The changes in the electrical conductivity (EC) and taste nucleotides of Litopenaeus vannamei shrimp with the treatment of ohmic heating (OH) were investigated in order to investigate the effect of OH on the taste of Litopenaeus vannamei. The EC (50 Hz~20 kHz) and the contents of nucleotides in the shrimp under different temperatures (25, 40, 55, 65, 75, 85, and 95 ℃) and metal ion additives (1, 5, and 10 mmol/L Zn2+, Cu2+, Al3+, Fe3+) were measured. The results show that the EC of minced shrimp has a logarithmic relationship with frequency and a linear relationship with temperature (lower than 65 ℃) (P<0.05). The EC of shrimp with added metal ions was higher than that of pure shrimp and 10 mmol/L Fe3+ was the best conductor for shrimp. In the treatment of OH, the guanosine monophosphate(GMP) content was always at a high level (more than 60 mg/100 g), while the Hypoxanthine(Hx) and Inosine(HxR) contents were always at a low level (less than 7 mg/100 g). Adenosine(AdR) was accumulated at high temperatures. The best temperature of heating for pure shrimp by OH was between 55~65 ℃, which was conducive to the production of umami taste. The shrimp treated with metal ions produced a small amount of Hx and a large amount of inosine monophosphate(IMP) at different temperatures. There was no significant correlation between IMP production and metal ion concentration (P>0.05). The IMP content in shrimp was the highest (201.39±3.83 mg/100 g) when 10 mmol/L Fe3+ was added and ohmic heated to 85 ℃. This study provided the optimized treatment condition for Litopenaeus vannamei using OH.
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