• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.995-1000
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• 1996

The present study was attempted to preprare calcium-fortified soymilk using proteases to improve calcium intolerance of soymilk protein and to evaluate its nutritional properties. The protease from Bacillus polymyxa was chosen as an enzyme source because it produced the least bitter taste and calcium-aggregation of soymilk among various enzymes. The optimum treatment time was 10 minutes at $50^{\circ}C$ for the best result. In vitro protein digestibility of calcium-fortified soymilks was comparable with that of control soymilk. Calcium in the digested soymilks was mostly in the ionic form and the amount of ionic calcium increased in accordance with the amount of fortified calcium in soymilk. This suggests that fortified calcium in the soymilk is bioavailable.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.1064-1079
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• 2018

In this study, the antimicrobial activity of a bacteriocin produced by Enterococcus faecalis KT11, isolated from traditional Kargı Tulum cheese, was determined, and bacteriocin KT11 was partially characterized. The results showed that bacteriocin KT11 was antagonistically effective against various Gram-positive and Gram-negative test bacteria, including vancomycin- and/or methicillin-resistant bacteria. The activity of bacteriocin KT11 was completely abolished after treatment with proteolytic enzymes (proteinase K, ${\alpha}$-chymotrypsin, protease and trypsin), which demonstrates the proteinaceous nature of this bacteriocin. Additionally, bacteriocin KT11 remained stable at pH values ranging from 2 to 11 and after autoclaving at $121^{\circ}C$ for 30 min. In addition, the activity of bacteriocin KT11 was stable after treatment with several surfactants (EDTA, SDS, Triton X-100, Tween 80 and urea) and organic solvents (chloroform, propanol, methanol, ethyl alcohol, acetone, hexane and ethyl ether). Cell-free supernatant of E. faecalis KT11 was subjected to ammonium sulfate precipitation and then desalted by using a 3.5-kDa cut-off dialysis membrane. The bacteriocin activity was determined to be 711 AU/mL in the dialysate. After tricine-SDS-PAGE analysis, one peptide band, which had a molecular weight of ~3.5 kDa, exhibited antimicrobial activity. Because the bacteriocin KT11, isolated from E. faecalis KT11, exhibits a broad antimicrobial spectrum, heat stability and stability over a wide pH range, this bacteriocin can be used as a potential bio-preservative in foods. Additionally, bacteriocin KT11 alone or in combination with conventional antibiotics may provide a therapeutic option for the treatment of multidrug-resistant clinical pathogens after further in vivo studies.

• Journal of Korean Neurosurgical Society
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• v.42 no.5
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• pp.392-399
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• 2007

Objective : Arsenic trioxide ($As_2O_3$) has been used as an anticancer agent in traditional Chinese medicine for thousand years and berberine is an isoquinoline alkaloid present that has indicated significant antimicrobial activity. We have examined the combined anticancer effects of $As_2O_3$ and berberine against the human neuroblastoma (HNB) SH-SY5Y cells in vitro, and to elucidate underlying molecular mechanism. Methods : HNB SH-SY5Y cells were treated with $2\;{\mu}M\;As_2O_3$ and $75\;{\mu}g/ml$ berberine, and their survival, cell death mechanism as well as synergistic cytotoxic effects were estimated by using MTT assay, DAPI staining, agarose gel electrophoresis, flow cytometric analysis, and western blot analysis. Results : The combined treatment of two drugs also markedly decreased cell viability. The cytotoxic effects of two drugs were revealed as apoptosis characterized by chromatin condensation, DNA fragmentation, and the loss of mitochondrial membrane potential. The apoptotic cytotoxicity was accompanied by activation of caspase-3 protease as well as decreased the expression of Bcl-2, Bid, and Bcl-x/L. In addition, the cells treated with combination of two drugs also showed significantly increased intracellular reactive oxygen species levels and lipid peroxidation compared to cells $As_2O_3$or berberine only. Conclusion : Combined treatment of $As_2O_3$ with berberine induced activation of apoptotic signaling pathways in HNB SH-SY5Y cells. These results suggest that the possibility of the combined treatment of two chemotherapeutic agents with low concentration improving cytotoxic effect for cancer cells with minimal side effects.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.114-117
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• 2002

During the screening of inhibitors of caspase-3 induction in U937 human monocytic leukemia cells from natural sources, Forsythiae fructus, which showed a high level of inhibition, was selected. And then, the compound was purified from the methanol extract using silica gel column chromatography and HPLC. The inhibitor was identified as rengyolone, by spectroscophic methods of ESI-MS, $^1H-NMR$, $^{13}C-NMR$, DEPT, and HMBC. Rengyolone showed inhibitory activity of caspase-3 induction, a major protease of apoptosis cascade, with an $IC_{50}$ value of $6.25\;{\mu}g/mL$ after 7 h of treatment in U937 cells. It also showed inhibitory activity of caspace-1 induction, with an $IC_{50}$ value of $7.50\;{\mu}g/mL$ after 40 h of treatment in D10S cells. In addition, it showed protective effect against cell death with an $IC_{50}$ value of $11\;{\mu}g/mL$ on U937 cells induced by etoposide after 24 h of treatment, but did not show any cytotoxicity at the same condition without etoposide, a caspase 3 inducing agent.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.151-157
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• 2014

This study investigated the effects of three proteases (trypsin, pepsin and chymotrypsin) on the hydrolysis efficiency of porcine placenta and the molecular weight (Mw) distributions of the placental hydrolysates. Because placenta was made up of insoluble collagen, the placenta was gelatinized by applying thermal treatment at $90^{\circ}C$ for 1 h and used as the sample. The placental hydrolyzing activities of the enzymes at varying concentrations and incubation times were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and gel permeation chromatography (GPC). Based on the SDS-PAGE, the best placental hydrolysis efficiency was observed in trypsin treatments where all peptide bands disappeared after 1 h of incubation as compared to 6 h of chymotrypsin. Pepsin hardly hydrolyzed the placenta as compared to the other two enzymes. The Mw distribution revealed that the trypsin produced placental peptides with Mw of 106 and 500 Da. Peptides produced by chymotrypsin exhibited broad ranges of Mw distribution (1-20 kDa), while the pepsin treatment showed Mw greater than 7 kDa. For comparisons of pre-treatments, the subcritical water processing (37.5 MPa and $200^{\circ}C$) of raw placenta improved the efficiency of tryptic digestions to a greater level than that of a preheating treatment ($90^{\circ}C$ for 1 h). Consequently, subcritical water processing followed by enzymatic digestions has the potential of an advanced collagen hydrolysis technique.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.265-272
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• 2006

Dental plaque, a biofilm consisting of more than 500 different bacterial species, is an etiological agent of human periodontal disease, It is therefore important to characterize interactions among periodontopathic microorganisms in order to understand the microbial pathogenesis of periodontal disease. Previous data have suggested a synergistic effect of tow major periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia in the periodontal lesion. In the present study, to better understand interaction between P. gingivalis and T. forsythia, the coaggregation activity between these bacteria was characterized. The coaggregation activity was observed by a direct visual assay by mixing equal amount (1 ${\times}$ $10^9$)of T. forsythia and P. gingivaJis cells. It was found that the first aggregates began to appear after 5-10 min, and that the large aggregates completely settled within 1 h. Electron and epifluorescence microscopic studies confirmed cell-cell contact between two bacteria. The heat treatment of P. gingivalis completely blocked the activity, suggesting an involvement of a heat-labile component of P. gingivalis in the interaction. On the other hand, heat treatment of T. forsythia significantly increased the coaggregation activity; the aggregates began to appear immediately. The coaggregation activity was inhibited by addition of protease, however carbohydrates did not inhibit the activity, suggesting that coaggregation is a protein-protein interaction. The results of this study suggest that coaggregation between P. gingivalis and T. forsythia is a result of cell-cell physical contact, and that coaggregation is mediated by a heat-labile component of P. gingivalis and T. forsythia component that can be activated on heat treatment.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1125-1130
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• 1997

The effects of enzyme combination, pH, acid washing and enzyme treatment sequence were investigated in the hydrolysis of soy protein. Comparing Alcalase vs. Neutrase/Alcalase, it appeared that Neutrase/Alcalase was more efficient than Alcalase alone, as the highest degree of hydrolysis (DH) was seen in Neutrase/Alcalase. A surprisingly high DH (more than 60%) was observed with Flavourzyme in the second hydrolysis. The separation of insolubles from the first hydrolysis had little effect on the second hydrolysis. When the washing water from the first hydrolysis was reused in the next hydrolysis, the DH and protein recovery were increased. The addition of calcium ion showed not so much positive effects by the stabilization of Neutrase on the Protein hydrolysis. The use of carbohydrase and repeated acid washing gave positive effects on DH. The simultaneous treatment using endoprotease and exoprotease with pH adjustment improved DH significantly.

• Animal Bioscience
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• v.34 no.7
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• pp.1157-1168
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• 2021

Objective: The aim of this study was to investigate the effects of different amounts of wheat bran (WB) inclusion and postbiotics form by Saccharomyces cerevisiae and phytase co-fermented wheat bran (FWB) on the growth performance and health status of broilers. Methods: Study randomly allocated a total of 300 male broilers to a control and 4 treatment groups (5% WB, 5% FWB, 10% WB, and 10% FWB inclusion, respectively) with each pen having 20 broilers and 3 pens per treatment. Results: The WB does not contain enzymes, but there are 152.8, 549.2, 289.5, and 147.1 U/g dry matter xylanase, protease, cellulase and β-glucanase in FWB, respectively. Furthermore, FWB can decrease nitric oxide release of lipopolysaccharide stimulated chicken peripheral blood mononuclear cells by about two times. Results show that 10% FWB inclusion had significantly the highest weight gain (WG) at 1 to 21 d; 5% FWB had the lowest feed conversion rate at 22 to 35 d; 10% WB and 10% FWB inclusion have the highest villus height and Lactobacillus spp. number in caecum; and both 5% and 10% FWB can increase ash content in femurs. Compared to control group, all treatments increase mucin 2, and tight junction (TJ), such as occludin, claudin-1, zonula occludens-1, and mRNA expression in ileum by at least 5 folds. In chicken peripheral blood mononuclear cells, nicotinamide adenine dinucleotide phosphate-oxidase-1 mRNA expression decreases from 2 to 5 times, and glutamate-cysteine ligase catalytic subunit mRNA expression also increases in all treatment groups compared to control group. The mRNA expression of pro-inflammatory cytokines, including interleukin-6 (IL-6), nuclear factor-κB, and IL-1β, decreases in 5% and 10% FWB groups compared to control group. Conclusion: To summarize, both WB and FWB inclusion in broilers diets increase TJ mRNA expression and anti-oxidation and anti-inflammation, but up to 10% FWB groups have better WG in different stages of broiler development.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.267-274
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• 2014

High pressure processing (HPP) is a non-thermal method used to prevent bacterial growth in the food industry. Currently, pasteurization is the most common method in use for most milk processing, but this has the disadvantage that it leads to changes in the milk's nutritional and chemical properties. Therefore, the effects of HPP treatment on the microbiological and chemical properties of milk were investigated in this study. With the treatment of HPP at 600 MPa and $15^{\circ}C$ for 3 min, the quantity of microorganisms and lactic acid bacteria were reduced to the level of 2-3 log CFU/ml, and coliforms were not detected during a storage period of 15 d at $4^{\circ}C$. An analysis of milk proteins, such as ${\alpha}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin by on-chip electorophoresis revealed that the electrophoretic pattern of the proteins from HPP-treated milk was different from that of conventionally treated commercial milk. While the quantities of vitamins and minerals in HPP-treated milk were seen to be comparable to amounts found in raw milk, the enzyme activity of lipase, protease and alkaline phosphatase after HPP treatment was reduced. These results suggest that HPP treatment is a viable method for the control of undesirable microorganisms in milk, allowing for minimal nutritional and chemical changes in the milk during the process.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.74-80
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• 1994

As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protein hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae$(5.05{\sim}11.47)$ were much higher than those of the tryptic or chymotryptic WPH$(15.67{\sim}20.20)$. And the pretreatments of heat$(75^{\circ}C)$, 20 min and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than 10kDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were $4,252{\sim}9,132$ dalton and $38{\sim}83$ amino acids, respectively. And there was no bitter taste in all of the WPH. Results of SDS-PAGE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovalent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to $10^{-1.7}-10^{-4.9}$ times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigenicicy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.