Effects Of Ultra-high Pressure Treatments On The Qualities Of Silver Carp Surimi

Silver carp is one of the largest freshwater fish production in the country, due to its muscle among many thorns and smell of the soil is heavy, leading to lower consumer acceptability, thus resulting in a relatively low price of silver carp. Silver carp surimi processed into frozen surimi and surimi-based products can effectively increase their added value, in order to address more than the amount of silver carp problem but inexpensive. Surimi after high pressure treatment can improve the quality of their gels,and without heating can produce a smaller loss of flavor and nutrition of new surimi products.In this paper, the changes of flavor nucleotides and free amino acids of silver carp surimi in the rinsing process were studied, as well as the volatile compounds of surimi were analyzed by electronic nose and GC-MS. The results showed that the content of IMP was reduced significantly after the first and second rinsing, as the content of AMP after the third rinsing was less than the unwashed surimi. The amount of free amino acids was reduced significantly after the first, second and third rinsing, meanwhile the content of umami amino acids and sweet amino acids was reduced in the rinsing process.On the other hand, rinsing process also had an effect on the aroma of the silver carp surimi. The results of electronic nose showed that the aroma of surimi after the second rinsing was similar to dehydrated surimi, while other groups were distinguished effectively. Furthermore, the amount of volatile compounds found in unwashed surimi,the surimi after first rinsing, second rinsing, third rinsing and dehydration was30,27,21,15 and 18, respectively. They were detected by GC-MS, most of them were carbonyl compounds and alcohols, such as Hexanal, Heptanal, Nonanal, 1-Hexanol and1-Octen-3-ol.Meanwhile, the experiment of different pressures(100、200、300、400、500MPa)and different time(5、10、15、20、25min)on the silver carp surimi gel strength, whiteness,myofibrillar protein thermal denaturation temperature, volatile basic nitrogen content and ultrastructure. Gel strength increased significantly with increasing pressure, when the pressure reaches the gel strength 400 MPa maximum, and later significantly reduced dwell time in the gel strength did not change significantly after 10min; surimi whiteness as increasing the pressure increases, but with different values of whiteness dwell time had no significant effect; during storage increases significantly reduce volatile basic nitrogen content of surimi with pressure at high pressure treatment time was 10 min,minus the most significant small; high pressure treatment can significantly improve the thermal denaturation temperature surimi myofibrillar proteins, but to increase the value of a smaller temperature; high pressure treatment has a significant effect on the microstructure of silver carp surimi gel, and when the pressure to 400 MPa, dwell time is10 min, the maximum degree of uniformity dense gel microstructure.Starch gel properties and additives for silver carp surimi is also more significant.By high pressure treatment and adding four starch can be seen in the surimi, add potato starch and corn starch, the silver carp surimi gel strength value is larger; when adding wheat starch and potato starch, surimi whiteness high; it can be seen by scanning electron microscopy images, add wheat starch and potato starch in surimi, the microscopic structure of silver carp surimi is more compact and uniform.Secondly, the amount of starch added is optimized, by comparing the different amounts of surimi indicators can be found, the gel strength with the increase of the added amount of starch is increased, the addition amount of 20% starch gel strength of surimi although large, but breaking strength is low; with the increasing amount of added starch, white silver carp surimi was gradually decreasing trend; SEM images can be seen surimi microstructure 10% starch added amount of the most compact and uniform.Surimi index by adding 1% ovalbumin and 1% of the soy protein and high pressure treatment can be found, add ovalbumin better than adding soy protein significantly increased gel strength of silver carp surimi; contrast whiteness You can learn,ovalbumin and soy protein can make significantly improved whiteness, and added ovalbumin when compared to the higher value of whiteness; add two proteins couldsignificantly increase water retention surimi and add ovalbumin silver carp surimi allows higher water retention; by contrast SEM images can be found, add egg albumin and soy protein can make silver carp surimi gel network formation of a dense,homogeneous structure, and add soy protein when surimi more dense and uniform microstructure.Silver carp surimi 1% carrageenan and high pressure treatment can significantly increase silver carp surimi gel strength; adding carrageenan and ultra-high pressure treatment on the whiteness of surimi has significantly increased, but the increase in the value of whiteness smaller; EHV and silver carp surimi added carrageenan impact on water retention significant but smaller increase water retention values; by contrast SEM images can be found, UHP and add carrageenan can make chub fish Mi form a dense uniform gel network structure, and the two processes at the same time use the microstructure of the most compact and uniform silver carp surimi.Chub surimi after high pressure treatment and 0.5% transglutaminase(TGase) can make a significant increase in gel strength and water retention, but has little effect on whiteness, electronic scanning microscopy analysis indicates, TGase of silver carp surimi can join to form a dense uniform gel network structure.