Improving resveratrol bioaccessibility using biopolymer nanoparticles and complexes: impact of protein-carbohydrate maillard conjugation.

The impact of encapsulating resveratrol in biopolymer nanoparticles or biopolymer complexes on its physicochemical stability and bioaccessibility was determined. The biopolymer nanoparticles consisted of a zein core surrounded by a caseinate or caseinate-dextran shell. The biopolymer complexes consisted of resveratrol bound to caseinate or caseinate-dextran. The caseinate-dextran conjugates were formed using the Maillard reaction. Both the biopolymer nanoparticles and complexes protected trans-resveratrol from isomerization when exposed to UV light, with the nanoparticles being more effective. Nanoparticles coated by caseinate-dextran were more stable to aggregation under simulated gastrointestinal conditions than those coated by caseinate, presumably due to greater steric repulsion. The bioaccessibility of resveratrol was enhanced when it was encapsulated in both biopolymer nanoparticles and biopolymer complexes. These results have important implications for the development of effective delivery systems for incorporating lipophilic nutraceuticals into functional foods and beverages.