Vitamin protection by Alginate-Whey Protein Micro Gel (AL-WPC MG) as a novel microcapsule against gastrointestinal condition; case study: B-complex vitamins.

The aim of the current research was to identify and develop an ideal delivery system in order to protect the vitamin from gastrointestinal conditions. For this purpose, vitamin loaded Alginate-Whey protein micro gels (AL-WPC MGs) developed as a biopolymer carrier. This microcapsule was examined in terms of morphology, ζ-potential particle size and distribution, encapsulation and delivery efficiency, and in vitro gastric and intestinal digestions. Absorbance method was used to monitor B-complex vitamins release over time at the simulated gastrointestinal conditions. Release experiments illustrated beneficial attributes for these microspheres. Release mechanism was predicted by using various kinetic equations. Results indicated that the most of the fabricated spherical shaped AL-WPC MGs was under 100 μm in size, and these microcapsules had an excellent and moderate stability in gastric and intestinal conditions, respectively. It was found that the highest vitamin release rate occurs in the simulated gastric-intestinal situation, and type of the vitamin had a slight effect on the release rate and release profile. Kinetic models suggested that release from group B vitamins mainly was controlled by Fickian diffusion mechanism. In general, this research showed that the AL-WPC MGs protect the vitamin from gastric digestion and could be used as a delivery system. In previous works, a  novel AL-WP MGs and use for different active agent encapsulation was developed, while the final purpose of this work was to study the vitamin release mechanism from AL-WPC MGs at the gastro–intestinal situation. Accordingly, this microcapsule showed the highest vitamin release rate at the simulated intestinal situation. This high release could be due to instability of alginate in neutral pH, and also enzymatic digestion of whey protein. The better release of vitamin at intestinal condition is desirable to achieve the nutrient effect during food consumption. This micro gel therefore appears to be potentially beneficial as digestion delivery vehicles for bioactive compounds in the food and nutraceuticals industry as well as non-food industry.