• 한국식품영양과학회지
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• 제30권5호
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• pp.888-893
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• 2001

Soy sauce has a long history used as a food ingredient. However, hydrolyzed vegetable protein, mono-sodium glutamate, starch syrup, and fructose are added to soy sauce during fermentation for the taste and flavor of product. But consumers have been reluctant to the taste of these artificial additives. In this experiment, anchovy sauce was used to prepare soy sauce to enhance the quality and brine was used as a control. To evaluate the quality of soy sauce added with anchovy, total nitrogen (TN) and soluble nitrogen contents, total soild contents, total sugar reducing sugar. lactic acid content and protease activity were monitored during fer-mentation. Total microbial numbers and lactic acid bacteria were not significantly changed among the cases. Aerobic and anaerobic microorganisms. and lactic acid bacteria were not significantly changed among the cases we studied, For the total sensory test, it was also estimated that the cases using anchovy sauce were superior to the control. From the results mentioned above, we could obtain shorter fermenation period as well as the quality improvement in the case of using anchovy sauce instead of salty water in the fermented soy sauce production.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1228-1236
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• 1997

Lactobacillus strains were isolated from volunteer's feces, including from newly-born infants and adults in their 20's, by using differential MRS-BPB plates. Total 56 presumptive Lactobacillus strains were isolated and the bacteriocin productions by the isolates were examined by agar diffusion method. Six bacteriocin-producing strains were confirmed. Among them, two isolates, HU-1 and H22-3, showed the most outstanding antimicrobial activities, which were not affected by pH adjustments or catalase treatments of culture. HU-1 was originated from a two-years old boy and H22-3 was originated from a newly-born infant. HU-1 and H22-3 had the same morphology(short rod) when examined by scanning electron microscope, and the same biochemical traits including growth temperature range, salt tolerance and sugar-fermenting abilities. But the growth-inhibition spectrum and plasmid profiles of HU-1 and H22-3 were different. Both strains inhibited the growth of various Gram (+) microorganisms including Listeria monocytogenes. Micrococcus luteus, and Staphylococcus aureus in addition to many species of lactic acid bacteria, indicating the production of broad-spectrum bacteriocins. Bacteriocins produced by HU-1 and H22-3 were stable up to 90℃, 15 min heat treatments. Their activities were not affected by pepsin or trypsin treatments but destroyed by proteinaseK or pronase treatments.

• Journal of Dairy Science and Biotechnology
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• 제37권2호
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• pp.83-93
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• 2019

Food spoilage by fungi is responsible for considerable food waste and economical losses. Among the food products, fermented dairy products are susceptible to deterioration due to the growth of fungi, which are resistant to low pH and can proliferate at low storage temperatures. For controlling fungal growth in dairy products, potassium sorbate and natamycin are the main preservatives used, and natamycin is approved by most countries for use in cheese surface treatment. However, a strong societal demand for less processed and preservative-free food has emerged. In the dairy products, lactic acid bacteria (LAB) are naturally present or used as cultures and play a key role in the fermentation process. Fermentation is a natural preservation technique that improves food safety, nutritional value, and specific organoleptic features. Production of organic acids is one of the main features of the LAB used for outcompeting organisms that cause spoilage, although other mechanisms such as antifungal peptides obtained from the cleavage of food proteins and competition for nutrients also play a role. More studies for better understanding these mechanisms are required to increase antifungal LAB available in the market.

• Animal Bioscience
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• 제34권4호
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• pp.533-538
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• 2021

Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.64-71
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• 2022

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

• 한국축산식품학회지
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• 제42권6호
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• pp.1009-1019
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• 2022

In recent years, biocontrol of foodborne pathogens has become a concern in the food industry, owing to safety issues. Listeria monocytogenes is one of the foodborne pathogens that causes listeriosis. The major concern in the control of L. monocytogenes is its viability as it can survive in a wide range of environments. The purpose of this study was to isolate lactic acid bacteria with antimicrobial activity, evaluate their applicability as a cheese starter, and evaluate their inhibitory effects on L. monocytogenes. Lactococcus lactis strain with antibacterial activity was isolated from raw milk. The isolated strain was a low acidifier, making it a suitable candidate as an adjunct starter culture. The commercial starter culture TCC-3 was used as a primary starter in this study. Fresh cheese was produced using TCC-3 and L. lactis CAU2013 at a laboratory scale. Growth of L. monocytogenes (5 Log CFU/g) in the cheese inoculated with it was monitored during the storage at 4℃ and 10℃ for 5 days. The count of L. monocytogenes was 1 Log unit lower in the cheese produced using the lactic acid bacteria strain compared to that in the cheese produced using the commercial starter. The use of bacteriocin-producing lactic acid bacteria as a starter culture efficiently inhibited the growth of L. monocytogenes. Therefore, L. lactis can be used as a protective adjunct starter culture for cheese production and can improve the safety of the product leading to an increase in its shelf-life.

• 한국미생물·생명공학회지
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• 제12권4호
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• pp.285-291
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• 1984

액상발효유 제조시에 유산균 starter의 단백질 분해능이 산생성과 제품의 단백질 안정성에 미치는 영향을 조사하였다. L. bulgarious CH 2, L. helviticus IAM 1042, L. jugurti 3048은 우유에 배양할 때에 비교적 높은 단백질 분해능을 나타내었으나 L. casei YIT 9018은 단백질 분해능이 아주 약했다. 또 단백질 분해능이 높은 균들은 낮은 균들보다 우유에서의 증식과 산생성 속도가 빨랐다. 유단백질의 분해가 가장 심하게 이루어지는 시기는 균의 대수증식기이었고, 배양개시로부터 24∼48시간 이후에서는 유단백질의 분해가 거의 더 진행되지 않았다. L. bulgaricus CH 2, L. helviticus IAM 1042, L. jugurti 3048, L. acidophilus L 54, L. casei 3012로 제조된 발효유들은 모두 유단백질 분해가 비교적 심하게 일어났고, pH 3.5에서의 유단백질 용해도가 낮았고, 제품의 저장시에 유단백질 침전이 심하게 생성되었다. 그러나 artificial acidification이나 L. casei YIT 9018에 의하여 제조된 제품들은 유단백질의 분해가 거의 없었고, pH 3.5 에서의 단백질 용해도도 높았고, 저장시에 침전도 전혀 발생되지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1580-1590
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• 2019

Objective: The aims of this study were to select one strain of Lactobacillus plantarum (L. plantarum) for a potential indigenous safe starter culture with low level antibiotic resistant and low biogenic amine production and evaluate its effect on biogenic amines reduction in Moo som. Methods: Three strains of indigenous L. plantarum starter culture (KL101, KL102, and KL103) were selected based on their safety including antibiotic resistance and decarboxylase activity, and fermentation property as compared with a commercial starter culture (L. plantarum TISIR543). Subsequently, the effect of the selected indigenous safe starter culture on biogenic amines formation during Moo som fermentation was studied. Results: KL102 and TISIR 543 were susceptible to penicillin G, tetracycline, chloramphenicol, erythromycin, gentamycin, streptomycin, vancomycin, ciprofloxacin and trimethoprim (MIC90 ranging from 0.25 to $4{\mu}g/mL$). All strains were negative amino acid-decarboxylase for lysis of biogenic amines in screening medium. For fermentation in Moo som broth, a relatively high maximum growth rate of KL102 and TISIR543 resulted in a generation time than in the other strains (p<0.05). These strain counts were constant during the end of fermentation. Similarly, KL102 or TISIR543 addition supported increases of lactic acid bacterial count and total acidity in Moo som fermentation. For biogenic amine reduction, tyramine, putrescine, histamine and spermine contents in Moo som decreased significantly by the addition KL102 during 1 d of fermentation (p<0.05). In final product, histamine, spermine and tryptamine contents in Moo som inoculated with KL102 were lower amount those with TISIR543 (p<0.05). Conclusion: KL102 was a suitable starter culture to reduce the biogenic amine formation in Moo som.

• 한국식품영양학회지
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• 제7권2호
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• pp.151-158
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• 1994

This study was carried out to clear up the cause of low-acid producing phenomenon occurred In non-fat dry milk during liquid-yoghurt fermentation by Lactobacillus case, and to present its improving methods. All samples of non-fat dry milks which were low in TCA-soluble peptides showed low-acid production, but those high in TCA-soluble peptides showed high-acid production. The addition of trypsin-hydrolysate of Na-caseinate to non-fat dry milk showed some improving effect on acid production but that of papain-hydrolysate did not show any improving effect and that of bacterical neutral protease-hydrolysate showed some inhibitory effect. The improving effects on growth and acid production of lactic acid bacteria were more prominent when the trypsin-hydrolysate of Na-caseinate was added. to such fermenting system in which the levels of TCA-soluble peptides and the proteolytic ability of starter bacteria were abnormally low. The liquid-yoghurt made with non-hydrolysed Na-caseinate and defective non-fat dry milk showed precipitate occurrence but that with trypsin-hydrolysate of Na-caseinate and defective non-fat dry milk did not make any precipitate during storage as with normal non-fat dry milk.

• 한국식품과학회지
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• 제23권6호
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• pp.745-749
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• 1991

대두단백젖산발효물과 쌀젖산발효물의 특성을 비교하였다. 쌀젖산발효물은 색택, 향미가 우수하였고 대두단백 젖산발효물은 영양과 물성이 우수하였다. 쌀젖산발효물과 대두단백 젖산발효물 각각의 우수한 특성을 이용하기 위하여 이들을 혼합하였고 이혼합물을 라이소거트라 명명하였다. 라이소거트는 대두젖산발효물 보다 향, 맛, 색택, 종합적기호도가 월등하였으며, 영영 및 유변학적 특성면에서 쌀젖산발효물 보다 우수하였다. 라이소거트의 적정혼합비율은 쌀젖산발효물: 대두단백젖산발효물 75:25 이었다.