Abstract: In this paper, vacuum packaged sauced sheep stomach was used to evaluate its sensory quality as affected by ultra high pressure (UHP) treatment. UHP treatments were carried out under varying conditions of pressure (100, 250 and 400 MPa) and holding time (5, 10, 15, 20 and 25 min) and at a constant temperature of 25 ℃. The physicochemical and functional properties and sarcoplasmic protein characteristics were studied by the biuret method, circular dichroism spectroscopy and scanning electron microscopy in order to investigate the effect of UHP on the microstructure and sarcoplasmic protein characteristics of sauced sheep stomach. The results showed that sensory quality significantly differentiated between UHP-treated and untreated samples. UHP treatment led to exposure of internal groups on the protein surface and alterations in the protein secondary structure. After the treatment, the contents of the stable secondary structures α-helix and β-sheet increased and decreased respectively, while the contents of irregular β-turn and random coil did not significantly change. In addition, UHP treatment caused an increase in carbonyl content, surface hydrophobicity and turbidity, and a decrease in total sulfhydryl content, free ammonia content and solubility. UHP treatment under 400 MPa and 25 ℃ for 20 min could cause moderate oxidative denaturation of sarcoplasmic protein, changes in the microstructure, and eventually improve the sensory quality of sauced sheep stomach.

Key words: ultrahigh pressure, sauced sheep stomach, sensory quality, microstructure, sarcoplasmic protein