• Food Science of Animal Resources
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• v.29 no.2
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• pp.269-277
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• 2009

This paper reports the results of the research on the effects of probiotic yogurt on the microbiological quality, pH, and sensorial characteristics of fresh chicken meat when packed with probiotic yogurt. The chicken meat pieces were packed with yogurt and were stored at $10^{\circ}C$ for 7 days. Samples were taken after 0, 2, 4, and 7 days of storage, and were analyzed for total bacterial count, E. coli, and coliform, and for the chemical parameters, including the pH. In the control group (packed without yogurt), the Pseudomonas species predominated when the spoilage was obvious after 4-day storage at $10^{\circ}C$. The yogurt-mixed chicken meat package was found to have a significantly lower total viable count and significantly fewer coliform bacteria during storage. Furthermore, the yogurt package showed a growth-inhibiting effect on the Salmonella typhimurium, which were inoculated into the chicken meat pieces for the study. The study findings indicate that probiotic yogurt can be used in packing fresh chicken meat to decrease the population of spoilage bacteria therein and to extend its shelf life.

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.397-398
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• 2009

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.211-219
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• 2019

The effect of microencapsulation on previously isolated Lactobacillus delbrueckii 94/L4 as starter culture for yogurt, and Lactobacillus casei 97/L3 as a probiotic candidate was investigated. Preliminary results showed that L. delbrueckii 94/L4 exhibited tolerance to bile, unlike L. casei 97/L3. Freeze drying significantly (p < 0.05) reduced the viability of both isolates by log 0.71-2.70. Although microencapsulation preserved the viability of L. casei 97/L3 cells exposed to simulated gastrointestinal tract conditions for 120 min, it did not impart significant (p < 0.05) protection against loss of viability during the first 30 min of exposure. Conversely, microencapsulated L. delbrueckii 94/L4 with the addition of Streptococcus thermophilus 24/S1 as starter culture was successfully incorporated into milk to form yogurt, yielding a significantly (p < 0.05) improved product quality.

• Journal of Dairy Science and Biotechnology
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• v.38 no.3
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• pp.154-160
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• 2020

Physical and sensory characteristics of commercial yogurts are important aspects for consumer acceptability. In addition, beneficial functions of commercial yogurts are also emphasized for the probiotic dairy products. The aim of this study was to investigate the functional properties of yogurts with the combination of bacteriocin-producing Pediococcus acidilactici. Yogurts fermented with commercial starter culture (control yogurt) and control yogurt together with P. acidilactici HW01 (yogurt+HW01), P. acidilactici JM01 (yogurt+JM01), or P. acidilactici K10 (yogurt+K10) were prepared. During 28 days after fermentation, the viability of lactic acid bacteria, pH, and brix, in the yogurt samples were assessed with standard methods. Moreover, to investigate the antilisterial activity of the yogurt samples, Listeria monocytogenes was simultaneously inoculated when the yogurts were prepared with lactic acid bacteria, and the viability of L. monocytogenes was determined. Although yogurt+K10 did not completely remove L. monocytogenes, control yogurt, yogurt+HW01, and yogurt+JM01 eradicated L. monocytogenes at day 2 after fermentation. However, yogurt+K10 also removed L. monocytogenes at day 3 after fermentation. Taken together, these findings suggest that the combination of yogurt with P. acidilactici does not affect its quality and they may consequently aid in the development of new probiotic yogurt.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.276-286
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• 2020

Probiotics are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. This study was conducted for the isolation of potential lactic acid bacteria (LAB) with probiotic properties from goat milk and yogurt. Several tests were conducted in vitro using the standard procedures for evaluating the inhibitory spectra of LAB against pathogenic bacteria; tolerance to NaCl, bile salt, and phenol; hemolytic, milk coagulation, and bile salt hydrolase activities; gastrointestinal transit tolerance; adhesion properties; and antibiotic susceptibility. Among 40 LAB strains screened according to culture characteristics, five isolates exhibited antagonistic properties. Three were identified as Pediococcus acidilactici, and two were identified as Enterococcus faecium, exploiting 16S rRNA gene sequencing. All the isolates succeeded in the gastrointestinal transit tolerance assay and successively colonized mucosal epithelial cells. Based on the results of these in vitro assays, both P. acidilactici and E. faecium can be considered as potential probiotic candidates.

• Food Science of Animal Resources
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• v.35 no.3
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• pp.339-349
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• 2015

The objective of this study was to identify lactic acid bacteria (LAB) isolated from kimchi and to evaluate its characteristics and functional properties for application in fermented dairy products as a probiotic or commercial starter culture. Eight stains isolated from kimchi were selected through an investigation of phenotypic characteristics. Two strains (DK211 and DK303) were identified as Lactobacillus plantarum, another two (DK207 and DK215) as Lactobacillus paracasei, and one (DK301) as Lactobacillus sakei. The remaining three strains were identified as species of Weissella. All selected Lactobacillus strains had acid and bile tolerance, even though there was wide variation in the ability of each strain. DK303 showed a remarkably higher proteolytic activity. There were no significant differences in β-galactosidase activity among the tested strains, except that DK301 showed no activity. Auto-aggregation varied between 82.1 and 90.0%, and hydrophobicity values ranged from 0.5 to 51.6%.The strongest auto-aggregation and hydrophobicity were observed in DK211. All selected strains showed better 1,1-diphenyl-2-picrylhydrzyl (DPPH) scavenging activity than commercial strains. DK211, DK215, DK301, and DK303 had effective inhibitory activity against all pathogens tested except E. coli. When selected strains were used for yogurt preparation as a single starter culture, the time required to reach target titratable acidity (0.9) was 11-12 h. The yogurt fermented with DK211 had favorable panelists ratings for most sensory attributes, which were comparable with yogurt fermented with a commercial strain. The results suggest that strains isolated from kimchi could be potential probiotic and starter cultures for use in yogurt manufacturing.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.133-138
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• 2001

In this study, an attempt was made to increase the survival rate of bifidobacteria entrapped in alginate in the gastrointestinal tract, and to investigate the potential industrial applications, for example lyophilized capsules and yogurt. First, the protective effect of various food additives on bifidobacterial survivability was determined after exposure to simulated gastric juices and bile salts. The additives used in this study were skim milk (SM), polydextrose (PD), soy fiber (SF), yeast extract (YE), chitosan (CS), $\kappa$-carageenan ($\kappa$-C) and whey, which were added at 0.6% concentration (w/v) to 3% alginate-bifidobacterial solution. In the simulated gastric juices and bile salts, the protective effect of 0.6% skim milk-3% alginate (SM-A) beads on the survival rate of bifidobacteria proved to be higher than the other additives. Second, the hydrogen ion permeation was detected through SM-A vessel without bifidobacterial cells at different SM concentrations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). There were no differences in terms of the pH decrease in SM-A vessels at 0.6%, 0.8%, and 1.0% (w/v) SM concentrations. The survival rate of bifidobacteria in SM-A beads would appear to be related to the SM buffering capacity against hydrogen ions and its tendency to reduce the pore size of bead. In this experiment, the survival rate of bifidobacteria entrapped in beads containing 0.6% SM showed the highest viability after exposure to simulated gastric juices for 3h, thereby indicating that 0.6% SM is the optimum concentration fir 3% alginate bead preparation. Third, the effect of SM-A beads on the freeze-drying and yogurt storage for 10 days was investigated. SM-A beads were found to be more efficient for freeze drying and yogurt storage than untrapped cells and the alginate bead. Consequently, the survival rate of bifidobacteria entrapped in SM-A beads was increased in simulated gastric juices, bile salts and probiotic products, such as lyophilized capsules and yogurt, SM-A beads can be expected to produce high value probiotic products.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.231-240
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• 2016

The purpose of this study was to investigate the effect of exopolysaccharide (EPS)-producing Leuconostoc and Weissella isolates from kimchi as a probiotic starter and replacement for thickening agents such as pectin and gums in yogurt. Potential probiotic isolates were first screened for their acid and bile tolerance, and then evaluated for antimicrobial activity against Escherichia coli and Salmonella Typhimurium. When the selected Leuconostoc or Weissella isolates were co-inoculated in yogurt without a thickening agent, the yogurt with 4% sucrose produced lower syneresis values than the control and had higher EPS yields. The isolates were able to survive at a level of $10^6CFU/mL$ when incubated at $4^{\circ}C$ for 12 days. This study shows that EPS-producing Leuconostoc and Weissella strains have the potential to produce a synbiotic yogurt.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.556-565
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• 2014

In this study, we evaluated changes in physicochemical properties, total phenol and isoflavone contents, and antioxidant activity during soymilk fermentation by a potential probiotic Lactobacillus plantarum P1201. The P1201 strain showed survival rates of 58.14% and 62.22% after 4 h exposure to acid and artificial gastric acid conditions (pH 2.5), respectively. The optimal conditions for soy-yogurt fermentation by L. plantarum were determined to be as follows: temperature of $35^{\circ}C$, seed volume of 5.0%, and sucrose content of 10.0%. The total phenol and isoflavone contents and antioxidant activity were higher in soy-powder milk (SPM) yogurt than soymilk yogurt. In particular, the highest levels of isoflavone-aglycones, such as daidzein, glycitein, and genistein (91.50, 12.34, and $61.39{\mu}g/g$, respectively), were observed after 48 h of SPM fermentation. Thus, these results suggest that the soy-yogurt extract could be used as a potential source of natural antioxidants in food.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.820-830
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• 2019

Most consumers consider yogurt to be a healthy food because it contains probiotic microorganisms. Although a plethora of commercially produced yogurts exists, nutritional and functional aspects of the commercial yogurts have not been well characterized. In this study, the microbiological and physicochemical properties of popular drinking yogurts in Korea were extensively characterized. The viability of lactic acid bacteria, including lactobacilli and bifidobacteria, varied between yogurt samples. These lactobacilli and bifidobacteria showed effective antimicrobial activities against foodborne pathogenic bacteria. Unlike the titratable acidity and pH, the soluble solids content varied between yogurt samples. All the yogurt samples contained high levels of potassium (average 143.53 mg/100 g) and calcium (average 133.92 mg/100 g), as well as phosphorus and sodium. Lactose, fructose, and glucose were the major sugar components in most yogurt samples, whereas the levels of sucrose and maltose were relatively low. Among several organic acids analyzed in the yogurt samples, lactic acid (average 767.67 mg/100 g) and citric acid (average 170.91 mg/100 g) were the most predominant. Taken together, this study provides preliminary information about the nutritional and functional characteristics of commercially available drinking yogurts.