Release profiles of beef myofibril protein-bound heterocyclic amines and effects of dietary components on in vitro digestion.

The release profiles of protein-bound heterocyclic amines (HAs) in beef myofibril protein (MP) model systems were investigated after different enzyme dosage or stages of digestion were simulated in vitro. The effects of co-digestion of pepper, apple, and onion with bound HAs on the release rate of bound HAs were also explored. The results showed that, at a constant ratio of substrate to enzyme, the bound HAs were not completely converted into free HAs. Most bound HAs were enzymatically released after intestinal digestion, resulting in a significant increase of free HAs. β-Carbolines were more easily hydrolyzed compared with other HAs. Pepper, apple, and onion promoted the release of bound HAs, and the total free HAs was increased 20.44, 41.56, and 33.28 times by 1.0% pepper, 150% apple, and 150% onion. The sensitivity of HAs to different additives was variable, with the most significant changes observed in harman and norharman.