Photo-protection and controlled release of folic acid using edible alginate/chitosan nanolaminates

The formation, characterization, photo-protective properties and release profiles of folic acid-loaded nanolaminated films were investigated by UV-visible spectroscopy, FTIR, Raman and SEM microscopy. Food-grade alginate/chitosan nanolaminates were obtained by the layer-by-layer technique and folic acid (FA) was incorporated by post-diffusion. The FA concentration of loading solutions and immersion time significantly affected the FA content in nanolaminates. The maximum FA loading was reached using FA solutions at 10 mg/mL for 30 min (54.4 mu g/cm(2)), or 12.5 mg/mL for 120 min (approximate to 70 mu g/cm(2)). Nanolaminates containing FA were more stable under ultraviolet light exposure than non-encapsulated FA. The rate and concentration of FA released from nanolaminates were greater at buffer pH 7 than at pH 3, which might play a key role in the delivery and bioavailability of nutraceuticals. These results provide important information for the design of nanolaminates containing hydrophilic active compounds for food applications. (C) 2017 Elsevier Ltd. All rights reserved.