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Solid foodstuff supplemented with phenolics from grape: antioxidant properties and correlation with phenolic profiles
Aleksandra Rózek1, Isabel Achaerandio, María Pilar Almajano
1Unitat d'Enologia del CeRTA, Generalitat de Catalunya, Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avenida Països Catalans 26, 43007 Tarragona, Spain.
Journal of Agricultural and Food Chemistry
|June 1, 2007
Summary
Grape phenolics were infused into a model food using osmotic dehydration, significantly boosting its antioxidant capacity. This method enhances food with beneficial compounds found in red grapes.
Area of Science:
- Food Science
- Nutritional Biochemistry
- Food Processing Technologies
Background:
- Phenolic compounds from sources like red grapes possess significant antioxidant properties.
- Enhancing the antioxidant capacity of food products is a key area of food science research.
- Osmotic dehydration is a potential method for incorporating bioactive compounds into solid foods.
Purpose of the Study:
- To evaluate osmotic dehydration as a method for enriching a model food with grape phenolics.
- To increase the antioxidant properties of a solid foodstuff using red grape must.
- To quantify phenolic compounds and assess antioxidant activity in the enriched food.
Main Methods:
- A gel was used as a model foodstuff and subjected to osmotic dehydration using concentrated red grape must.
- Processing time varied up to 24 hours, with osmotic pressure adjusted by diluting the grape must.
- Phenolic compounds were quantified using analytical methods, and antioxidant activity was measured using Trolox equivalent antioxidant activity (TEAC) and ferric reducing antioxidant power (FRAP).
Main Results:
- Low molecular weight phenolics, including hydroxycinnamic acids and flavonols, were successfully transferred from red grape must to the osmo-dehydrated gel.
- The total phenolic content in the enriched gel approached levels found in antioxidant-rich fruits and vegetables.
- The osmo-dehydrated food exhibited a TEAC value three times higher than that of the most potent antioxidant-rich fresh fruit.
- Regression analysis confirmed that individual phenolics significantly correlated with the measured antioxidant capacity.
Conclusions:
- Osmotic dehydration is an effective technique for fortifying solid foods with beneficial grape phenolics.
- This process substantially enhances the antioxidant potential of food products, comparable to or exceeding that of certain fruits and vegetables.
- The study demonstrates a strong link between specific phenolic compounds and the overall antioxidant activity of the enriched food.
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