• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.237-245
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• 2016

In this study, the physicochemical and sensory characteristics of low-salt Myungran jeotkal (Alaskan pollock roe) were evaluated after fermentation at $4^{\circ}C$ and $20^{\circ}C$ with or without the addition of deep sea water, salt from deep sea water, and vegetable-origin lactic acid bacteria (Lactobacillus fermentum JS, LBF). When fermented at $20^{\circ}C$, the addition of LBF to Myungran jeotkal resulted in a slow increase in lactic acid content, followed by an abrupt increase after five days of fermentation. However, when fermented at $4^{\circ}C$, the lactic acid content did not change significantly. Further, when Myungran jeotkal fermented at $4^{\circ}C$, the pH decreased as lactic acid production increased. The salinity of Myungran jeotkal fermented at $4^{\circ}C$ and $20^{\circ}C$ was 7% and was not affected by fermentation period. When fermented at $20^{\circ}C$, volatile basic nitrogen and amino nitrogen contents increased with increasing duration of fermentation. Further, volatile acid content decreased, however, the content of amino nitrogen increased after 11 days of fermentation with LBF and no salt effects were observed. When fermented at $20^{\circ}C$ for 13 days, preference (sensory evaluation) was the highest in all experimental groups after 9 days of fermentation, and then decreased as the fermentation period increased. The free amino acid content was highest (1,648.8 mg/100 g) in Myungran jeotkal when sun-dried salt and LBF were added, 2.3 times higher than in the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.261-267
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• 1995

Low-salted and fermented squid product, squid jeotkal was prepared with the addition of 10% salt and fermented for 50 day at 1$0^{\circ}C$. During fementation of squid, sensory evaluation and changes of volatile components were examined. Volatile flavor components in raw squid and low-salted squid jeotkal were extracted using a rotary evaporating system. The volatile concentrates were identified by GC and GC-MS. Major volatile components of raw squid were methional and 2-methyl-2-propanol. However, alcohols such as propanol, isoamyl alcohol, methionol and phenylethyl alcohol increased during the period of fermentation. The model reaction using microorganism was carried out, in order to confirm formation mechanism ofvolatile flavor compounds of the squid during fermentation. The main volatile components of Pseudomonas sp. D2 model system were isoamyl alcohol and acetoin. Those of Staphylococcus xylosus model system were isoamyl alcohol and phenylacetaldehyde.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.36-43
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• 1999

A study on the hydrolysis of anchovy using proteolytic bacteria isolated from anchovy jeotkal (a salt-fermented fish) was carried out to develop a rapid process of liquefied anchovy jeotkal. Five kinds of proteolytic bacteria, such as Staphylococcus sp.-l, Photobacterium sp., Volcaniella sp., Staphylococcus sp.-2 and Bacillus sp., were isolated from the anchovy jeotka1 that fermented with $20\%$ NaCl at room temperature for 2 months. Those grew well at $40^{\circ}C$, pH 7.0 on TPY broth with $2.0\%$ NaCl. The optimal hydrolysis temperature, pH, time and proteolytic bacteria densities for hydrolysis of minced anchovy were$40^{\circ}C$, 7.0, 6 hours and $1.8\times10^8$ cells/g raw anchovy, respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1050-1056
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• 1999

The effect of ${\gamma}-irradiation$ was investigated on salted and fermented squid, squid jeotkal. Squid jeotkal was prepared with salt concentrations of 5%, 10% and 20% and was fermented at $15^{\circ}C$ and $25^{\circ}C$ after ${\gamma}-irradiation$ with doses of 0, 2.5, 5 and 10 kGy, respectively. Proximate composition, salinity, water activity (Aw), pH, total bacteria and sensory evaluation were examined during fermentation periods. Results showed that ${\gamma}-irradiation$ had no effect on proximate composition, salinity and Aw compared with non-irradiated squid jeotkal. However, pH and total bacteria, as well as sensory evaluation, were changed variously with processing conditions such as NaCl concentration, irradiation dose and fermentation temperature. The results of total bacteria and sensory evaluation showed that squid jeotkal with NaCl concentration of 10% and an irradiation dose of 10 kGy maintained high quality for 30 days at $15^{\circ}C$. Therefore, it was considered that ${\gamma}-irradiation$ was effective in processing low-salted squid jeotkal and extending its shelf-life without adding any food additives.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.89-90
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• 2003

Fermented fish (jeotkal) has been used as a method of preserving perishable fish and marine products. Recently, however, high salted jeotkal (20% and more) has avoided from consumer by reasons of organoleptic quality (high salinity), health value (degenerative chronic disease), and hygienic safety. Among these jeotkals, meanwhile, sikhae (lactic acid fermented fishes) has been traditionally favored in the eastern coastal area of Korea, which contain below 10% of salt content with acidic range (pH4∼5). (omitted)

• Microbiology and Biotechnology Letters
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• v.15 no.5
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• pp.301-305
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• 1987

Moderate halophilic bacteria isolated from several kinds of salted and fermented sea foods (jeotkal) collected from commercial market were identified and investigated on their selt requirements. It was confirmed that the isolates were dominantly moderate halophiles according to their NaCl requirement to grow. And their salt requirements in their growth have been examined for Na, K, Ni and mg ions. Among them, the most dominant and distinctive three strains in protease pro-duction have been examined and two of them identified to be halophilic Flavobacterium sp., and the other one to be halophilic Pseudomonas sp..1'heir optimum growth was observed at 3$0^{\circ}C$ and at 10 percent of NaCl.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.862-874
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• 2014

Salt-fermented fish and fish sauce are very important materials to make Kimchi. They provide good taste and plenty of nutrition to Kimchi during fermentation. However, it is difficult to purchase Korean salt-fermented fish or fish sauce out of Korea. Therefore, to generalize Kimchi for other countries, this research carefully compared the quality differences between Kimchi made with South East Asian fish sauce, which is fairly similar to traditional Korean salt-fermented anchovy extract (Aekjeot) in terms of taste and ingredients, and that made with traditional Korean salt-fermented anchovy extract. To determine quality differences among traditional Korean Kimchies made with different sauces, Korean-made salt-fermented shrimp, salt-fermented shrimp extract, salt-fermented anchovy and salt-fermented anchovy extract were used. Of the four Kimchis, the one made with salt-fermented anchovy extract was chosen as a control sample and compared with those made with three different South-East Asian fish sauces. In the sensory evaluation for acceptance of fish sauces, characteristics of taste, texture and overall acceptance showed significant differences. In the sensory evaluation for differences, characteristics of fish odor and crunchiness showed visible differences. For umami taste, all fish sauces received higher points than Korean salt-fermented anchovy extract (control sample), although the difference was not significant. Sensory evaluation and research results show that Kimchi can become a highly likable food overseas and Kimchi can substitute easily bought South-East Asian fish sauces for Korean salt-fermented fish sauces (Jeotkal).

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.636-641
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• 1995

Proteolytic activities were compared using three species involving in squid jeotkal fermentation and showing positive reaction upon casein test : Pseudomonas D2, Flavovacterium odoratum and Acinetobacter calcoaceticus. Pseudomonas D2 produced highest activity of protease at 72h when incubated in our own modified medium(polypeptone, 0.5% ; tryptone, 0.5% ; NaCl, 3% ; pH, 7.5). Thus, this specie was selected for the further study. The growth pattern was coincided with the production of protease. Thus purification of protease was proceeded by ethanol precipitation, sephadex G-100 gel filtration, and DEAE sepharose ion exchange chromatography. The purified protease showed highest activity at pH 7.0 and 5$0^{\circ}C$. The enzyme was very stable over the wide ragnes of the temperature ; even with one hour heat treatment at 7$0^{\circ}C$, the enzyme showed substantial amount of the activity toward casein. In addition, the enzyme was stable over the wide range of pH. Molecular weight of the protease was determined to be 17.4 kD by SDS-PAGE.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.940-946
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• 1996

One of the biggest Problems in making jeotkal is the reduction of its shelf-life when lowering the salt content from 20-30% to below 10%. Therefore, in order to extend the shelf-life of the low-salted jeotkal, prior to setting the minimum allowance value of sulfiting agents as food additives for fermented fish products, the preservative effects of sulfite salts on the low-salted myungranjeot (soused roe of Alaska pollack) were studied through various chemical and microbial analyses. The pHs of the low-salted Myungranjeot treated with bisulfite and metasulfite salts rapidly decreased in the biginning of fermentation, while the lactic acid contents increased constantly. Sodium bisulfite and metasulfite enhanced the production of $NH_2-N$ after 10 day-fermentation, whereas they inhibited the production of VBN, TMA and TBA, and the growth of microorganisms including fungi during fermentation. The estimated shelf-lives of low-salted myungranjeot treated with control, sodium sulfate, sodium bisulfite, and sodium metasulfite on the basis of VBN 50 mg% were about 16, 14, 20 and 24 days, respectively.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.