Chitin microspheres: A fascinating material with high loading capacity of anthocyanins for colon specific delivery

Colon specific delivery is one promising way to enhance the bioavailability of anthocyanins. Herein, chitin microspheres with average diameter of 80 gm fabricated via a new way were found to load anthocyanins with predicted capacity based on Langmuir isotherm as much as 2718 54 mg/g under the optimal condition of pH 4, which is the largest amount ever reported. Electrostatic interaction, hydrogen bonding and hydrophobic interactions were proved to be the main driving forces for the load of anthocyanins by chitin microspheres. Moreover, less than 30% of the loaded anthocyanins were released under the investigated pH range from 1.2 to 6 because of the strong interaction between chitin micro spheres and anthocyanins. Finally, it was found about 40% of the loaded anthocyanins was released in the simulated gastrointestinal tract for chitin microspheres. Moreover, after coating the anthocyanins loaded chitin microspheres with a layer of ethyl cellulose, more than 85% loaded anthocyanins were delivered to the colon. All the results revealed that new chitin microspheres were promising carriers for colon specific delivery of bioactive compounds. This work demonstrated an effective new way to utilize original chitin, which is abundant but less researched in the field of food science. (C) 2016 Elsevier Ltd. All rights reserved.