Dynamic Changes in the Bacterial Community and Metabolic Profile during Fermentation of Low-Salt Shrimp Paste (Terasi).

Henny Helmi,Walter A Laviña,Eiichiro Fukusaki,Pingkan Aditiawati,Sastia Prama Putri,Dea Indriani Astuti,Arisa Sato

doi:10.3390/metabo12020118

Abstract

Low-salt shrimp paste, or terasi, is an Indonesian fermented food made from planktonic shrimp mixed with a low concentration of salt. Since high daily intake of sodium is deemed unhealthy, reduction of salt content in shrimp paste production is desired. Until now, there is no reported investigation on the bacterial population and metabolite composition of terasi during fermentation. In this study, the bacterial community of terasi was assessed using high-throughput sequencing of the 16S rRNA V3–V4 region. From this analysis, Tetragenococcus, Aloicoccus, Alkalibacillus, Atopostipes, and Alkalibacterium were found to be the dominant bacterial genus in low-salt shrimp paste. GC/MS-based metabolite profiling was also conducted to monitor the metabolite changes during shrimp paste fermentation. Results showed that acetylated amino acids increased, while glutamine levels decreased, during the fermentation of low-salt shrimp paste. At the start of shrimp paste fermentation, Tetragenococcus predominated with histamine and cadaverine accumulation. At the end of fermentation, there was an increase in 4-hydroxyphenyl acetic acid and indole-3-acetic acid levels, as well as the predominance of Atopostipes. Moreover, we found that aspartic acid increased during fermentation. Based on our findings, we recommend that fermentation of low-salt shrimp paste be done for 7 to 21 days, in order to produce shrimp paste that has high nutritional content and reduced health risk.

Highlights

Fermented shrimp products, such as sauces and pastes, and lacto-fermented products are widely consumed in China and Southeast Asian countries [1,2,3]
The findings of this study will be helpful in the fermented food industry, in order to assess the optimal length of fermentation time for the production of good quality shrimp paste or terasi
We found that high levels of glutamic and essential amino acids are present at the T1 and T2 stages (7 and 14 days), and there are increased Maillard reaction products at the T3 stage (21 days); it is recommended that the fermentation should be stopped on the 7th day and should not go over 21 days

Summary

Introduction

Fermented shrimp products, such as sauces and pastes, and lacto-fermented products are widely consumed in China and Southeast Asian countries [1,2,3]. These fermented products, known by their native names in different countries, are usually used as side dishes, condiments, or main dishes [1,2,3,4]. One of the famous fermented shrimp products in China and Southeast Asia is shrimp paste It has high nutritional value because it contains amino acids, proteins, carotenoids, chitins, unsaturated fatty acids, and minerals, such as calcium, sodium, and phosphorus [4,5,6]. Aside from its high nutritional value, shrimp paste has been reported to exhibit antioxidant properties [4,5,7,8]

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