Bread enriched with resveratrol: Influence of the delivery vehicles on its bioactivity

Trans-resveratrol (RSV) is recognised as a bioactive ingredient in the development of functional foods. Its stability, solubility, and bioavailability constraints can be overcome by delivery systems, not yet tested in foods. This study aims at evaluating the impact of two delivery systems on the stability, antioxidant activity, bio-accessibility and bioavailability of RSV integrated into a bread matrix: an inclusion complex of RSV and gamma-cyclodextrin (gamma CD.RSV) and RSV loaded zein nanoparticles (nZ-RSV). Wheat bread was supplemented with 0.5% of pure RSV (RSV-bread) and equivalent amounts of gamma-CD.RSV and nZ-RSV. The amount of RSV recovered from the hydroethanolic extracts of gamma-CD.RSV- and nZ-RSV-bread was 70.3% and 62.8% of the initial amount, respectively, lower than RSV-bread extract, 89.0%, indicating lower degradability during bread preparation. Both vehicles helped to retain RSV antioxidant activity but did not increase RSV bioaccessibility (c.a. 40% for free RSV and gamma CD.RSV, and 29% for nZ-RSV). In vitro tests on intestinal cell monolayers showed that, after 4 h of contact, only 5.0% of the initially available amount of RSV was able to permeate the intestinal barrier in all samples. Thus, bread itself is a vehicle for RSV integration into our daily diet, without the need for an additional delivery system.

Automated summary

This study evaluated the impact of two delivery systems on the stability, antioxidant activity, bio-accessibility, and bioavailability of trans-resveratrol integrated into a bread matrix. The results showed that bread itself can effectively deliver trans-resveratrol without the need for additional delivery systems.