aleksandra RóżekPh.D. Student: Aleksandra Różek

Supervisor: Dra Montserrat FerrandoSupervisor: Dra Montserrat Ferrando

Universitat Rovira i VirgiliUniversitat Rovira i Virgili

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OutlineOutline

Main goals of the projectMain goals of the project

Identification of focus areaIdentification of focus area

Principle of osmotic treatmentPrinciple of osmotic treatment

Applications of OTApplications of OT

Plan of the projectPlan of the project

Primary resultsPrimary results

Future plansFuture plans

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Main goalsMain goals

Estimate the osmotic treatment as a technique to impregnate solid Estimate the osmotic treatment as a technique to impregnate solid foodstuff with polyphenols obtained as a by-product from the wine foodstuff with polyphenols obtained as a by-product from the wine industryindustry

Establish the conditions for the impregnation with polyphenols; in Establish the conditions for the impregnation with polyphenols; in order to increase the antioxidant activityorder to increase the antioxidant activity

Evaluate the effect of enrichment in polyphenols on the antioxidant Evaluate the effect of enrichment in polyphenols on the antioxidant capacity of the end productcapacity of the end product

Determine the effect of impregnation on the microstructure of the Determine the effect of impregnation on the microstructure of the food considering the localization of polyphenolsfood considering the localization of polyphenols

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Why polyphenols ?Why polyphenols ?

ATHEROSCLEROSIS

ANTIMICROBIAL ACTIVITY

CANCER (inhibit the proliferation of human

prostate cancer cell lines)

OXIDATIVE STRESS FROM PASSIVE SMOKING

SKIN DAMAGE AND PHOTOPROTECTION

REGULATE BLOOD PRESSURE

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Why wine industry ?Why wine industry ?

The grape skins contain the highest concentration The grape skins contain the highest concentration of polyphenols, which are potent antioxidantsof polyphenols, which are potent antioxidants

The effect of different wine antioxidant The effect of different wine antioxidant polyphenols (catechin, epicatechin, quercetin, and polyphenols (catechin, epicatechin, quercetin, and resveratrol)resveratrol)

Easy to obtain skins and seeds of the grape with Easy to obtain skins and seeds of the grape with high amount of polyphenolshigh amount of polyphenols

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Why osmotic treatmentWhy osmotic treatment ? ?

Fruit and vegetables dried contain more soluble Fruit and vegetables dried contain more soluble substances than untreated onessubstances than untreated onesDried fruits are light in colour and thus sulphiting is Dried fruits are light in colour and thus sulphiting is needless.needless.Small changes in colour, taste and aroma Small changes in colour, taste and aroma Part of the low molecular weight organic acids are Part of the low molecular weight organic acids are lost but only a small loss of flavour compounds is lost but only a small loss of flavour compounds is observedobservedFood have better texture and less shrinkage compared Food have better texture and less shrinkage compared to traditionally dried products.to traditionally dried products.

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Principle of osmotic treatmentPrinciple of osmotic treatment

Tissue

Sucrose solution

Water

Solutes

Soluble components

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Industrial applicationsIndustrial applications of OT of OT

MICROWAVEDRYING

FREEZE DRYING

PASTEURIZATION

Curriculum vitae

Concentrated/Impregnated product

fruit, vegetables

meatfish

Recycled solution

Diluted solution

COMBINED TREATMENTS UNIT OPERATION SOLUTION MANAGEMENT

OSMOTIC TREATMENT

FREEZING

CONVECTIVEDRYING

RECYCLING/CONCENTRATION

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Determination of OT conditions in agar-agar cubes

PLAN OF THE PROJECTPLAN OF THE PROJECT

Impregnation of polyphenols in agar-agar gel cubes & fruit

- Water loss

- Mass loss

- SOLID GAIN

Determination of OT conditions in fruit cubes

-Concentration of sucrose solution

-Time of the process

-Water activity

1010

Results of OT (agar-agar gel)Results of OT (agar-agar gel)

Mass transfer

-12

-2

8

18

28

0 2 4 6 8 10

Time [h]

[%]

Water loss Solid Gain Mass loss

WL(mean) SG(mean) ML(mean)

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PLAN OF THE PROJECTPLAN OF THE PROJECTCharacterization of polyphenols obtained from the grape pomace

- Total amount of polyphenols – Foulin- Ciocalteu‘s method

- Type of polyphenols - HPLC

- Antioxidant activity – TEAC method

Impregnation of polyphenols in agar-agar gel cubes & fruit

Extraction conditions:

1212

Acknowledgements:Acknowledgements:

Universitat Rovira i Virgili for financial Universitat Rovira i Virgili for financial supportsupport

Dra Montserrat FerrandoDra Montserrat Ferrando

1313

Thank YouThank YouQuestions …Questions …