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

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

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

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

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

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.

Principle of osmotic treatment Tissue Sucrose solution Water Solutes Soluble components

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

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

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)

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

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

Thank You Questions …