By Stephen Daniells, Nutra Ingredients USA
Nano-scale emulsions may protect resveratrol from being metabolized in the gut and enhance the absorption of the compound in the intestine, suggests new research.
Soy lecithin and sugar ester-based nano-emulsions were found to resist metabolism in a lab model of digestion, and to produce the highest antioxidant activities in cells, according to results published in the Journal of Agricultural and Food Chemistry.
“The present study serves as a useful model for developing delivery systems of nutraceutical and functional food ingredients that are stable, efficient, and highly bioavailable,” wrote researchers from the University of Salerno in Italy and Guelph Food Research Centre in Canada.
Resveratrol’s rosy potential
Resveratrol is often touted as the bioactive compound in grapes and red wine, and has particularly been associated with the so-called 'French Paradox'. The phrase, coined in 1992 by Dr Serge Renaud from Bordeaux University, describes the low incidence of heart disease and obesity among the French, despite their relatively high-fat diet and levels of wine consumption.
The potential health benefits of the compound include anti-cancer effects, anti-inflammatory effects, cardiovascular benefits, anti-diabetes potential, energy endurance enhancement, and protection against Alzheimer’s.
Interest in the molecule is increasing. At the recent SupplySide East show in New Jersey Datamonitor’s Tom Verhile told attendees: “New food and beverage product launches containing resveratrol tripled in 2009-2010. This is an ingredient to watch…”
The new study examined if the potential of nanoemulsions to encapsulate resveratrol, something the researchers note has “never been reported before” due to “formulation, stability, and cell absorption” issues.
Using a technique called high-pressure homogenization, the researchers encapsulated resveratrol in peanut oil-in-water emulsions with an average particle size of around 250 nanometers when soy lecithin was used.
The emulsions were then tested in a lab model of the intestine, being first exposed to saliva, and then a lowering of the pH, and subsequent exposure to select enzymes like pepsin.
“The digestion process did not significantly affect the cellular antioxidant activity of encapsulated resveratrol, suggesting its being stable after gastric and intestinal digestion and available to be absorbed by the cells in its active antioxidant form,” wrote the researchers.
“The most physically and chemically stable formulations also exhibited the highest chemical and cellular antioxidant activity, which was comparable to that of the undigested and unencapsulated resveratrol dissolved in [the solvent] DMSO,” they added.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, doi: 10.1021/jf2031346
“Evaluation of the Stability and Antioxidant Activity of Nanoencapsulated Resveratrol during in Vitro Digestion”
Authors: M. Sessa, R. Tsao, R. Liu, G. Ferrari, F. Donsi