"The present study demonstrates that cyclodextrins can be used as resveratrol complexation agent, to increase total resveratrol concentration in aqueous solution," wrote lead author Carmen Lucas-Abellan from the Universidad Catolica San Antonio de Murcia.
Interest in reservatrol has been increasing with various studies reporting linking the polyphenol to lower incidence of coronary heart disease, and possible possessing anti-cancer activity.
However, the polyphenol is said to be sensitive to light, air and oxidative enzymes, which raise questions about its bioavailability, formulation and manipulation in functional foods.
"Given resveratrols many health-promoting activities, it is necessary to develop a method for increasing its bioavailability and stability," said the researchers.
The researchers behind the new study looked at the potential of resveratrol to be encapsulated in beta-cyclodextrins, a chemically and physically stable polysaccharide produced by the enzymatic modification of starch.
Some cyclodextins are already used as carriers for natural colours, flavours and vitamins, solubilisers of lipids, stabilisers of oil in water emulsions, or flavour or aroma modifiers in a variety of processed foods.
Writing in the journal Food Chemistry, the Spanish researchers investigated the formation of resveratrol-cyclodextrin inclusion complexes in aqueous solutions and analysed the stability of these complexes in the presence of lipoxygenase enzymes, which catalyse the oxidation (degradation) of the polyphenol.
Lucas-Abellan and her co-workers report that addition of cyclodextrins inhibited the resveratrol oxidation by lipoxygenase, compared to a system that contained free resveratrol.
"The delay in the resveratrol oxidation was caused by its entrapment in the internal cavity of cyclodextrins, which act as substrate reservoir in a dosage-controlled manner," said the researchers.
The research is in-line with the current trend of food manufacturers to turn to encapsulation technologies as a way of achieving much-needed differentiation and enhancing product value. Tapping into key and emerging consumer trends with innovative techniques is becoming increasingly important for food manufacturers.
Additional research is necessary, however, to further examine if such complexes are sensitive to temperature or pH, which may limit their applicability to food and/or beverages.
Source: Food Chemistry Published on-line ahead of print; doi: 10.1016/j.foodchem.2006.10.068 "Cyclodextrins as resveratrol carrier system" Authors: C. Lucas-Abellan, I. Fortea, J.M. Lopez-Nicolas and E. Nunez-Delicado