Abstract
High pressures of 1, 000 to 5, 000 atm were applied to beef rounds to study the effects of pressure on the proteolytic activities involved. Acid protease was scarcely inactivated, and neutral protease was slightly inactivated at 4, 000 atm or higher. Aminopeptidase and carboxypeptidase were completely inactivated at 5, 000 and 4, 000 atm, respectively. The autolytic activity of the extract from pressure-treated beef at pH 3.0 to 6.0 increased with increasing applied pressure, while that at pH 6.5 to 8.0 showed two maxima at 3, 000 and 5, 000 atm. The increase in free amino acid content was amplified by pressurization at 1, 000 to 3, 000 atm, and the tryptic digestibility of the extract from the pressurized beef was increased at 4, 000 atm or higher. These results suggest that high-pressure treatment modulates the proteolytic activities of meat to improve its quality.
