• Journal of Food Hygiene and Safety
• /
• v.31 no.1
• /
• pp.42-50
• /
• 2016

The effects of freezing and thawing conditions on microbiological quality and microstructure change of inoculated (Listeria monocytogenes and Campylobacter jejuni) and non-inoculated chicken breasts were investigated. Chicken breasts were frozen with air blast freezing (-20, -70, and $-150^{\circ}C$), ethanol ($-70^{\circ}C$) and liquid nitrogen ($-196^{\circ}C$) immersion freezing. There were no significant differences on the populations of L. monocytogenes inoculated with chicken breasts under different freezing conditions. However, air blast freezing ($-20^{\circ}C$) resulted in significant reductions for total aerobic bacteria and C. jejuni compared to the control and other freezing treatments. The frozen samples were thawed with (hot or cold) air blast, water immersion, and high pressure thawing at $4^{\circ}C$ and $25^{\circ}C$. the populations of total aerobic bacteria, and yeast and mold in the frozen chicken breast increased by 5.78 and 4.05 log CFU/g after water immersion thawing ($25^{\circ}C$) treatment. After five freeze-thaw cycles, the populations of total aerobic bacteria, yeast and mold, and C. jejuni were reduced by 0.29~1.40 log cycles, while there were no significant differences (P > 0.05) in the populations of L. monocytogenes depending on the freeze-thaw cycles. In addition, the histological examination of chicken breasts showed an increase in spacing between the muscle fiber and torn muscle fiber bundles as the number of freeze-thaw cycles increased. These results indicate that freezing and thawing processes could affect in the levels of microbial contamination and the histological change of chicken breasts.

• Korean Journal of Poultry Science
• /
• v.31 no.1
• /
• pp.25-31
• /
• 2004

The effect of drinking rhus tree-extract on performance of broiler was performed to investigate development of natural antibiotic in process of broilers production. A total of 320 broiler chicks at 1 day of age were fed the commercial diet and water, drinking water containing 0 ppm(control), 500 ppm (T1), 1,000 ppm (T2) and 2,000 ppm (T3) of rhus tree-extract fur seven weeks. The body weight gain and fred conversion ratio were not different by drinking rhus tree-extract until 35 days of age, but body weight gain and feed conversion ratio were tend to improve by drinking rhus tree-extract over 35 days of age, the improvement was higher in both T$_1$, and T$_3$ than control group(p＜0.05) when 35 to 42 days of age. There was a decrease in the microflora population of both E. coli. end Salmonella in the cecum contents and feaces in broilers by drinking rhus tree-extract. The digestibility of dry matter, crude fat, and crude ash of feed were tend to increased in broiler drinking rhus tree-extract. Digestibility of crude protein of feed in broiler three treated groups was significantly improved (p＜0.15) as compared with those in control group. These results indicated that the drinking rhus tree-extract were effective in the body weight gain, feed conversion ratio, decreasing of microflora population of both E. coli and Salmonella in the cecum contents and feaces, and it had also effective the digestibility of nutrients in broilers.

• Natural Product Sciences
• /
• v.6 no.4
• /
• pp.161-164
• /
• 2000

Herbal medicinal interaction on the purgative action of Chungpesagan-tang, which is one of the traditional Korean medical prescriptions that has been most frequently used for stroke was investigated. Chungpesagan-tang had more potent purgative activity than Rhei Rhizoma alone. When each Chungpesagan-tang composing herbal medicine with Rhei Rhizoma was extracted with water, water extract of Raphani Semen with Rhei Rhizoma had the most potent purgative activity. However, Raphani Semen had not purgative activity. When Rhei Rhizoma with Raphani Semen was extracted, sennoside A content in the water extract was increased. The transformation of sennoside A of Rhei Rhizoma to rheinanthrone by human intestinal microflora was weakly induced by Raphani Semen. These results suggest that the purgative action of Chungpesagan-tang could be controlled by the addition and subtraction of Chungpesagan-tang-composing herbal medicines.

• Proceedings of the SCSK Conference
• /
• 2003.09a
• /
• pp.85-96
• /
• 2003

Normal human skin, constantly challenged by environmental micro-organisms, has an innate ability to fight invading microbes through antimicrobial peptides. These peptides, described in both plant and animal kingdoms are able to inactivate a broad spectrum of micro-organisms. Mammalian defensins constitute one of the most common antimicrobial peptide family. Among the three human beta-defensins hBD1, hBD2 and hBD3 produced in epithelia, only hBD2 and hBD3 are inducible and additionally have been described as expressed by differentiated keratinocytes at site of inflammation and infection. The aims of these studies were to define a cell culture model in which the basal production of hBD could be detected and up-regulated in order to enhance skin auto-protection against micro-organisms. A specific Polymerase Chain Reaction method have been developed for hBD2 and hBD3 mRNA detection in non-differentiated monolayer keratinocytes cell culture. We have been able to demonstrate that in vitro, hBD2 and hBD3 expression in normal human keratinocytes could be detected and enhanced by TNF-alpha and IFN-gamma, in hypercalcic culture conditions. This research opened the possibility of the development of cosmetic active compounds, able to induce the expression of skin natural antibiotic peptides responsible about microflora ecology of the skin.

• Toxicological Research
• /
• v.26 no.4
• /
• pp.301-313
• /
• 2010

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-$17\beta$, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA). Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

• Archives of Pharmacal Research
• /
• v.21 no.1
• /
• pp.17-23
• /
• 1998

Flavonoid glycosides were metabolized to phenolic acids via aglycones by human intestinal microflora producing ${\alpha}$-rhamnosidase, exo-${\beta}$-glucosidase, endo- ${\beta}$-glucosidase and/or ${\beta}$-glucuronidase. Rutin, hesperidin, naringin and poncirin were transformed to their aglycones by the bacteria producing ${\alpha}$-rhamnosidase and ${\beta}$-glucosidase or endo- ${\beta}$-glucosidase, and baicatin, puerarin and daidzin were transformed to their aglycones by the bacteria producing ${\beta}$glucuronidase, C-glycosidase and ${\beta}$-glycosidase, respectively. Anti-platelet activity and cytotoxicity of the metabolites of flavonoid glycosides by human intestinal bacteria were more effective than those of the parental compounds. 3,4-Dihydroxyphenylacetic acid and 4-hydroxyl-phenylacetic acid were more effective than rutin and quercetin on anti-platelet aggregation activity. 2,4,6-Trihydroxybenzaidehyde, quercetin and ponciretin were more effective than rutin and ponciretin on the cytotoxicity for tumor cell lines. We insist that these flavonoid glycosides should be natural prodrugs.

• Korean Journal of Poultry Science
• /
• v.18 no.2
• /
• pp.97-119
• /
• 1991

Effect of Streptococcus faecium(SF) and an antibiotic, Colistin(Col), supplemented to diets singly or in combination, on the performances and changes of intestinal population of microflora of broiler chicks studied. A total of 252, day-old chicks(Arbor Acre) of mixed sex(M：F＝1：1) were alloted into six groups. A diet with no Col and SF was referred as a control diet. The basal diets were added with two levels of SF, 0.04 and 0.08%, singly or in combination with Col 10ppm Another diet was prepared by adding only Col 10 ppm. Numbers of the microorganism in diets added with SF 0.04% and 0.08% were 7$\times$10$^{4}$ and 1.4$\times$10$^{5}$ /g diet respectively The diets consisting of corn and soybean meal as major ingredients were fed for a period of seven weeks . During the feeding trial, fresh excreta were sampled at the end of every week in a sterilized condition to count microbial changes from each dietary group. Microbial changes of large intestine were also measured from nine birds sacrificed at the end of the 4th and 7th weeks each time per dietary group. Excreta from all the groups were also collected quantitatively at the end of 3rd and 6th weeks to measure digestibility of the diets, At the end of 7th week, nine birds from each group were also sacrificed to measure weight changes of gastrointestinal tracts . Average body weight gains of broilers fed the diets added with SF 0.08% (2.37kg) or SF 0. 08%+col 10ppm(2.34kg) were significantly larger than that of the control(2.18kg). The weight gains of the other groups were not statistically different from that of the control Feed/gain ratios of the supplemental groups were better than that of control (P＜0.05) except that of birds fed the diet added only with SF 0.04%. Digestibilities of nutrients such as dry matter, crude protein, crude fat and total carbohydrates were not altered by the consumption of the diets added with SF and/or Col throughout the whole feeding period. As expected, the numbers of Streptococci in the excreta from birds fed diets added with SF increased significantly with a statistical difference between groups with SF 0.04% and SF 0.08% most of the time. However. addition of Colistin to the diets supplemented with SF did not give any effects on the number of the microorganism. Numbers of coliforms in the excreta were apparently reduced by feeding the diets added with SF and/or Col(P＜0.05). There were, however, no additive effects observed between the two feed additives in this regard when supplementing Col to the SF diets. Distributions of intestinal microflora exhibited exactly the same pattern as those of the excreta. Length of small intestine of the birds fed diets added with SF 0.08% with or without Col 10 ppm became significantly longer with a range of about 10% than those of the birds fed diets without SF. However, the empty weight of the small inestine of the former group was lighter than that of control These changes resulted in a significant reduction in weight/unit length of the intestine of the birds fed diets supplemented with Col and SF singly or in combination. In overall conclusion, diet added with SF 0.08% appeared most effective in improving broiler performances. Colistin added at a level of 10ppm was not beneficial at all in itself or in combination with SF in terms of broiler performances or changes of intestinal microflora population. The efficacy of SF and Col could be attributed to the changes of wall thickness of the small intestine.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.838-848
• /
• 2012

Orally administered herbal glycosides are metabolized to their hydrophobic compounds by intestinal microflora in the intestine of animals and human, not liver enzymes, and absorbed from the intestine to the blood. Of these metabolites, some, such as quercetin and kaempherol, are mutagenic. The fecal bacterial enzyme fraction (fecalase) of human or animals has been used for measuring the mutagenicity of dietary glycosides. However, the fecalase activity between individuals is significantly different and its preparation is laborious and odious. Therefore, we developed a fecal microbial enzyme mix (FM) usable in the Ames test to remediate the fluctuated reaction system activating natural glycosides to mutagens. We selected, cultured, and mixed 4 bacteria highly producing glycosidase activities based on a cell-free extract of feces (fecalase) from 100 healthy Korean volunteers. When the mutagenicities of rutin and methanol extract of the flos of Sophora japonica L. (SFME), of which the major constituent is rutin, towards Salmonella typhimurium strains TA 98, 100, 102, 1,535, and 1,537 were tested using FM and/or S9 mix, these agents were potently mutagenic. These mutagenicities using FM were not significantly different compared with those using Korean fecalase. SFME and rutin were potently mutagenic in the test when these were treated with fecalase or FM in the presence of S9 mix, followed by those treated with S9 mix alone and those with fecalase or FM. Freeze-dried FM was more stable in storage than fecalase. Based on these findings, FM could be usable instead of human fecalase in the Ames test.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.4
• /
• pp.641-645
• /
• 2001

To utilize the by-products from whelk processing, whelk internal organ jeotgal was manufactured by adding pineapple and kiwifruit juices containing bromelain and actinidin, respectively. The protease activities of pineapple and kiwifruit juices were 52 and 248 unit/mL, respectively. 1 kg ground whelk internal organ was immersed to 12.5% salt concentration and then the 20, 50, or 100 mL of fruit juice were added in it. the quality of products fermented for up to 70 day at 1$0^{\circ}C$ was observed. Jeotgal wit pineapple juice showed lower pH and higher amino nitrogen content than with kiwifruit juice on 70 day of fermentation. the total nitrogen contents was the highest on 30 day of fermentation and stable thereafter. Although total numbers of microorganism were increased as fermentation progressed, there were no correlations among the juices or its adding amounts. It was thought that interactions between kinds of natural microflora and the proteases from fruit juices, and other constituents in jeotgal affected total nitrogen content of jeotgal and the growth rate of natural microorganisms. Of the all jeotgals in this study, no coliform was found It is suggested that the preparation of jeotgal with pineapple or kiwifruit juice is effective aspect of safety and quality.

• Korean Journal of Food Science and Technology
• /
• v.37 no.5
• /
• pp.844-849
• /
• 2005

Bacteriocidal effect of calcium oxide (CaO, scallop shell powder) on reduction of microorganism in sesame leaf was evaluated through comparison with chemical sanitizers such as chlorine, ethanol, and hydrogen peroxide. CaO showed 0.55-1.49, 0.85-2.56, 0.16-1.08, 0.30-1.14, and $0.19-1.07\;log_{10}$ CFU/g reductions of total aerobic bacteria, total coliforms, Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium respectively, indicating possible use of CaO as effective natural sanitizer.