Structural properties of food proteins underlying stability or susceptibility to human gastrointestinal digestion

Is any specific structural trait that makes food proteins resistant or sensitive to proteolytic degradation in the gastrointestinal tract? In principle, elements at various hierarchical levels of protein structure may confer stability or susceptibility to hydrolysis. However, based on a critical revision of the recent literature, we emphasize the impossibility of providing absolute answers because protein digestion is affected by a complex series of factors ascribable to the food micro-/macrostructure and the intricacy of human digestion. Taking into consideration the uncertainty associated with the current in vitro models of food digestion/absorption and the capability offered by recent analytical advancements, we emphasize the need for suitable in vivo readouts for improving the comprehension of the fate of dietary proteins in our body and their effects on human health.