text: Aside from measuring the concentration of protein in meat, calculating bioavailability is another way in determining the total amount of component and quality. The calculation is done when food molecules are digested in various steps. Since human digestion is very complicated, a wide range of analytical techniques are used to obtain the data, including foodomics protocol and an in vitro static simulation of digestion.
  The procedure is divided into 3 stages as the samples are collected from oral, gastric and duodenal digestion in order to study protein digestibility closely and thoroughly. A meat based food, Bresaola, is evaluated because beef muscles are still intact, which can be used to indicate nutritional value.
  The consequences of oral step can be observed at the beginning of the gastric digestion, the first stage. As there is no enzymatic proteolytic activity at this stage, the level of H-NMR, a spectrum used to determine the structure, is still constant because there is no change going on. However, when pepsin takes action, TD-NMR, a special technique used for measuring mobile water population with macromolecular solutes, reveals that progressive unbundling of meat fibers helps pepsin activity to digest. TD-NMR data proves that bolus structure changes considerably during the first part of digestion and water molecules, consequently, leave the spaces inside the myofibrils and fiber bundles. This results in a low level of water that can be detected in duodenal stage. Since digestion is in progress, protein molecules become smaller and molecular weight gets lower, in other words, there is an increase in the spectra total area.