Recent advances in the formation of protein-bound heterocyclic aromatic amines and their transformation during digestion: A comprehensive review

Background

Heterocyclic aromatic amines (HAAs) widely present in meat when it undergoes thermal processing. It has been reported that HAAs exist mainly in free and bound forms. Protein-bound HAAs can be enzymatically converted to free forms during digestion, potentially enhancing human exposure to these harmful compounds. However, the current study mainly focuses on free HAAs, and there are few reports on the formation of protein-bound HAAs and their transformation during digestion.

Scope and approach

This review summarizes the possible reaction mechanisms during the formation of protein-bound HAAs, generalizes the transformation of protein-bound HAAs in the digestive process, and further elaborates the effects of dietary components such as chili peppers, onions, Angelica dahurica (AD), apples on the formation of protein-bound HAAs and their transformation in the digestive process.

Key findings and conclusions

There are three main pathways for the formation of protein-bound HAAs: (1) Proteins directly react with other precursors of HAAs; (2) Free HAAs react with proteins to form stable amide bonds; (3) Free HAAs selectively adsorb onto the surface of protein polymers. Most protein-bound HAAs are enzymatically released during intestinal digestion. In addition, polyphenols and amide compounds in dietary components promote the release of protein-bound HAAs during digestion, while AD polysaccharides have an inhibitory effect on the conversion of protein-bound HAAs. This review provides new ideas for finding new strategies to inhibit the formation of protein-bound HAAs during food processing, as well as theoretical basis for controlling the release of protein-bound HAAs during digestion.