Effect of High Pressure and/or Temperature over Gelation of Isolated Hake Myofibrils
© 2014, Springer Science+Business Media New York. High hydrostatic pressure (HHP) processing was used to determine its ability to induce protein gelation. Isolated hake myofibrils were processed by HHP at 0, 150, 250, and 500 MPa (10 ºC/10 min) and/or by heating (90 ºC/20 min). The results were analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), determination of sulfhydryl group contents, and dynamic rheometry measurements. FTIR data indicated that secondary protein structures exhibited a reduction in α-helix together with an increase in β-sheet as a result of protein denaturation caused by HHP. DSC showed that HHP induced a reduction in myosin denaturation temperature (Tpeak) indicating protein unfolding. Protein gelation after HHP is based on physical (non-covalent) interactions which make more sulfhydryl groups available, while after heating, it is based on the formation of covalent (disulfide) bonds as a consequence of protein denaturation reducing the sulfhydryl groups. The combination of HHP and heating, particularly the latter, improved network stabilization. These results were reflected in the rheological changes, in which heated gels showed more elastic, cohesive, and time-stable networks than pressurized (non-heated) gels. The HHP effect provided softer, more flexible networks. The gel at 500 MPa was the most elastic and time-stable and exhibited the highest level of connectivity.
| Main Authors: | , , , , |
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| Format: | artículo biblioteca |
| Published: |
Springer
2014
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| Subjects: | Viscoelastic properties, Myofibril, Physicochemical properties, High pressure, |
| Online Access: | http://hdl.handle.net/10261/111435 |
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