The improvement of gel and physicochemical properties of porcine myosin under low salt concentrations by pulsed ultrasound treatment and its mechanism

Mechanism of ultrasound and tea polyphenol assisted ultrasound modification of egg white protein gel

“…With the increase of ultrasonic power, the α-helices of TUEP showed an increasing trend, which may be because the α-helices were maintained by the hydrogen bonds (formed by the carbonyl group and amino group of polypeptide chain) [42] , and the increased polarity of protein may affect the hydrogen bond of α-helices, thus increasing the content of α-helices. Interestingly, the results of the α-helices in this study were contrary to those of porcine myosin gel under ultrasonic treatment [32] , suggested that the effects of ultrasonic treatment may be different for different proteins.…”

“…Surface hydrophobicity gradually increased with the increase of ultrasonic power, which indicated that the hydrophobic amino acid residues of protein were exposed to water environment by ultrasonic treatment. It may be because ultrasonic cavitation may generate strong shear force in the local protein sample, which would unfold of TUEP and UEP structure and expose the hydrophobic amino acid residues on protein surface [32] . The combination of polyphenols with protein (hydrophilic hydroxyl groups of polyphenols bind to lipophilic groups of protein) may promote protein aggregation, leading to the decrease of protein surface hydrophobicity.…”

“…When the protein aggregation rate was greater than the expansion rate, the protein would over-aggregate (such as the gel structure of the sample without ultrasound), and resulting in uneven distribution of protein aggregates and large protein particles [33] . The protein structure (tertiary structure and secondary structure) could be expanded by appropriate ultrasonic treatment, thus reducing the relative rate of protein aggregation [32] . Therefore, ultrasonic treatment improved the gel structure of TUEP and UEP.…”

Improvement of gelation properties of silver carp surimi through ultrasound-assisted water bath heating

“…However, ultrasound, combined with high temperatures, probably reduced the activity of endogenous proteases, with this having a negative effect on the gel properties [15] . Therefore, the hardness of the U + U group was slightly lower than that of U + W. In addition, the myofibrillar proteins could have been overextended after prolonged ultrasonic treatment, and this could have seriously impaired the conformation of the proteins, resulting in poor textural properties [31] .…”

“…Meanwhile, we observed that the WHC of the U + U group was lower than that of the U + W group. This could have been because ultrasound treatment at high power and for long periods of time caused protein oxidation and degradation [33] , thereby disrupting its orderly aggregation and forming a non-uniform three-dimensional network structure of the surimi gels [31] . In turn, such a non-uniform structure could have weakened the ability to hold onto water molecules, resulting in a decline in water content.…”