Fermentation of salted shrimp involves the interaction
of multiple
factors. However, studies of the effects of shrimp variety and fermentation
temperature on metabolites generated during fermentation are limited.
Therefore, we investigated the effects of the shrimp variety, fermentation
temperature, and fermentation period on the composition of fermented
salted shrimp. Four different varieties of salted shrimp, namely,
Detteugijeot
(SSA),
Red shrimp jeot
(SSB),
Chujeot
(SSC), and
Yukjeot
(SSD), were
prepared and stored at 5 and 10 °C for 5 months. The pH values
ranged from 6.71 to 6.99, with SSD showing the lowest pH at both temperatures.
Although total nitrogen content remained relatively constant, amino
nitrogen exhibited an upward trend after 2 months and was particularly
increased at 10 °C. This increase was attributed to variations
in microorganisms and enzymes in the salted shrimp. Except for proline,
citrulline, and ornithine, amino acid levels increased during fermentation
with the highest amounts detected in SSA. Additionally, the levels
of glutamic acid and branched-chain amino acids were found to be sensitive
to fermentation temperature. Amino acid levels were apparently affected
by species-specific metabolic pathways of the microorganisms present
in each salted shrimp. Compared to the other varieties, SSB had significantly
higher contents of adenosine triphosphate and hypoxanthine. A high
hypoxanthine content could contribute to increased bitterness and
an umami taste profile. Furthermore, the correlation between salted
shrimp and metabolites was unique in SSB, whereas partial clustering
was observed between the SSA and SSC.