How does meat cooking affect the speed of protein digestion?

It has been shown that the speed of digestion of food proteins determines the efficiency of their assimilation. For the elderly, this is a limiting factor for the stimulation of post-prandial anabolism. Meat plays a central role to limit sarcopenia in the elderly thanks to its concentration of proteins and its potentially high digestion kinetics. But, Cooking, in particular, affects the macro and microstructure of meat proteins and little information is available about the impact of thermal treatments on nutritional potential.

We tested three temperatures corresponding to rare, medium rare and well-done meats (55, 70 and 90°C) and identified the hydrolysis kinetics of meat proteins according to their location.
We showed that meat cooking affects the kinetics of protein digestion throughout the digestive tract. We established a complete database of 1743 peptides obtained from 71 meat proteins under different cooking conditions and quantified each of the associated peptides and proteins using high-resolution mass spectrometry and the “label free” method. Meat cooking influences the digestion of meat proteins according to their location in the muscle cell. In the gastric compartment, sarcoplasmic proteins are more hydrolysed when the meat is cooked at low temperatures (55°C). On the other hand, when the meat is cooked medium rare or well done (70°C, 90°C), the sarcoplasmic proteins are less degraded in the gastric compartment, probably due to the heat-induced denaturation of proteins. This study also highlighted how peptidomic tools based on mass spectrometry analysis provide new insights into food proteins digested in the gastrointestinal tract. This study will eventually lead to the design of foods with an ad hoc structure to modulate digestion in the gastrointestinal tract using specific processes.

In the future, the oral phase, i.e., chewing the meat, will be implemented in partnership with the Human Nutrition Unit and the dental school, with a specific population targeted: seniors. In addition, the peptidomic database published here provides relevant information for the international community that can be used to determine, for example, all possible bioactive sequences using in silico tools.