• Korean journal of food and cookery science
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• v.2 no.2
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• pp.1-7
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• 1986

Gulbi were made by salting Yellow corvenia (Pseudosciaena manchurica) with the in three ways: the dry salting method with bay salt, the dry salting method with purified salt or with the abdominal brine injection method with purifie salt. The half of the sample was dried by the control system of temperature and humidity: the other part was dried by the natural condition. In fresh muscle, the content of IMP, hypoxanthine, inosine and AMP were $13.40,\;9.28,\;3.01{\mu}mole/g$ and trace amount, dry basis, respectively. In fresh egg, the content of AMP, hypoxanthine, inosine and IMP were 13.98, 6.56, 1.98 and $1.93{\mu}mole/g$, dry basis, respectively. During the drying process of Yellow corvenia, the content of hypoxanthine increased remarkably, while the content of AMP, IMP and inosine decreased ana remained as trace amount. It can be suggested that the characteristic flavor of Gulbi is not attributed to the nucleotides and their related compounds but rather to free amino acids.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.603-610
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• 2001

The quality characteristics of soy yogurt prepared with different proteolytic enzymes and starter culture were evaluated. In order to facilitate the growth of lactic acid bacteria and subsequent production of lactic acid, soy protein isolate(SPI) was hydrolyzed using three kinds of proteases; one extracted from Aspergillus oryzae, bromelain and ${\alpha}-chymotrypsin$. The cultural systems employed thereafter for lactic fermentations were: 1) Bifidobacterium bifidum, 2) B. bifidum and Lactobacillus acidophilus, 3) B. bifidum and Lactobacillus bulgaricus. In soy yogurt, pH was more decreased by mixed culture method than single culture method with the accumulation of lactic acid. Viable cells of lactic acid bacteria in soy yogurts were measured $10^8$ CFU/g by the single culture method while $10^9$ CFU/g by the mixed culture method except ${\alpha}-chymotrypsin$ treatment. The amount of free amino acids in soy yogurts were substaintially increased by enzyme treatment. Viscosity was decreased by enzyme treatment, resulting in higher viscosity by ${\alpha}-chymotrypsin$ treatment. Water holding capacity was found to be higher in the single culture method in case of enzyme treatment. Among the various volatile flavor components isolated and identified after enzyme hydrolysis, acetaldehyde, ethanol, diacetyl, butyl alcohol contents tended to increase by lactic fermentation.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.665-670
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• 2018

This study was designed to evaluate the physicochemical properties and biological activities (antioxidant activity and antimicrobial activities) of three and seven-year-old Platycodon grandiflorum extracts. Three and seven-year-old Platycodon grandiflorum contained crude saponins, free amino acids and minerals. Water extracts of the three and seven-year-old plants were prepared using reflux extraction methods. The total polyphenol contents (TPC), total flavonoid contents (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity and antimicrobial effects of the extracts were determined. The seven-year-old Platycodon grandiflorum extract had higher TPC ($5.08{\pm}0.07TAEmg/g$) and TFC ($3.80{\pm}0.07QUEmg/g$). DPPH radical scavenging activity ($IC_{50}$ value: $288{\pm}3.88{\mu}g/mL$) and ABTS radical scavenging activity ($IC_{50}$ value: $568{\pm}2.09{\mu}g/mL$). The three and seven-year-old Platycodon grandiflorum extracts exhibited a strong antimicrobial effect against three kinds of bronchus disease-inducing bacteria; the seven-year-old Platycodon grandiflorum extracts showed a stronger antimicrobial effect than the three-year-old Platycodon grandiflorum extracts.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.217-223
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• 2019

This study aimed to evaluate the characteristic differential between whole cabbage kimchi (pogi kimchi) and sliced cabbage kimchi (mat kimchi) during kimchi fermentation at $6^{\circ}C$. The difference of microbial and physicochemical properties was investigated until 6 weeks. For the changes in the microbial flora, both kimchi samples exhibited a continuous increase in total aerobic bacteria and lactic acid bacteria (LAB) population size up to 2 weeks followed by a stationary phase until 5 weeks. Interestingly, the number of LAB of mat kimchi was overall higher than that of pogi kimchi during kimchi fermentation. We speculate that mat kimchi has in a more advantageous growth condition than pogi kimchi for microbial growth because small kimchi cabbage size appropriately derives nutritional supply in order to increase the LAB growth. During lactic fermentation at $6^{\circ}C$, physicochemical changes in the pH, salinity, and titratable acidity was observed to be no significant differences between two types of kimchi. Furthermore the contents of organic acids such as oxalic acid, citric acid, malic acid, lactic acid, fumaric acid, and acetic acid was not significantly different (p>0.05) between both kimchi samples as well as the contents of total free amino acid.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.239-253
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• 2021

This study investigates the metabolomic changes in breast and thigh meat from Cobb and Ross 308 chickens regarding the rearing environment. One-day-old Cobb and Ross broilers were raised for 35 days in conventional and animal welfare farms with, amongst others, different floor sizes, stock densities, and ammonia concentrations. One-dimensional ¹H nuclear magnetic resonance, orthogonal partial least squares-discriminant analysis (OPLS-DA), and pathway analyses were performed to analyze the metabolomic properties of broiler meat. For breast meat, only those from the Ross strain could be separated according to the environment in the OPLS-DA plot. Ross breast meat from animal welfare farms showed significantly higher acetate, anserine, creatine, and inosine monophosphate content than those from conventional farms (P<0.05). In contrast, for thigh meat, the Cobb strain was differentiated using OPLS-DA. The contents of five metabolites, such as glucose and lactate, were higher in thigh meat from animal welfare farms; however, nine metabolites, including seven free amino acids, were lower compared to those from conventional farms (P<0.05). Pathway analysis was performed to interpret the biological changes in chicken meat based on environmental factors. The results indicated that the animal welfare environment led to significant changes in four metabolic pathways in Ross breast meat and in 20 metabolic pathways in Cobb thigh meat (P<0.05). In conclusion, the animal welfare environment could influence the metabolomic properties of Ross breast meat and Cobb thigh meat, which may affect the sensory quality of meat.

• Journal of Life Science
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• v.33 no.1
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• pp.8-14
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• 2023

Peroxidasin (PXDN), a multidomain heme peroxidase containing extracellular matrix (ECM) motifs, as well as a catalytic domain, catalyzes the sulfilimine crosslink of collagen IV (Col IV) to reinforce Col IV scaffolds. We previously reported that PXDN is required for endothelial cell (EC) survival and growth signaling through sulfilimine crosslink-dependent matrix assembly. In this study, we examined whether peroxidase activity is required for PXDN function in ECs. First, we constructed a mutant PXDN by point mutation of two highly conserved amino acids, Q823 and D826, which are present in the active site of the peroxidase domain. After isolation of HEK293 clones highly expressing the mutant protein, conditioned medium (CM) was obtained after incubating the cells in serum-free medium for 24 hours and then analyzed by Western blot analysis under nonreducing conditions. The results revealed that the mutant PXDN formed a trimer and that it was cleaved by proprotein convertase-like wild-type (WT) PXDN. However, peroxidase activity was not detected in the CM containing the mutant PXDN, in contrast to that of WT PXDN. In addition, the sulfilimine crosslink ability of the mutant PXDN was lost. Moreover, the CM containing the mutant PXDN failed to promote the growth of PXDN-depleted ECs, unlike the CM containing WT PXDN. These results suggest that the peroxidase activity of PXDN affects EC growth by forming a sulfilimine crosslink.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.1040-1052
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• 2023

The objective of this study was to investigate the protective effects of functional nutrients including various functional amino acids, vitamins, and minerals on chicken intestinal epithelial cells (cIECs) treated with oxidative stress. The cIECs were isolated from specific pathogen free eggs. Cells were exposed to 0 mM supplement (control), 20 mM threonine (Thr), 0.4 mM tryptophan (Trp), 1 mM glycine (Gly), 10 μM vitamin C (VC), 40 μM vitamin E (VE), 5 μM vitamin A (VA), 34 μM chromium (Cr), 0.42 μM selenium (Se), and 50 μM zinc (Zn) for 24 h with 6 replicates for each treatment. After 24 h, cells were further incubated with fresh culture medium (positive control, PC) or 1 mM H₂O₂ with different supplements (negative control, NC and each treatment). Oxidative stress was measured by cell proliferation, whereas tight junction barrier function was analyzed by fluorescein isothiocyanate (FITC)-dextran permeability and transepithelial electrical resistance (TEER). Results indicated that cell viability and TEER values were less (p < 0.05) in NC treatments with oxidative stress than in PC treatments. In addition, FITC-dextran values were greater (p < 0.05) in NC treatments with oxidative stress than in PC treatments. The supplementations of Thr, Trp, Gly, VC, and VE in cells treated with H₂O₂ showed greater (p < 0.05) cell viability than the supplementation of VA, Cr, Se, and Zn. The supplementations of Trp, Gly, VC, and Se in cells treated with H₂O₂ showed the least (p < 0.05) cellular permeability. In addition, the supplementation of Thr, VE, VA, Cr, and Zn in cells treated with H₂O₂ decreased (p < 0.05) cellular permeability. At 48 h, the supplementations of Thr, Trp, and Gly in cells treated with H₂O₂ showed the greatest (p < 0.05) TEER values among all treatments, and the supplementations of VC and VE in cells treated with H₂O₂ showed greater (p < 0.05) TEER values than the supplementations of VA, Cr, Se, and Zn in cells treated with H₂O₂. In conclusion, Thr, Trp, Gly, and VC supplements were effective in improving cell viability and intestinal barrier function of cIECs exposed to oxidative stress.

• Food Science and Preservation
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• v.20 no.6
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• pp.818-826
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• 2013

To evaluate the practical use of okara koji in soy sauce fermented with soybean koji, the okara koji was fortified with different contents (0, 50, and 100%) in soybean koji and then fermented for 90 days. The saltiness of the soy sauce was about 17.15~17.22%. The higher okara koji content showed lower net soluble solid contents of 8.73, 6.12, and 2.50%, as well as lower acidity levels of 1.09, 0.98, and 0.47%. The buffering capacity of the soy sauce decreased to 1.26-3.41 by adding higher okara koji. The protease activity was higher in the soy sauce with 50% orara koji and decreased with longer fermentation. Also, the tyrosine content peaked to 275.2 mg% after 90 days. ${\alpha}$-amylase showed higher activity in the soy sauces fortified with okara koji, which resulted in the highest total sugar and reducing sugar contents after 60 days. The total sugar and the reducing sugar in the soy source decreased after longer fermentation. The total free amino acid contents of the soy sources fortified with okara koji (0, 50, and 100%) were 41.68 mg/mL, 33.10 mg/mL, and 9.27 mg/mL, respectively. In particular, the glutamic acid contents of the three types of soy sauces were highest, and most amino acids, except for glutamine, increased during the fermentation for 90 days. The sensory evaluation, except of the saltiness and color, showed similar values in the soy sauces, except in the okara koji 100%. Thus, okara koji could be a valuable ingredient of traditional soy sauces. However, the 50% okara koji did not differ significantly from the others.

• Food Science and Preservation
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• v.15 no.2
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• pp.174-184
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• 2008

The quality and storage characteristics of low salted onion and five cereals-doenjang (DFO) were investigated. At the DFO, soybean koji ($57{\sim}62%$), onion (3%) and salt (8%) were mixed with equal amount of rice, barley, glutinous millet and glutinous indian millet ($10{\sim}30%$), and water ($7{\sim}12%$). The storage of DFO was done by vacuum packing in polypropylene tube, and sterilized at $121^{\circ}C$. The fermentation and storage was conducted for 60 days at $25^{\circ}C$ at each condition. Control doenjang (GD) was the salinity of 16% soybean doenjang that was not sterilized and packed in plastic containers for storage. During the fermentation, pH of DFO was lower than GD. The pH maintained stability during the storage, and revealed to be lowered, as the proportion of mixed cereals was higher. During the fermentation of DFO, the brix degree revealed to be higher than GD and maintained s1ability during the storage. During the fermentation and storage, the amino nitrogen content of DFO was ranged $400{\sim}470mg%$ by showing higher content than GD and maintained stable content during the storage. During the fermentation, the activities of protease and ${\beta}$-amylase were maintained to be high at DFO, but the activities during the storage were high at GD. The color $L^*$ value of DFO during fermentation and storage maintained higher values than GD, but $a^*$ value revealed lower pattern. Total free amino acids of DFO was ranged $1,918{\sim}2,290mg%$ which was higher than GD that recorded 1,291 mg%. When the sensory evaluation was conducted for DFO that was fermented and stored for 60 days, the DFO mixed with $20{\sim}30%$ of cereals resulted to have more savory taste, flavor, and sweeter than GD, and overall acceptability for color and overall taste was high.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.9-18
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• 2013

The aim of this study is to provide the basic data for yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson] in dietary food. The nutritional compositons, such as protein, ash, carbohydrate, dietary fiber, vitamin and fructooligosaccharide, were analyzed for 4 yacon germplasm lines. Yacon has low calories with only 46~56 kcal/100 g. The contents of water, fat, ash, protein, carbohydrate and dietary fiber were ranged 85.9~86.8%, 0.1~0.2%, 0.2~0.3%, 0.5~0.7%, 12.2~13.1% and 1.05~1.14%, respectively. The iodine-starch test did not show any color or precipitation reaction, which indicates that yacon has no starch content. However, in the absence of starch, yacon is rich in fluctooligosaccharide, which is between 9.6~11.1%. Maltose is present in the larger amount, followed by sucrose, glucose, and fructose in terms of free sugars. The analysis of minerals revealed that yacon contains potassium in the larger amount of 141~176 mg/100 g F.W., followed by magnesium at 8.2~10.6 mg, calcium, and sodium representing the least present mineral. Yacon proved to have a total of 17 types of amino acids, which are between 404.0~581.8 mg per 100 g of yacon. Glutamic acid, the main sweetening component, is present in the large amount of 94.0~182.2 mg/100 g F.W., followed by aspartic acid, arginine, and alanine. The proportion of the essential amino acid was 24.8~33.6%. Results of analysis also showed that yacon contains 0.001~0.024 mg, 0.03~0.11 mg, 0.02~0.3 mg, 0.3~0.4 mg and 14.1~20.6 mg of ${\beta}$-carotene, thiamin, riboflavin, niacin, and ascorbic acid, respectively. It is also likely to be highly used as functional food material in the future because it is abundant in both fluctooligosaccharide and antioxidants which are important functional components.