Improvement of antioxidant activity in food by impregnation

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Improvement of antioxidant activity in food by
impregnation

• Project Thesis
• Ph.D. Student Aleksandra Rózek
• Supervisor Dra Montserrat Ferrando
• Universitat Rovira i Virgili

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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

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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

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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 ?

• 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

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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.

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Principle of osmotic treatment
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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
MICROWAVE DRYING
FREEZE DRYING
CONVECTIVE DRYING
Curriculum vitae
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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
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Results of OT (agar-agar gel)
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PLAN OF THE PROJECT

• Characterization of polyphenols obtained from the
  grape pomace

Extraction conditions

• Total amount of polyphenols Foulin-
  Ciocalteus method
• Type of polyphenols - HPLC
• Antioxidant activity TEAC method

Impregnation of polyphenols in agar-agar gel
cubes fruit
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Acknowledgements

• Universitat Rovira i Virgili for financial
  support
• Dra Montserrat Ferrando

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Thank YouQuestions