• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.665-671
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• 1996

Changes in the nutritional components of Toha-jeot, salt-fermented Toha shrimp(Caridina denticulata denticulata $D_{E} H_{AAN}$), which was salted with 20%(w/w) sodium chloride and fermented during 60 days at $4\pm1^{\circ}C$ were investigated. The free amino acid contents in Toha-jeot, of which glutamic acid, leucine, Iysine, arginine, glycine and alanine occupy the majority, in order of abundance, increased gradually up to 50 days of fermentation. Most of the nucleotides were decomposed to hypoxanthine; thus ATP and ADP were not detected. Fermentation decreased inosine, IMP and unsaturated fatty acid contents and increased saturated fatty acid contents of Toha-jeot. Palmitic acid was the most abundant fatty acid, followed by palmitoleic acid, linoleic acid, EPA and stearic acid. Among the mineral constituents of Toha-jeot, Na and Ca were dominantly occupying. The Hunter "L" and "b" values of Toha-jeot increased during fermentation while "a" value remained unchanged.

• Korean Journal of Rural Living Science
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• v.10 no.2
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• pp.60-70
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• 1999

Changes in the nutritional components of Toha-jeot, salt-fermented Toha shrimp (Caridina denticulata denticulata $D_EH_{AAN}$), which was salted with a low-salt group of 15% sodium chloride (L), a high-salt group of 23% sodium chloride (H), a 50% conventional soybean sauce group (S) during long fermentation were investigated. These three groups were refrigerated at ${4\pm}1^{\circ}C$ and then taken out for analysis at three month intervals during 9 month. Even in the process of a long fermentation, the moisture containment of Toha-jeot in group L and S is 76.0~73.6% and in group H it is 70.0%, which are similar in all three groups. In case of the salinity, there was no change in groups L, H but it was lowered in group S during the fermentation. In all groups there was no change of pH. The free amino acid contents in Toha-jeot, of which ornitine, glutamic acid, leucine, alanine, lysine and valine occupy the majority, in order of abundance, increased gradually up to six months of fermentation and decreased by nine months. But free amino acid contents of S group increased continuously during the fermentation process. Hypoxanthine was altered almost among other nucleotides. ATP was not detected, IMP and inosine had disappeared after the six months for mentation. ADP was not detected after the nine months fermentation. Monoene, polyene and n-3 fatty acids were increased and saturated fatty acids were decreased in L and H groups. However, no changes of fatty acid contents in S group during fermentation were showed. The fatty acid contents of three groups, of which $C_{18:1},\;C_{16:0},\;C_{16:1}$ and $C_{20:5}$ occupy the majority, Mineral content of Toha-jeot is mainly consisted of Na, Ca, K and Mg. In the Hunter values, the redness of L group was superior to that of other groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.325-330
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• 1996

전남지방의 전통 수산발효식품인 토하젓의 인지도 향상 및 국가경쟁력을 갖춘 지역특산품으로 발전시키기 위한 일련의 연구로써, 식품학적 기초자료를 얻기위하여 숙성기간이 다른 시판 토하젓을 구입하여 정미성분을 분석.검토하였다. 저온(5$\pm$2$^{\circ}C$)에서 90일간숙성시킨 토하젓의 전체 유리아미노산 함량은 건물당 1873.0mg/100g)보다 2배이상 많았다. 한편 숙성된 토하젓의 주요 유리아미노산(719.4mg/100g) 보다 2배 이상 많았다. 한편 숙성된 토하젓의 주요 유리아미노산은 glutamic acid, alanine, leucine, valine 및 phenylalanine으로 전체 유리아미노산에 대해 58.6%를 차지하였다. 핵산 관련물질은 담금 직후 및 숙성된 토하젓 모두 hypoxanthine의 함량이 월등히 많았으며, 그 다음으로 AMP 및 IMP순이였다. 그리고 숙성된 토하젓은 담금 직후의 토하젓과 비교해서 AMP 및 IMP는 적었으나, hypoxanthine의 함량은 많았다. 불휘발성 유기산을 GC분석한 결과, 담금 직후 및 숙성된 제품 모두에 lactic acid가 가장 많아 각각 건물당 389.3mg/100g 및 752.3mg/100g이였고, succinic acid는 미량 함유되어 있었다. 90일간 숙성된 TMAO, betaine 및 total creatinine 함량은 건물량 기준으로 각각 63.6mg/100g, 179.1mg/100g 및 123.7mg/100g이었다. Omission test를 이용하여 각정미성분을 관능검사한 결과, 유리아미노산 및 불휘발성 유기산이 토하젓의 맛에 중요한 역할을 하는 것으로 밝혀졌으며, 핵산 관련물질은 그다지 맛에 대한 기여도가 높지 않았다. 따라서 시판 토하젓의 맛에는 유리 아미노산 및 불휘발성 유기산이 중요한 역할을 하며, 핵산 관련물질이나 TMAO, betaine 및 total creatinine은 보조적인 역할을 할 것으로 생각된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.791-795
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• 1996

Toha-jeot(salt-fermented Toha shrimp) is a traditional fermented food in Korea. Toha-jeot is fermented for 90 days at $4\pm1^{\circ}C$ with 20%(w/w) salt per live Toha shrimp. We expect that the high polymer chitin of Toha shell will be hydrolyzed by chitinase during the fermentation of Toha-jeot and that the low molecular weight of chitin oligosaccharides will be produced. We experimented 7 samples which were taken at the interval of 15 days during the total 90 days of fermentation. We also measured molecular weight of Toha-chitin, viscosity and molecular weight distribution of chitin during fermentation of Toha-jeot, The decrease of viscosity and average molecular weight of chitin were observed as fermentation proceeds. Chitin oligosaccharide with $10^3molecular$ weight was low until 60 days fer-mentation. However, chitin oligosaccharide with $10^3molecular$ weight was high after 75 days fer-mentation. And chitin oligosaccharide with $10^2molecular$ weight were observed after fermenting Toha for 75 days and 90 days, but chitin oligosaccharide with 10'molecular weight did not appear up to 60 days of fermentation.ation.

• Korean Journal of Human Ecology
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• v.3 no.2
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• pp.77-89
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• 2000

In this study, to activate the industrialization and to improve the quality of Toha-jeot by shortening the fermentation period, we investigated the changes in the nutritional components of Toha-jeot. salt-fermented Toha shrimp( Caridina denticulata denticulata $D_{E}$ $H_{AAN}$) which was salted with a low-salt group and high-salt group during fermentation. In this experiment. there are four groups of Toha-jeot which were manufactured with 15% ratio of common salt: the first group containing 2% wheat bran (w2%-L). the second high-salt group containing 2% wheat bran( w2%-H) , the third low-salt group containing 4% wheat bran (w4%-L) and the last high-salt group containing 4% wheat bran(w4%-H). These four groups were refrigerated at 4${\pm}$1$^{\circ}C$ and then taken out for analysis at three month intervals during 9 month. Among the free amino acid contents in Toha-jeot, 22 kinds were detected. 6 month after the fermentation when the quantity of the amino acid contents in Toha-jeot is highest, ornitine, glutamic acid, leucine. alanine. lysine and valine occupy the majority, in the order of abundance. In cases of nucleotides. 6 month after the fermentation. from the groups w2%-L, w2%-H and w4%-L, inosine and IMP were not detected. and hypoxanthine, AMP, ADP were detected but 9 month after the fermentation ADP was not detected. The main constituents of fatty acid were as follows : (a) from w2%-L, w2%-H, 6 month after the fermentation. $C16:0$, $C12:0$, $C18:1$, $C18:3$, and $C16:1$. (b) from w4%-L. 6 month after the fermentation, $C18:3$, $C16:0$, $C12:0$ and $C18:1$. (c) from W4%-H, $C16:0$, $C12:0$, $C18:3$ and $C18:1$. In case of mineral contents. Na, Ca. K. Mg, Fe. Zn, Mn and Cu were detected according to the magnitude of the quantity. From the group w4%-H, high quantity of Na was detected during the total fermentation period. In case of color value, from the groups w2%. the values of L. a. b were highest after 6 month fermentation and were decreased after 9 month fermentation, while from groups w4%, the values of L, a, b were gradually decreased after 3 month fermentation.ion.

• Food Science and Preservation
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• v.8 no.4
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• pp.419-426
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• 2001

This study was carried out to develope a convenient instant spiced Toha-jeot. Toha-jeot was manufactured by five samples; 8%, 10%, 13% 23% sodium chloride and a conventional type soy sauce. The Toha-jeot was refrigerated at 4$\pm$1$\^{C}$ for 3 months and then boiled glutinous rice, red pepper powder, chopped garlic and ginger were added, and the spiced Toha-jeot was fermented at 4$\pm$1$\^{C}$ for 2 months, was freeze-dried at a condition of 40$\^{C}$, vacuum 100∼200 millitor millitorr and then packed in vacuum. It is called freeze-dried instant spiced Toha-jeot (FIST). Changes in the components and quality of refrigerated spiced Toha-jeot (RST) and FIST were investigated for 30day. The moisture content of RST was 53.79∼58.91%. Among the mineral constituents of RST, Na and Ca were dominantly occupying. Water activity of FIST was 0.28-0.39 while that of RST was 0.87-0.92. TBA value of FIST was lower than that of RST. Acidity, VBN (volatile basic nitrogen) and TBA(thiobarbituric acid) of the FIST and RST increased slightly, whereas pH decreased. The major components of fatty acids in FIST and RST were analysed into a feater amount of linoleic acid (Cl8:2), palmitic acid (Cl6:1), oleic acid (Cl8:1), linolenic acid (Cl8:3), EPA (C2O:5) and stearic acid(Cl8:0). In sensory evaluation, the RST had higher scores in color and taste and the FIST in chewiness and flavor. The qualitative characteristics and sensory evaluation of FIST and RST were similar.