• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.437-442
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• 2022

Squid jeotgal is a very popular traditional, salted, and fermented seafood in Korea. Due to the development of a distribution structure, a lot of imported squid jeotgal has recently entered Korea. In this study, we analyzed and compared the microbial contamination levels of domestic and imported squid jeotgal. The total viable bacterial count in domestic and imported jeotgal was 5.20 and 5.38 log CFU/g, respectively. The highest contamination level was 6.94 log CFU/g in one of the imported squid jeotgal samples. Coliforms were not detected in domestic jeotgal but were detected at 50% with 2.21 log CFU/g in imported jeotgal. Escherichia coli and Staphylococcus aureus were not detected (ND: <1 log CFU/g) in both domestic and imported jeotgal. All samples of jeotgal were negative for Bacillus cereus and Clostridium perfringens. The microbial contamination levels determined in the current study may be utilized as primary data to execute microbial risk assessments on domestic and (or) imported jeotgal.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.515-522
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• 2021

Jeotgal is a salty and fermented traditional Korean fish sauce. Unlike most other previous studies that investigated samples purchased from retail markets, this study focused on samples of jeotgal with traceable history to Yeonggwang, a timehonored fishing village in Korea. Three jeotgal samples, which were made from small yellow croakers, largehead hairtail, and miscellaneous fish, were selected based on information obtained from interviews with local craftsmen and literature reviews. Bacterial community profiles of the three jeotgal samples were investigated to identify indicator (and potentially core) bacteria for jeotgal ripening. The 16S rRNA gene-based metagenomic analysis revealed that the dominant phyla and classes, (Gammaproteobacteria, Betaproteobacteria, Bacilli, and Clostridia) of the three different jeotgal were identical, albeit with different composition ratios. Diversification was evident beginning at the order level. Interestingly, each dominant order was mainly comprised of single members even at the genus level. The dominant genera included Halomonas, Tetragenococcus, Halanaerobium, Pseudomonas, Massilia, and Lentibacillus. This observed genus-level heterogeneity suggests that there are diverse bacterial signatures in jeotgal and that these can be used as indicators for jeotgal ripening and/or as starters to increase its sensory quality and functionality.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.294-300
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• 2011

Proteolytic bacteria were isolated from Myeolchi-jeotgal and Saeu-jeotgal using high-salt-content media and their growths in the media containing 25% NaCl were monitored to draw the role of bacteria in the ripening of jeotgal. The most populous genus in Myeolchi-jeotgal detected on agar media with 15% NaCl was Bacillus and its relatives, while the most populous in Saeu-jeotgal was Staphylococcus. Among the isolates, Virgibacillus halodenitrificans from Myeolchi-jeotgal and Halobacillus trueperi from Saeu-jeotgal showed proteinase activities. The species from Myeolchi-jeotgal showed proteinase activity on the agar media with 8% NaCl were similar to those isolated from the media with 15% NaCl. The dominant of Myeolchi-jeotgal isolated at the 15% NaCl concentration may be involved in the proteolysis. The proteolytic species from Saeu-jeotgal on the agar media with 8% NaCl were the genera Bacillus, Salinicoccus, and Salimicrobium those were not the dominants at 15% NaCl condition. The dominant isolates from Saeu-jeotgal on agar media with 15% NaCl may not be involved in the proteolysis of Saeu-jeotgal. Vb. halodenitrificans and Staphylococcus equorum, the dominant species from Myeolchi-jeotgal and Saeu-jeotgal, showed growths at the nutrient broth containing 25% NaCl. They may play a significant role in the ripening of jeotgal and have a high possibility to be used as the starter.

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1112-1121
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• 2018

Jeotgal is a Korean traditional fermented seafood with a high concentration of salt. In this study, we isolated lactic acid bacteria (LAB) from galchi (Trichiurus lepturus, hairtail) and myeolchi (Engraulis japonicas, anchovy) jeotgal on MRS agar and MRS agar containing 5% NaCl (MRS agar+5% NaCl), and identified them by using 16S rRNA gene sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as culture-dependent methods. We also performed polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) as a culture-independent method to identify bacterial communities. Five samples of galchi-jeotgal and seven samples of myeolchi-jeotgal were collected from different regions in Korea. A total of 327 and 395 colonies were isolated from the galchi- and myeolchi-jeotgal samples, respectively. 16S rRNA gene sequencing and MALDI-TOF MS revealed that the genus Pediococcus was predominant on MRS agar, and Tetragenococcus halophilus on MRS agar+5% NaCl. PCR-DGGE revealed that T. halophilus, Tetragenococcus muriaticus, and Lactobacillus sakei were predominant in both types of jeotgal. T. halophilus was detected in all samples. Even though the same species were identified by both culture-dependent and -independent methods, many species identified by the culture-dependent methods were not in the bacterial list identified by the culture-independent methods. The distribution of bacteria in galchi-jeotgal was more diverse than in myeolchi-jeotgal. The diverse LAB in galchi- and myeolchi-jeotgals can be further studied as candidates for starter cultures to produce fermented foods.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1428-1433
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• 2013

Jeotgal fermentation is dependent upon a diverse microbial community, although a detailed understanding of its microbial composition is limited to a relatively small number of jeotgal. Pyrosequencing-based bacterial community analysis was performed in fermented squid, ojingeo jeotgal. Leuconostoc was identified as the predominant bacterial genus, with Bacillus and Staphylococcus also accounting for a large proportion of the bacterial community. Phylogenetic analysis with 16S rRNA genes of Leuconostoc type species indicated that L. citreum- and L. holzapfelii-like strains could be the major Leuconostoc strains in jeotgal. High concentrations of NaCl were thought to be an important factor determining the makeup of the bacterial community in the fermented squid; however, a genomic survey with osmotic stress-related genes suggests the existence of more complex factors selecting the dominant bacterial species in fermented squid.

• Korean Journal of Veterinary Research
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• v.54 no.3
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• pp.139-146
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• 2014

Jeotgal (salted seafood) has been one of major fermented foods in Korea for long time. Although there are many studies about Jeotgal in various aspects of food, its immunological importance on hosts has not been elucidated yet. In this study, we investigated if several bacteria isolated from Jeotgal may modulate the function of dendritic cells (DCs), powerful antigen-presenting cells equipped with special immunological capabilities. 4 Jeotgal bacteria were selected as representatives and used for experiments. To treat viable DCs, those bacteria were killed at $60^{\circ}C$ for 30 min. The viability of DCs treated with Jeotgal bacteria was verified and two isolates significantly induced high production of interleukin-12, a representative cell-mediated cytokine of DCs. Surface activation and maturation markers (MHC class II, CD40, CD86) of DCs were analyzed by flow cytometer. In addition, the treated DCs showed significantly high lymphocyte stimulatory capability compared to control DCs based on allogeneic mixed lymphocyte reactions. These observations suggest that Jeotgal isolates can function as immunostimulating bacteria in hosts, like Lactobacillus. Taken together, these experimental evidences may broaden the use of Jeotgal isolates in immunological fields in addition to as a fermented food.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.48-53
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• 2002

The HACCP (hazard analysis critical control point) concept becomes an important aspect of Good Manufacturing Practices (GMP) in safe food production. The HACCP plan was developed with food safety objective. The authors already carried out hazards analysis on Changran Jeotgal manufacturing process in a previous report. In this study we developed a HACCP plan on the manufacturing process of Changran Jeotgal. We could decide two CCPs those were salt concentration and eliminations of foreign materials before packaging. Foreign materials should be certainly checked out with laser detector just before packaging. Salt should be maintained more than $8\%$ to inhibit pathogenic bacteria in end product. On the Jeotgal process free water is removed after salting and Jeotgal is seasoned with several subsidiary materials such as com syrup. In result end products have $8\%$ salt with water activity 0.82. Most bacteria are inhibited but some can live in this condition. Materials on the working may be contaminate by pathogens, chemicals or physical hazards. It will be decreased by SSOP (standard sanitary operating program). The SSOP needed in Jeotgal plants is nearly same as other general food manufacturing plants but essential to fulfill HACCP program.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.327-332
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• 2003

We Isolated strains of Micrococcus sp., Pseudomonas sp., Leuconostoc sp. which have protease activity in the Changran-Jeotgal. These microbes were added in the Changran-Jeotgal for the starters during fermentation to short fermentation period to check PH, VBN, $NH_2-N,$ free amino acids, and sensory evaluation. Microbiological changes were also examined for microorganism-added Changran-Jeotgal and the control. Viable cell counts in the microorganism-added Changran-Jeotgal increased from $7.1\times10^5\;CFU/g\;to\;7.5\times10^8\;CFU/g$ on 15th day, The cell counts in the control increased from $4.1\times10^5\;CFU/g\;to\;8.1\times10^8\;CFU/g$ on 30th day. VBN also increased in both. Increasing rates of $NH_2-N$ and free amino acids in the microorganism-added Changran-Jeotgal were faster than those in the control. Sensory evaluation showed that the microorganism-added Changran-Jeotgal was most favorable on 20th day. These results showed that fermentation period was shortened about 10 days in comparison with the control.

• Journal of Applied Biological Chemistry
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• v.60 no.2
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• pp.133-136
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• 2017

Fermentation plays a vital role in the nutritional enrichment of food. Korea has a long tradition of adding fermented food to the daily diet and jeotgal is one of the common fermented and salted foods in Korean cuisine. In our study, we added soymilk as an additive to squid jeotgal to improve its functionality. We mixed different concentrations of soymilk (2, 5, and 10 mg/g) with squid jeotgal samples, fermented them for one week, and then tested their antioxidant and anticancer activities to compare with those of squid jeotgal samples without soymilk additive. To investigate the anticancer characteristics, glutathione-S-transferase (GST)-pi enzyme assay was used. To test the antioxidant activities, various assays were performed, including 2,2-diphenyl-1-picryl hydrazyl free radical scavenging activity, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium saltradical cation scavenging assay, and reducing power assay. Samples fermented with a small amount of soymilk showed excellent anticancer activity. The addition of only 2 mg/g of soymilk to squid jeotgal inhibited the activity of GST-pi by almost 50% when compared with the sample with no addition. Moreover, no undesirable bitterness or astringency was noticed. Our results could help to improve the current food status of squid jeotgal and it could be used to reduce the risk of chronic disease along with its basic nutritional function.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.195-203
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• 2014

We investigated the effect low salt (2 or 4% salt) concentrations jeotgal made from Todarodes pacificus on the learning and memory impairments in scopolamine-induced (2 mg/kg, i.p.) dementia rats. Rats treated with oral BF-7 (200 mg/kg, p.o.) as a positive control and Todarodes pacificus jeotgal had significantly reduced scopolamine-induced memory deficits in the passive avoidance test. The Morris water maze test or treatment with 2% salt jeotgal made from Todarodes pacificus significantly ameliorated the scopolamine-induced memory deficits in the formation of long- and short-term memory. The acetylcholine content and acetylcholinesterase acitivity paralleled the results of the behavior experiment. There were no significant differences in the brain acetylcholine contents of the experimental groups, while the brain acetylcholine content of the group treated with 2% salt Todarodes pacificus jeotgal was higher than that of the control group. The inhibitory effect of 2% salt jeotgal made from Todarodes pacificus on the acetylcholinesterase activity in the brain was lower than that of the control group. These trends were similar to those of the gamma-aminobutyric acid content. We suggest that Todarodes pacificus jeotgal enhances learning memory and cognitive function by regulating cholinergic enzymes.