• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.143-146
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• 2006

Effects of licorice (Glycyrrhiza uralensis) powder as sugar substitute on kimchi quality was evaluated by investigating acid formation, lactic acid bacteria growth, and sensory properties of licorice powder added kimchi. Initial pH of licorice powder added kimchi unripened and ripened for one day did not differ from those of other samples, but slightly increased thereafter 2-3 days ripening. Acidities of unripened and kimchi ripened for 1 day significantly increased by addition of licorice powder, while that of kimchi ripened for 2-3 days significantly decreased (p<0.05). Addition of licorice powder had no significant effect on lactic acid bacteria count of kimchi compared to sugar. Overall acceptability and taste of 0.1 and 0.2% licorice powder-added kimchi ripened for 1-3 days were similar to or slightly higher than those of reference sample, whereas addition of 1.0% licorice powder resulted in lowest overall acceptability, taste, odor, and texture. Licorice powder addition generally did not change color of kimchi.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.375-385
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• 2020

The purpose of this study was to investigate the quality characteristics of kimchi prepared with a single starter culture of biogenic amines (BA)-forming lactic acid bacteria (LAB) or a combined starter cultures composed of BA-forming and BA-degrading LAB. As the fermentation proceeded, the lactic acid bacterial count, titratable acidity, and BA content in kimchi prepared with myeolchi-aekjeot were slightly higher than those of kimchi prepared with saeu-jeot. The amount and type of BA produced by LAB were mostly strain dependent rather than species specific. Among all of the isolated LAB strains, the highest levels of cadaverine, histamine, putrescine and tyramine were produced by Leuconostoc mesenteroides MBK32, Lactobacillus brevis MBK34, Lactobacillus curvatus MBK31 and Enterococcus faecalis SBK31, respectively. BA-forming and BA-degrading starter cultures played an important role in the growth rate and organic acid-producing ability of LAB in kimchi. Interestingly, BA contents in kimchi increased by adding single BA-forming LAB starter were effectively lowered by the mixed cultures with BA-degrading LAB.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.125-134
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• 2024

In this research, the growth efficiency, nutritional utilization, fecal microbial levels, and fecal score of weaned pigs were evaluated using therapeutic zinc oxide (ZnO) and zinc aspartic acid chelate (Zn-Asp). In a 42-day feeding trial, 60 weaned pigs ([Yorkshire × Landrace] × Duroc) were arbitrarily allotted (age: 21 days; 7.01 ± 0.65 kg preliminary body weight) to 3 different treatment groups with 5 repetitions (2 male and 2 female piglets) in each pen. The trial had 2 different phases, including 1-21 days as phase 1, and 22-42 days as phase 2. The nutritional treatments were: basal diet as control (CON), basal diet incorporated with 3,000 ppm ZnO as TRT1, and basal diet incorporated with 750 ppm Zn-Asp as TRT2. In comparison to the CON group, the pigs in the TRT1 and TRT2 groups had greater (p < 0.05) body weight on day 42; an average daily gain, and an average daily feed intake on days 22-42. Furthermore, during days 1-42, the average daily gain in the treatment groups trended higher (p < 0.05) than in the CON group. Additionally, the fecal score decreased (p < 0.05) at week 6, the lactic acid bacteria count tended to increase (p < 0.05), and coliform bacteria presented a trend in reduction (p < 0.05) in the TRT1 and TRT2 groups compared to the CON group. However, there was no difference in nutrient utilization (p > 0.05) among the dietary treatments. Briefly, the therapeutic ZnO and Zn-Asp nutritional approaches could decrease fecal score and coliform bacteria, increase lactic acid bacteria, and improve growth efficiency; moreover, Zn-Asp (750 ppm) can perform a comparable role to therapeutic ZnO (3,000 ppm). So we can use Zn-Asp (750 ppm) instead of therapeutic ZnO (3,000 ppm) for the better performance of weaning pigs and the reduction of environmental pollution, as therapeutic ZnO is responsible for environmental pollution.

• Journal of Food Hygiene and Safety
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• v.34 no.6
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• pp.591-594
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• 2019

Some strains of Escherichia coli are categorized as pathogenic bacteria and alternative antimicrobials including bacteriophages for controlling these bacteria have been studied. In this study we screened antimicrobial candidates that present synergistic inhibition of the growth of E. coli DH5α as a model when co-treated with the bacteriophage ECP27 to target the bacteria. As candidates, CaCl₂, lactic acid, and citric acid were tested. CaCl₂ showed a synergistic inhibition against the strain by dose-dependent manner at 6 h of incubation but the viable cell count was recovered at 12 h. However, lactic acid and citric acid at 30 mM concentration showed synergistic inhibitions at 6 h of incubation and cleared the viable cells of E. coli DH5α at 12 h when co-treated with the bacteriophage even though lactic acid or citric acid alone was effective. Therefore, co-treatment using the bacteriophage and organic acids such as lactic acid and citric acid can be a solution for synergistic inhibition of the growth of E. coli.

• Food Science and Preservation
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• v.24 no.3
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• pp.387-393
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• 2017

The objective of this study was to investigate the effect of hot water extract of Welsh onion root (HEWO) on growth of lactic acid bacteria and fermentative characteristics of yogurt. The physiochemical characteristics of HEWO such as pH, soluble solid, reducing sugar, total polyphenol content and DPPH radical scavenging activity were studied. The lactic bacterial count in brain heart infusion (BHI) broth with HEWO was about 1 log cycle higher than in control for 24 h at $37^{\circ}C$. The pH of yogurt prepared with HEWO (WY100) and 50% HEWO (WY50) was gradually decreased significantly but increased the viscosity of yogurt with increasing HEWO concentration during fermentation. The viable cells of lactic acid bacteria after fermentation for 24 h were 8.03 (control), 8.77 (WY50), 8.84 (WY100) log CFU/mL, respectively. The DPPH radical scavenging activity of yogurt increased with increasing HEWO concentration. Sensory quality of yogurt prepared with HEWO was higher than that of control. The pH and lactic acid bacteria of all tested yogurts decreased during storage for 10 days at $4^{\circ}C$ but lactic bacterial count of yogurt prepared with HEWO maintained $10^8CFU/mL$ during storage. These results indicated the potential use of HEWO as a valuable resource to improve fermentation and functionality of yogurt.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.100-110
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• 2020

Objective: The objective of this study was to isolate proteolytic microorganisms and evaluate their effects on proteolysis in total mixed ration (TMR) silages of soybean curd residue. Methods: TMRs were formulated with soybean curd residue, alfalfa or Leymus chinensis hay, corn meal, soybean meal, a vitamin-mineral supplement, and salt in a ratio of 25.0: 40.0:30.0:4.0:0.5:0.5, respectively, on a basis of dry matter. The microbial proteinases during ensiling were characterized, the dominate strains associated with proteolysis were identified, and their enzymatic characterization were evaluated in alfalfa (A-TMR) and Leymus chinensis (L-TMR) TMR silages containing soybean curd residue. Results: Both A-TMR and L-TMR silages were well preserved, with low pH and high lactic acid concentrations. The aerobic bacteria and yeast counts in both TMR silages decreased to about 10⁵ cfu/g fresh matter (FM) and below the detection limit, respectively. The lactic acid bacteria count increased to 10⁹ cfu/g FM. The total microbial proteinases activities reached their maximums during the early ensiling stage and then reduced in both TMR silages with fermentation prolonged. Metalloproteinase was the main proteinase when the total proteinases activities reached their maximums, and when ensiling terminated, metallo and serine proteinases played equally important parts in proteolysis in both TMR silages. Strains in the genera Curtobacterium and Paenibacillus were identified as the most dominant proteolytic bacteria in A-TMR and L-TMR, respectively, and both their proteinases were mainly with metalloproteinase characteristics. In the latter ensiling phase, Enterococcus faecium strains became the major sources of proteolytic enzymes in both TMR silages. Their proteinases were mainly of metallo and serine proteinases classes in this experiment. Conclusion: Proteolytic aerobic bacteria were substituted by proteolytic lactic acid bacteria during ensiling, and the microbial serine and metallo proteinases in these strains played leading roles in proteolysis in TMR silages.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.226-230
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• 2001

High hydrostatic pressure was applied to Foxtail Millet Takju to investigate the effects of high pressure on inactivation of microorganisms and enzymes. Total bacteria, lactic acid bacteria and yeast in untreated Takju were $6.8{\times}10^7,\;1.3{\times}10^8\;and\;8.4{\times}10^7\;CFU/mL$, respectively. Total bacterial count in Takju reduced to $2.2{\times}10^5\;CFU/mL$, while lactic acid bacteria and yeast were sterilized completely when heated at $65^{\circ}C$ for 30 min. Lactic acid bacteria and yeast decreased with the increase of treatment pressure, and pressurization of 400 MPa for 10 min at room temperature sterilized completely the lactic acid bacteria and yeast in Takju. Total bacteria were not sterilized with pressurization of even 600 MPa at room temperature. Total bacteria were completely sterilized at $66^{\circ}C/400\;MPa/60\;min\;and\;66^{\circ}C/600\;MPa/10\;min$. Pressurization of Takju caused a partial inactivation of ${\alpha}-amylase$, and after pressurization at 600 MPa for 10 min at room temperature, 73.2% of the original activity remained. The activity of glucoamylase increased with the increase of treatment pressure. Treatment at $66^{\circ}C/400\;MPa/10\;min$ reduced the activity of ${\alpha}-amylase$ by 59.7% and glucoamylase by 20.5%. ${\alpha}-Amylase$ was inactivated to less than 1.2% of the original activity at $66^{\circ}C/600\;MPa/30\;min$.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.421-429
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• 2019

Objective: In this study, the effects of vacuum (VP) and high-oxygen modified atmosphere ($80%\;O_2+20%\;CO_2$) packaging (HiOx-MAP) on physico-chemical and microbiological properties of minced water buffalo meat were investigated. Methods: After minced meat preparation, samples were packaged under VP and HiOx-MAP and stored at $2^{\circ}C{\pm}0.5^{\circ}C$ for 14 days. Samples taken on certain days were subjected to total aerobic mesophilic bacteria, total aerobic psychrotrophic bacteria, lactic acid bacteria, Pseudomonas, Enterobacteriaceae and yeast-mold counts as well as pH, color ($L^*$, $a^*$, and $b^*$) and thiobarbituric acid reactive substances (TBARS) analyses. Results: In minced water buffalo meat packaged under HiOx-MAP, TBARS value exceeded 1 mg malondialdehyde/kg on the 4th day of the storage. In VP samples, TBARS value remained close to initial TBARS value during storage. According to the findings, $a^*$ value was determined to be high in the HiOx-MAP samples within initial days of the storage. However, no significant changes in $a^*$ value were observed in VP samples during storage. In contrast, the mean value of $L^*$ was detected as higher in HiOx-MAP sample than VP samples. The count of psychrotrophic bacteria increased more than that of mesophilic bacteria during storage. The growth of Enterobacteriaceae and Pseudomonas was delayed in both the packaging methods. However, lactic acid bacteria exhibited more growth in VP samples compared to MAP samples. Conclusion: The lipid oxidation proceeded faster than expected in minced water buffalo meat packed with HiOx-MAP method. This situation adversely affected the $a^*$ value. On the other hand, similar microbiological results were obtained in both packing methods.

• Journal of Life Science
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• v.31 no.4
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• pp.367-376
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• 2021

This study evaluated the changes in the pH, acidity, lactobacillus and total bacterial counts, and sensory evaluation of Dolsan leaf mustard Kimchi (DLMK) after incubation for 50 days at 4℃ in the presence of one of three lactic acid bacteria (LAB); Weissella kimchii (W.k.), Leuconostoc gelidum (L.g.), and Leuconostoc mesenteroides (L.m.). The pH ranged from 5.12 to 5.62 and the acidity varied from 0.62% to 3.77% upon the addition of a 2% salt solution to the DLMK prepared using the three LAB. Overall, the LAB counts decreased rapidly from day 10 to day 20 of fermentation, whereas the total bacterial count decreased during the 50 days of fermentation. The pH and acidity in the DLMK ranged from 5.22 to 5.61 and from 0.91% to 4.41%, respectively, in the absence of the 2% salt solution. The LAB count decreased until 20 days and then increased thereafter, whereas the total bacterial count decreased until 20 days and then increased until 50 days. The condiments treated with or without the 2% salt solution showed a gradual decrease in appearance, flavor, salinity, hot taste, and overall acceptability as fermentation time increased. In addition, DPPH radical scavenging activity was high for 2% W. k. and 2% L. m., and ACE inhibitory activity was the highest, at 70.38% in the marinated condiments fermented at 10℃ for 8 days. Thus, this condiment production method may be useful for DLMK and other Kimchi types.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.144-147
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• 2006

This experiment was carried out to investigate the effect of mulberry fruit extinct on the acid production and growth of lactic acid bacteria. The extract of mulberry fruit was showed a high level of yield with 60% ethanol extraction. Lactic acid bacteria was used in a starter culture of Lactobacillus casei YIT9018 and 2782, and Lactobacillus acidophilus NCFM. After 24 hr culture in MRS broth added with 1.0, 5.0 and 10% of the extract 1.0% addition of the extract was showed pH $4.04{\sim}4.19$, titratable acidity $1.25{\sim}1.42%,\;and\;1.2{\sim}7.8{\times}10^9\;cfu/mL$ of viable cell count. The additions above 1.0% extract (5.0% and 10.0% addition) showed slightly lower effect than 1.0% addition. However, the addition of the extract showed a high effect on the growth of lactic acid bacteria comparing with the control. In yoghurt preparation with the extract, 1% addition of the extract showed a high effect on the growth of lactic acid bacteria, Therefore, it was suggested to manufacture of the yoghurt with the addition of 1% mulberry fruit extract and the inoculation of culture of Lactobacillus acidophilus for on the stimulation of growth of the lactic culture.