• Applied Biological Chemistry
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• v.27 no.3
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• pp.163-168
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• 1984

Soy yogurt beverage (SYB) was prepared from defatted soybean flour and flavor, effect of stabilizers on sedimentation and change of acidity and cell concentration during storage of SYB were investigated. The flavor of SYB rated significantly different and slightly inferior to milk yogurt although flavors added to SYB improved the acceptability. The curd in SYB precipitated greatly during the first 24 hours of storage. The sedimentation of curd was reduced by the addition of CMC of 0.4% or PGA of 0.1%. SYB can be kept at $5^{\circ}C$ for 48 days without significant change in viable cell count of lactic acid bacteria. pH, titratable acidity and viable cell count of SYB was significantly changed for 48 days at $25^{\circ}C$. Some of SYB samples were contaminated by yeast and mold.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.155-161
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• 2021

This study was conducted to estimate the effect of different cutting lengths on fermentation characteristics and aerobic stability of whole crop rice (WCR) silage. The WCR was harvested at the yellow ripe stage (43.7%, DM), and then cut at 5 (R05), 10 (R10), and 20 cm (R20) of the theoretical length of cut with no cut WCR (R60). Each forage was ensiled into 20 L mini bucket silo (5 kg) for 150 days in quadruplicates. The cutting lengths were not affected the chemical compositions of WCR silage (p > 0.05). The pH (p < 0.001) and concentration of ammonia-N (p = 0.022) in WCR silage were increased linearly with the increase of cutting length. The concentration of lactate had quadratic effect (p = 0.007), which was highest in R20 silage (p < 0.05). The concentration of acetate was increased linearly (p = 0.014), but the concentration of butyrate was decreased linearly (p = 0.033). The lactic acid bacteria count was decreased linearly (p = 0.017), and yeast count had quadratic effect (p = 0.009), which was the highest in R20 silage (p < 0.05). Aerobic stability had strong quadratic effect (p < 0.001), which was the highest in R20 silage (p < 0.05). In conclusion, R60 silage had highest pH by a linear increase of ammonia-N concentration and led to low aerobic stability. While R20 silage had the lowest pH by high lactate concentration and led to high aerobic stability.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.209-218
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• 2021

This study was carried out to investigate the effects of Bifidobacteria growth promoter BE0623 and a dietary fiber supplement, which included Bifidobacterium lactis BB12, Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium lactis. In fermented milk containing BE0623, the viable cell count of Bifidobacteria significantly increased by about 45 to 75 times compared to the control, and the titratable acidity increased, whereas the pH decreased. All fractions obtained by isolating BE0623 had Bifidobacteria growth effect. Acacia dietary fiber is a pale yellow powder. It has a viscosity of 60 to 100 cPs and a pH between 4.1 and 5.0. Its general components are less than 10% moisture, more than 90% dietary fiber, and less than 4% ash. The optimal addition ratio of Bifidobacteria growth promoting material was determined to be 0.05%. The general components of the manufactured fermented milk were carbohydrate 17.85%, protein 3.63%, fat 3.00%, and dietary fiber 2.95%. During storage of the fermented milk for 24 days, its titratable acidity, viscosity, and sugar content all met the criteria. In addition, the viable cell counts of Bifidobacteria and lactic acid bacteria in the fermented milk were 1.7 × 10⁸ CFU·mL^-1 and 1.5 × 10⁷ CFU·mL^-1, respectively, and Escherichia coli was negative. There was no significant difference between the control group and the treatment group in the sensory evaluation of sweet, sour, weight, and flavor, and the preference for the treatment group was excellent. The acceptability of the fermented milk of the treated group according to the storage period was excellent in terms of color, flavor, and appearance.

• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.106-114
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• 2008

One bacterium, which showed strong antagonistic activity against H. pylori KCCM 41756, was isolated from kimchi. The strain NO1 was designated as Lactobacillus plantarum NO1 based on Gram staining, biochemical properties, and 16S rRNA gene sequencing. The culture medium $(2{\sim}4{\mu}g/ml)$ of Lb. plantarum NO1 reduced $(40{\sim}60%)$ the urease activity of H. pylori KCCM 41756. Lb. plantarum NO1 inhibited the binding of H. pylori to human gastric cancer cell line, AGS cells, by more than 33%. Lb. plantarum NO1 exhibited high viability (maintained initial viable cell count of $10^9CFU/ml$) in 0.05 M sodium phosphate buffer (pH 3.0) for 2 h, in artificial gastricjuice for 2 h and in 0.3%, 0.5% oxgall for 24 h. Hemolysis phenomena did not observed when Lb. plantarum NO1 was incubated in the blood agar media. We concluded that Lb. plantarum NO1 can be a good candidate as a probiotic, harboring anti-H. pylori activity.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.285-291
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• 1996

The effect of various packaging methods on Kimchi quality was investigated in order to develop the packaging techniques for preventing commercial Kimchi Products from ination and explosion due to fermentative gas evolved during storage and distribution. Kimchi was packaged in different methods; atmospheric (AP), check-valved (CV), double (DP) and vacuum (VP) packaging. The quality of Kimchi during storage at $10^{\circ}C$ was evaluated ill terms of gas composition, free volume, pH, titratable acidity, color index, lactic acid bacteria and sensory properties. $O_2$ concentration decreased to about 1% at $6{\sim}8$ days of optimal ripening time in all packages except DP, in which it remained around 20%. $CO_2$ concentration reached $70{\sim}90%$ after $6{\sim}8$ days in AP, CV and DP, while it stayed around 10% in DP. The free volume in AP had typical sigmoidal curve similar to $CO_2$ concentration changes. It remained almost constant in CV and DP, but started to increase at the late stage of storage In VP. There was no significant influence of packaging methods on the other quality attributes such as pH, titratable acidity, color index (L.b/a), lactic acid bacteria count and sensory evaluation score. As results, it could be proposed to employ CV and DP method as the effective packaging techniques for preventing commercial Kimchi products from inflation.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.988-995
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• 2019

Objective: This study was conducted to estimate the temperature and microbial changes of corn silages during aerobic exposure. Methods: Kwangpyeongok (KW) and Pioneer 1543 (PI) corn hybrids were harvested at 29.7% of dry matter and chopped to 3 to 5 cm lengths. Homo (Lactobacillus plantarum; LP) or hetero (Lactobacillus buchneri; LB) fermentative inoculants at $1.2{\times}10^5$ colony forming unit/g of fresh forage was applied to the chopped corn forage which was then ensiled in quadruplicate with a $2{\times}2$ (hybrid${\times}$inoculant) treatment arrangement for 100 days. After the silo was opened, silage was sub-sampled for analysis of chemical compositions, in vitro digestibility, and fermentation indices. The fresh silage was continued to determine aerobic exposure qualities by recorded temperature and microbial changes. Results: The KW silages had higher (p<0.01) in vitro digestibilities of dry matter and neutral detergent fiber than those of PI silages. Silages applied with LB had higher (p<0.001) acetate concentration, but lower (p<0.01) lactate concentration and lactate to acetate ratio than those of LP silages. The interaction effect among hybrid and inoculant was detected in acetate production (p = 0.008), aerobic stability (p = 0.006), and lactic acid bacteria count (p = 0.048). The yeast was lower (p = 0.018) in LB silages than that in LP silages. During the aerobic exposure, PI silages showed higher (p<0.05) temperature and mold than KW silages, while LP silages had higher (p<0.05) lactic acid bacteria and yeast than LB silages. Conclusion: The results indicated that the changes of silage temperature during aerobic exposure seems mainly affected by mold growth, while applied LB only enhanced aerobic stability of PI silages.

• Food Science and Preservation
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• v.18 no.5
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• pp.786-794
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• 2011

To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at $10^{\circ}C$ for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the $10^{th}$ day of fermentation was ${\simeq}pH$ 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the $10^{th}$ day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.210-224
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• 2018

Warqe (Ensete ventricosum) has been traditionally fermented in an earthen pit to yield a carbohydrate-rich food product named kocho, for generations. A fermentation enhancer (gammaa) was added to this fermenting mass to enhance the fermentation process. The objectives of this study were to assess the physicochemical properties and microbiota of the kocho fermentation enhancer culture to reduce losses. Cross-sectional study design was implemented to collect 131 gammaa samples on the first day of fermentation. The samples were further classified into four groups according to the duration of fermentation (14, 21, 30, and 60 days) practised in various households traditionally. The results showed that the fermentation time significantly affected the physicochemical properties and microbial load of gammaa (p < 0.01). As the fermentation progressed from day 1 to 60, the pH decreased and the titratable acidity increased. The total coliform, Enterobacteriaceae, aerobicmesophilic bacteria (AMB), yeast, and mould counts were significantly reduced at the end of fermentation. In contrast, the number of lactic acid bacteria (LAB) increased significantly until day 30 of fermentation, because of the ability of the LAB to grow at low pH. Lactobacillus species from LAB isolates and Enter obacteriaceae from AMB isolates were the most abundant microorganisms in gammaa fermentation. However, the Enterobacteriaceae and Lactobacilli species count showed decreasing and increasing trends, respectively, as the fermentation progressed. These isolates must be investigated further to identify the species and strain, so as to develop gammaa at the commercial scale.

• Archives of Pharmacal Research
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• v.28 no.6
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• pp.660-666
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• 2005

The intestinal microbiota are important to the host with regard to resistance they impart against bacterial infections and their involvement in mediating metabolic functions. Lactic acid producing bacteria such as Lactobacillus play an important physiological role in these matters. The aim of the present study was to isolate Lactobacillus sp. that inhibits enteric pathogens. Initially, 17 isolates from healthy Koreans were collected on Lactobacillus selective medium. Resistance of the isolates to antibiotics including rifampicin, streptomycin, clindamycin and vancomycin was measured. One of the isolate was identified as Lactobacillus ruminus on the basis of bacterial cell morphology, cultural characteristic and biochemical characteristics, 16S rRNA sequence analysis and PCR-RAPD. Antimicrobial activity of the bacterium against Vancomycin Intermediate Resistant Staphylococcus aureus (VISA) and Vancomycin-Resistant Enterococci (VRE) was measured. About $10^4$ cells of VISA or VRE were mixed with 1, 5, and 9 mL of L. ruminus SPM 0211 and the final volume was adjusted to 10 mL with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 h, serially diluted and then plated on BHI agar plates. As numbers of L. ruminus SPM 0211 were increased, viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of SPM 0211 was observed after 9 h incubation in any mixture, almost completely inhibiting the growth of these two bacteria. The results suggest that the freshly isolated L. ruminus SPM 0211 may be used as a pro-biotic microbe that prevents the colonization of enteric pathogens and can thereby promote good gastrointestinal health.