Oxidation and subsequant protein aggregation, caused by the cooking process of meat, can lead to conformational changes in the meat that can lower the digestibilty of the protein in meat by digestive enzymes (4) from 94% to 90% (5).
The conformational changes are due oxidised sulfer containing amino acids (e.g cystiene). Oxidation and aggregation can lead to the reduced bioavailability of amino acids such as cysteine; adequate cysteine intake is crucial to healthy hair.
The decrease of meat protein digestibility by cooking processes may not only reduce the bioavailability of indispensable amino acids but also increase the quantity of protein that reaches the large intestine to be femented by bacteria in the colon.
Periodically, the fermentaion of these proteins leads to the release of harmful metabolites such as ammonia, hydrogen disulfide and phenolic compounds.
These metabolites have a negatove impact on the mucosa of the colon (6)(7)(8). This impact is thought to be involved in the potential role of preocessed and red meat intake in the risk of corectal cancer (9)(10)(11). The relationship between ccooked meat and colon cancer has been hotly debated (12).
Cooking meat at a high temperature for a long time tends to result in an additional 1 gram of proteins reaching the colon for an intake of 25–30 grams of protein from meat (13).