• Journal of Microbiology and Biotechnology
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• v.34 no.3
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• pp.654-662
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• 2024

To investigate the effect of the predominant fungal species from Korean traditional meju and doenjang on soybean fermentation, the enzymatic activity and amino acid production of twenty-two fungal strains were assessed through solid- and liquid-state soybean fermentation. Enzymatic activity analyses of solid-state fermented soybeans revealed different enzyme activities involving protease, leucine aminopeptidase (LAP), carboxypeptidase (CaP), glutaminase, γ-glutamyl transferase (GGT), and amylase, depending on the fungal species. These enzymatic activities significantly affected the amino acid profile throughout liquid-state fermentation. Strains belonging to Mucoromycota, including Lichtheimia, Mucor, Rhizomucor, and Rhizopus, produced smaller amounts of total amino acids and umami-producing amino acids, such as glutamic acid and aspartic acid, than strains belonging to Aspergillus subgenus circumdati. The genera Penicillium and Scopulariopsis produced large amounts of total amino acids and glutamic acid, suggesting that these genera play an essential role in producing umami and kokumi tastes in fermented soybean products. Strains belonging to Aspergillus subgenus circumdati, including A. oryzae, showed the highest amino acid content, including glutamic acid, suggesting the potential benefits of A. oryzae as a starter for soybean fermentation. This study showed the potential of traditional meju strains as starters for soybean fermentation. However, further analysis of processes such as the production of G-peptide for kokumi taste and volatile compounds for flavor and safety is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.767-774
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• 2015

In recent decades, health concerns related to sodium intake have caused an increased demand for salt or sodium-reduced foods. Umami substance can enhance taste sensitivity to NaCl and may offer a unique approach to replace and reduce the sodium content in foods. In this study, hot water extraction conditions of Wando sea tangle with high umami taste were investigated. Wando sea tangle harvested in June was selected for hot water extraction based on its free amino acids composition. The quality properties of sea tangle extract were investigated at various extraction temperatures ($60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$) and times (1 h, 2 h, and 3 h). Sea tangle extracts at the extraction temperature of $100^{\circ}C$ contained the highest soluble solids (35.47%~36.93%), and crude protein (3.75%~4.00%). Viscosities of sea tangle extracts decreased with increasing extraction temperature. Umami amino acids (glutamic acid and aspartic acid) and sensory characteristics were best at extraction conditions of $100^{\circ}C$ for 2 h. Saltiness enhancement of sea tangle extract powder was determined. Saltiness intensities of NaCl solution after adding 1% sea tangle extract powder were enhanced (1.84~4.25-fold). At the same saltiness intensity, sodium contents of NaCl solution with 1% sea tangle extract powder were 12.24~24.33% lower than that of NaCl solution. These results suggest that it is possible to reduce sodium in foods with sea tangle extract as a natural salt enhancer without lowering overall taste intensity.

• Journal of Oral Medicine and Pain
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• v.26 no.2
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• pp.127-131
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• 2001

The authors performed the taste threshold tests in two patients complaining taste problem who visited the Department of Oral Diagnosis, Seoul National University Dental Hospital. The taste thresholds were determined using a concentration series of five tastants, sucrose ( sweet ), NaCl ( salty ), citric acid ( sour ), quinine hydrochloride ( bitter ) and monosodium glutamate ( umami ). The taste solutions were diluted by half quarter logarithmic steps. The two patients showed higher taste thresholds level than normal but the taste threshold results did not coincide with the patients appeal. Further researches are needed for developing simple and precise diagnostic methods which can be applied to the patients with taste disorder.

• Korean journal of food and cookery science
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• v.19 no.2
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• pp.188-194
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• 2003

This study was conducted to investigate the effect of beef bone extracts on the organoleptic quality and fermentation of Baeck Kimchi. For this study, the organoleptic characteristics of Baeck Kimchi, with addition beef bone extracts were tested, and the changes in the fermentation factors, such as pH, acidity, reducing sugar and total microbial count, were observed during fermentation at 10$^{\circ}C$ and 20$^{\circ}C$. Greater amounts of lipids and soluble nitrogen were extracted to increasing the boiling time for the preparation of the beef bone extracts. However, 1% of the mixed beef bone extracts, prepared by boiling for 5, 7 and 9 hours, was the most acceptable for the Baeck Kimchi fermentation, as assessed from the results of sensory consumer tests. The beef bone extracts enhanced the umami taste of the unfermented Baeck Kimchi. The carbonated taste, sourness and fresh flavor of the fermented Baeck Kimchi were also enhanced. The fermentation rate was increased by the addition of beef bone extracts to Baeck Kimchi.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.303-308
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• 2011

To develop food and organoleptic quality of gochujang 0, 3, 4, and 5% of sweet persimmon powder were added to Korean traditional red pepper paste during fermentation and microbiological and organoleptic characteristics were investigated. The total bacteria count of the gochujang tended to increase slowly until a level of $10^8$ CFU/g with increasing fermentation time. There was no significant difference (p <0.05) between the control and the treatment during fermentation. The number of yeast and mold was $10^4-10^5$ CFU/g during fermentation. Sensory evaluation after 30, 60, and 90 days of fermentation showed that addition of sweet persimmon powder to the gochujang did not affect its color, but the level of sweetness and umami, increased as additional level of sweet persimmon powder increased. In the overall acceptabilty, there was no significant difference (p <0.05) until 30 days of fermentation and the gochujang added with 4% sweet persimmon powder showed the highest organoleptic value. And it showed high score in sweetness, umami and overall acceptability at the end of fermentation. The results indicated that 4% additional level of sweet persimmon powder was the best making gochujang.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.370-378
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• 2006

This study was carried out to investigate the effects of various subsidiary ingredients added to Kimchi on the acceptance and sensory characteristics. In appearance acceptance, Kimchi without red pepper powder rated the worst, while samples without salt-fermented anchovy extracts, garlic, ginger, radish, green onion and onion showed no significant difference(p<0.05) compared with the control, and were all rated highly in acceptance. In flavor, taste and overall acceptance, the sample without garlic rated the worst, indicating that garlic has the greatest effect on the acceptance of Kimchi. Red pepper powder had an effect only on the pungency of Kimchi's flavor characteristics. Salt-fermented anchovy extracts enhanced umami taste, sweetness and saltiness of Kimchi. Garlic also enhanced the general flavor such as sourness, umami taste, sweetness, carbonated flavor and fresh flavor, but inhibited the moldy flavor. Ginger had effects on pungency, fresh flavor of Kimchi, while radish, green onion and onion only had an effect on the fresh flavor of Kimchi. Garlic had significant effects on the moldy flavor and bitterness of Kimchi's sensory characteristics, and the amount of garlic added to Kimchi influenced the sourness, sweetness and fresh flavor, irrespective of the kinds of Kimchi and fermentation temperature.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1193-1198
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• 2003

The effects of preferment levels prepared with lactic acid bacteria isolated from kimchi on the quality of white pan bread were studied. The aim was to investigate how preferment influenced the baking-technological, textural, and sensory properties of white pan bread. During the process of making white pan bread, the pH decreased as the preferment levels increased, whereas the titratable acidity increased. The loaf specific volume increased from 4.66 to $5.59\;cm^3/g$ as preferment content increased from $10%{\sim}25%$. The moisture content and water activity of the bread ranged from 40.77 to 41.49%, and 0.961 to 0.966, respectively, indicating that no appreciable differences were related with the preferment levels (p<0.05). The textural characteristics of white pan bread were highly correlated with the amount of preferment added. White pan bread containing preferment showed a decrease in hardness and gumminess, and an increase in springiness. The color of white pan bread was not significantly different from that of the control. In sensory evaluation, the values for volume, springiness, and umami were highest in the white pan bread with 20% preferment, and the sour and umami tastes increased with the amount of preferment.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.349-354
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• 2017

The geographical origins of raw ginseng (RG) were discriminated using an electronic tongue. Taste screening, DFA (discriminant function analysis), and CDA (canonical discriminant analysis) were used to statistically analyze the data. The taste profile patterns of umami, bitterness, and sweetness of the Korean RG was different from those of the Chinese RG. The Korean RG was stronger than the Chinese RG regarding the taste of umami. DFA discriminated the geographical origins of 154 samples, with a few overlapping samples, between the Korean and Chinese RG. CDA showed that the accuracy of origin discrimination for the Korean and Chinese RGs were 87.01 and 94.81%, respectively. The final accuracy of origin discrimination was 90.91%. The distance between the centroids of each group was 2.7463. Thus, the electronic tongue analysis can be used to efficiently differentiate the geographical origins of RG.

• Food Engineering Progress
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• v.15 no.3
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• pp.243-249
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• 2011

Optimum conditions to prepare a yeast extract with rice protein hydrolysates(rh) were investigated. The yeast extract was obtained at the level of 2.3 g/L from the yeast culture medium($30^{\circ}C$, 48 hr) composed of 5% rh and glucose( 3%, w/w). Within the extract, RNA was contained at the level of 188.1 mg/g and the levels of GMP and IMP as nucleotides were $650.33{\pm}48{\mu}g/g$, $69{\pm}21{\mu}g/g$, respectively. When Rrh(Residual rice protein hydrolysate by $Delvolase^{(R)}$) was supplemented into a yeast extract, the savory taste like umami of the mixture was found to increase noticeably based on the measurements by taste sensing system as well as sensory test. It is assumed that soluble peptides in Rrh could play an important role in improving the overall taste of yeast extract by enhancing its umami taste. Therefore, the yeast extract supplemented with Rrh could be used for manufacturing a high value-added natural seasoning ingredient.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.30 no.4
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• pp.165-171
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• 2019

The objective of this study was to investigate the effects of gender on meat quality traits and sensory characteristics of pork loin. A total of 90 pork carcasses (180 days old, 45 barrows and 45 gilts, each gender group was consisted of fifteen 1+, 1 and 2 carcass grades) were selected and loin cuts were excised to investigate meat quality, electronic tongue measures and sensory panel test. There were significant differences in drip loss (1.66% vs 1.21%), released water (12.19% vs 10.68%) and cooking loss (23.67% vs 21.04%) between loins from barrow and gilt (p<0.05). However, no significant differences in meat color (CIE L^* a^* b^*) and shear force were observed between gender groups (p>0.05). Umami and richness values of barrow were significantly higher than those of gilt, while barrow had significantly lower sourness value compared to gilt(p<0.05). On the sensory evaluation, barrow scored higher in flavor, juiciness and tenderness both, and as a result, barrow (5.51 points) also scored significantly higher than gilt (4.86 points). These results suggest that the umami intensity and sensory taste of barrow loin are superior to gilt loin due to its high water-holding capacity.