Abstract:

In order to construct edible conveying carriers with excellent controlled release properties,soy protein /κ-carrageenan mixed cold-set gels were produced via the crosslinking of microbial transglutaminase ( MTGase) . Then,the microstructure and rheological properties of the mixed gels were analyzed,and the tablets flaked by the gels via the freeze-drying were used as the controlled release carriers for riboflavin to investigate the release properties and the release dynamics in simulated gastrointestinal fluid. The results show that ( 1) the mixed gels are structurally in dense network; ( 2) κ-carrageenan improves the strength and hardness of the mixed gels,while riboflavin weakens the gel properties; ( 3) in simulated gastrointestinal condition,the one-hour accumulative release rate of the gels and the tablets for riboflavin in simulated gastric fluid is lower than 17% but ranges from 75% to 100% after a moving to simulated intestinal fluid for 9h,which means that both the gels and the tablets have sustained release
effect for riboflavin. In addition,it is found that the release mechanisms of riboflavin in simulated gastric and intestinal fluids are different from each other; specifically,one is controlled by Fick diffusion while the other is by non-Fick diffusion.

Key words: soy protein, κ-carrageenan, mixed cold-set gel, tablet, ribof lavin, controlled release