Texture changes and protein hydrolysis in different cheeses under simulated gastric environment

The structure of food plays an important role in determining rate of digestion by influencing the disintegration rate and affecting the release of bioaccessible components. In the stomach, breakdown of food structure occurs through mechanical peristaltic forces and hydrolysis of macronutrients. The objective of this study was to investigate the gastric digestion of Cheddar, Mozzarella, and Parmesan cheeses using both static soaking method and dynamic in vitro gastric digestion model. During static soaking in simulated gastric juice, cheeses had less texture softening at lower pH. Mozzarella cheese showed texture hardening behavior, leading to the lowest rate of nutrient leaching among the three cheeses, while Parmesan cheese had the highest rate of nutrient leaching. During dynamic gastric simulation, Mozzarella cheese showed the most resistance to protein hydrolysis by generating only 6.81 g/L amino acids when compared to 12.70 g/L and 24.3 g/L amino acids released by Cheddar and Parmesan cheese, respectively. The resistance of Mozzarella cheese was attributed to the dense outside layer formed due to aggregation of the protein matrix at highly acidic environment that encapsulated the cheese particles and prevented gastric juice from further digesting the proteins.