1. Improvement of antioxidant activity in food by impregnation
Project Thesis
Ph.D. Student: Aleksandra Różek
Supervisor: Dra Montserrat Ferrando
Universitat Rovira i Virgili

2. Outline Main goals of the project Identification of focus area
Principle of osmotic treatment
Applications of OT
Plan of the project
Primary results
Future plans

3. Main goals
Estimate the osmotic treatment as a technique to impregnate solid foodstuff with polyphenols obtained as a by-product from the wine industry
Establish the conditions for the impregnation with polyphenols; in order to increase the antioxidant activity
Evaluate the effect of enrichment in polyphenols on the antioxidant capacity of the end product
Determine the effect of impregnation on the microstructure of the food considering the localization of polyphenols

4. 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

5. Why wine industry ?
The grape skins contain the highest concentration of polyphenols, which are potent antioxidants
The effect of different wine antioxidant polyphenols (catechin, epicatechin, quercetin, and resveratrol)
Easy to obtain skins and seeds of the grape with high amount of polyphenols

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

7. Principle of osmotic treatment
Tissue
Sucrose solution
Water
Solutes
Soluble components

8. Industrial applications of OT
COMBINED TREATMENTS
UNIT OPERATION
SOLUTION MANAGEMENT
fruit, vegetables
meat
fish
Recycled solution
OSMOTIC
TREATMENT
RECYCLING/
CONCENTRATION
Concentrated/
Impregnated product
Diluted solution
FREEZING
PASTEURIZATION
FREEZE DRYING
MICROWAVE
DRYING
CONVECTIVE
DRYING
Curriculum vitae

9. PLAN OF THE PROJECT Determination of OT conditions in agar-agar cubes
Determination of OT conditions in fruit cubes
Water loss
Mass loss
SOLID GAIN
Concentration of sucrose solution
Time of the process
Water activity
Impregnation of polyphenols in agar-agar gel cubes & fruit

10. Results of OT (agar-agar gel)
Mass transfer
-12 -2 8 18 28 2 4 6 10
Time [h]
[%]
Water loss
Solid Gain
Mass loss
WL(mean)
SG(mean)
ML(mean)

11. PLAN OF THE PROJECT
Characterization of polyphenols obtained from the grape pomace
Extraction conditions:
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

12. Acknowledgements: Universitat Rovira i Virgili for financial support
Dra Montserrat Ferrando

13. Thank You Questions …