• Food Science and Preservation
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• v.16 no.5
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• pp.636-643
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• 2009

Inactivation by UV-C irradiation of Escherichia coli O157:H7 and Listeria monocytogenes inoculated onto washed carrots was examined. Carrot samples were inoculated with 6-7 log CFU/mL of E. coli O157:H7 or L. monocytogenes, treated with doses of 0, 1, 3, 5, or $10\;kJ/m^2$ UV-C, and stored at $4{\pm}1^{\circ}C$ for 8 d. The populations of E. coli O157:H7 and L. monocytogenes significantly decreased with increasing irradiation dose (p<0.05). In particular, E. coli O157:H7 and L. monocytogenes populations fell significantly by 2.35 and 2.38 log CFU/g at $10\;kJ/m^2$, respectively, compared to control values. UV-C irradiation inhibited color changes and decreased the whiteness index in carrot during storage, compared to controls. Sensory evaluation results showed that UV-C-treated carrots had better sensory characteristics than did the control. Therefore, the results suggest that UV-C irradiation could be useful to improve the microbial safety and sensory qualities of fresh-cut carrots during storage.

• Food Science and Preservation
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• v.16 no.6
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• pp.971-976
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• 2009

The consumption of raw sprouts has increased in popularity worldwide because the food is natural and healthy. However, in Korea, nothing is known on the safety standards of sprout producers or changes in the microbial populations of sprouts during sprouting. We evaluated the microbial safety and quality of sprouts during each step in the sprouting process. Bacteriological analysis showed that seeds had a Total Plate Count (TPC) ranging from 3.04 - 5.21 log CFU/g and coliform counts ranging from 1.80 - 3.86 log CFU/g. TPC and coliform counts increased rapidly during the sprouting process to attain values of 6.99 - 8.26 and 3.70 - 7.15 log CFU/g, respectively, regardless of decontamination of seeds with commercial sanitizer. TPC and coliform counts were on high level after sprouts were washed. Escherichia coli was detected in samples of domestic radish sprouts at all stages from seed to storage, rape sprouts in the stages from soaked seed to storage, and red radish sprouts during sprouting, and no sanitizer was used in any of these processes. Untreated red radish sprouts were also positive for Bacillus cereus at all processing steps and Listeria monocytogenes after germination. However, pathogens were not detected at any sprouting stage of seeds treated with sanitizer. It is necessary to carefully control commercial sprouting, and to develop HACCP guidelines applicable to all sprouting processes, commencing at the first step in raw seed production.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.73-81
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• 2011

Six male crossbred (Thai Native${\times}$Anglo Nubian) goats, with an average initial weight of $22{\pm}2\;kg$, were randomly assigned according to a $3{\times}2$ factorial arrangement in a $6{\times}6$ Latin square design with a 21-d period to evaluate the effect of feeding rubber seed kernel (RSK) and palm kernel cake (PKC) in combination on nutrient utilization, rumen fermentation characteristics, and nitrogen utilization. The dietary treatments were as follows: i) concentrate containing 0% RSK and 20% PKC ($T_1$), ii) 0% RSK and 30% PKC ($T_2$), iii) 20% RSK and 20% PKC ($T_3$), iv) 20% RSK and 30% PKC ($T_4$), v) 30% RSK and 20% PKC ($T_5$), and vi) 30% RSK and 30% PKC ($T_6$). During the experiment, signal hay was given on an ad libitum basis as the roughage. It was found that RSK levels and PKC levels had no interaction effects on feed intake, apparent digestibility, $NH_3$-N, blood metabolites, VFA concentrations, and nitrogen utilization, but there were interactions between RSK levels and PKC levels with respect to total DMI (kg/d) and total VFA concentrations, and goats receiving 30% RSK had lower values (p<0.05) than those receiving 0 and 20% RSK, respectively. Feeding different PKC levels did not affect (p>0.05) feed intake, digestibility, rumen fermentation patterns, blood metabolites, and nitrogen utilization. However, increasing RSK levels (>20%) resulted in a slightly lower daily DMI (% BW and g/kg $BW^{0.75}$), apparent digestibility (NDF and ADF), total N intake, and N excretion than in goats fed on 0 and 20% RSK. BUN, blood glucose, and propionate were variable among treatment and were highest in 0% RSK with the 20% PKC fed group having values which were higher than those in other groups. However, there were no differences (p>0.05) among treatments with respect to N retention, PD output, and microbial N supply. Based on this study, RSK levels up to 20% and PKC at 20-30% in concentrate could be efficiently utilized for goats fed on signal hay.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.55-60
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• 2015

To secure the microbial safety of frozen strawberries, they were treated with the combined solution of aqueous chlorine dioxide and acetic acid prior to freezing and the effects of different freezing methods (at $-20^{\circ}C$ in a freezer, at $-70^{\circ}C$ in a gas nitrogen convection chamber, and at $-196^{\circ}C$ in liquid nitrogen) on the quality changes of strawberries were examined. Regarding the color of frozen strawberries, there were negligible changes among freezing treatments. In contrast, vitamin C content and sensory evaluation scores of strawberries frozen at $-70^{\circ}C$ were the highest among the samples. Drip loss of strawberries frozen at $-70^{\circ}C$ was the lowest as 14.39%, compared with strawberries frozen at -20 and $-196^{\circ}C$. In addition, the effects of combined treatment of 50 ppm chlorine dioxide and 1% acetic acid on the microbial growth in frozen strawberries were investigated, and the populations of preexisting microorganisms in the frozen strawberries were not detected by the combined pre-treatment. These results suggest that rapid freezing at $-70^{\circ}C$ using a gas nitrogen convection chamber is an appropriate freezing method for preserving quality of strawberries, and as a pre-freezing treatment, the combined treatment of aqueous chlorine dioxide and acetic acid can be effective for improving microbiological safety of frozen strawberries.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.635-641
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• 2012

The present study evaluated the effect of chitosan on the changes of soil chemical properties, soil microbial population, and yield of red pepper (Capsicum annuum L.) for eco-friendly agriculture in an upland field. We utilized four treatment groups, control, foliar spray, soil drench, and foliar spray + soil drench with chitosan, and analyzed these variations throughout the seven, fourteen, and twenty one days interval. The pH values, organic matter, and available phosphate in the upland soil at the harvesting stage decreased in the chitosan treatment. The populations of bacteria, actinomyces, and fungi in the upland field were increased in plots treated with chitosan. The chlorophyll content of leaves was no significant differences between the control and the chitosan treatments, while calcium content of leaves was significantly higher in the chitosan treatments than in the control. In addition, the nitrogen content of leaves was no significant differences between the foliar spray and the soil drench. The yield of red pepper was significantly higher in the control ($383kg\;10a^{-1}$) than the chitosan treatments and the yield of soil drench with chitosan reached up to 95% of control.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1087-1093
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• 2005

The population diversity and seasonal changes of bacterial communities in rice soils were monitored using both culture-dependent approaches and molecular methods. The rice field plot consisted of twelve subplots planted with two genetically-modified (GM) rice and two non-GM rice plants in three replicates. The DGGE analysis revealed that the bacterial community structures of the twelve subplot soils were quite similar to each other in a given month, indicating that there were no significant differences in the structure of the soil microbial populations between GM rice and non-GM rice during the experiment. However, the DGGE profiles of June soil after a sudden flooding were quite different from those of the other months. The June profiles exhibited a few intense DNA bands, compared with the others, indicating that flooding of rice field stimulated selective growth of some indigenous microorganisms. Phylogenetic analysis of l6S rDNA sequences from cultivated isolates showed that, while the isolates obtained from April soil before flooding were relatively evenly distributed among diverse genera such as Arthrobacter, Streptomyces, Terrabacter, and Bacillus/Paenibacillus, those from June soil after flooding mostly belonged to the Arthrobacter species. Phylogenetic analysis of 16S rDNA sequences obtained from the soil by cloning showed that April, August, and October had more diverse microorganisms than June. The results of this study indicated that flooding of rice fields gave a significant impact on the indigenous microbial community structure; however, the initial structure was gradually recovered over time after a sudden flooding.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1202-1208
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• 2009

Synbiotics is the term used for a mixture of probiotics (live microbial feed additives that beneficially affects the host animal) and prebiotics (non-digestible food ingredients that beneficially affect the organism). This study investigated the effect of probiotics from anaerobic microflora with prebiotics on growth performance, nutrient digestibility, noxious gas emission and fecal microbial population in weaning pigs. 150 pigs with an initial BW of 6.80${\pm}$0.32 kg (20 d of age) were randomly assigned to 5 dietary treatments as follows: i) US, basal diet+0.15% antibiotics (0.05% oxytetracycline 200 and 0.10% tiamulin 38 g), ii) BS, basal diet+0.2% synbiotics (probiotics from bacteria), iii) YS, basal diet+0.2% synbiotics (probiotics from yeast), iv) MS, basal diet+0.2% synbiotics (probiotics from mold), v) CS, basal diet+0.2% synbiotics (from compounds of bacteria, yeast and mold). The probiotics were contained in $10^{9}$ cfu/ml, $10^{5}$ cfu/ml and $10^{3}$ tfu/ml of bacteria, yeast and molds, respectively. The same prebiotics (mannan oligosaccharide, lactose, sodium acetate and ammonium citrate) was used for all the synbiotics. Pigs were housed individually for a 16-day experimental period. Growth performance showed no significant difference between antibiotic treatments and synbiotics-added treatments. The BS treatment showed higher (p<0.05) dry matter (DM) and nitrogen digestibility while ether extract and crude fiber digestibility were not affected by the dietary treatment. Also, the BS treatment decreased (p<0.05) fecal ammonia and amine gas emissions. Hydrogen sulfide concentration was also decreased (p<0.05) in BS, YS and MS treatments compared to other treatments. Moreover, all the synbioticsadded treatments increased fecal acetic acid concentration while the CS treatment had lower propionic acid concentration than the US treatment (p<0.05) gas emissions but decreased in fecal propionate gas emissions. Total fecal bacteria and Escherichia coli populations did not differ significantly among the treatments, while the Shigella counts were decreased (p<0.05) in synbiotics-included treatment. Fecal bacteria population was higher in the YS treatment than other treatments (p<0.05). The BS treatment had higher yeast concentration than YS, MS and CS treatments, while US treatment had higher mold concentrations than MS treatment (p<0.05). Therefore, the results of the present study suggest that synbiotics are as effective as antibiotics on growth performance, nutrient digestibility and fecal microflora composition in weaning pigs. Additionally, synbiotics from anaerobic microflora can decrease fecal noxious gas emission and synbiotics can substitute for antibiotics in weaning pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.7
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• pp.971-979
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• 2012

Four, lactating dairy crossbreds ($50%{\times}50%$ Holstein Friesian${\times}$Native Zebu cattle) were randomly assigned according to a $2{\times}2$ factorial arrangement (two protein levels and two levels of mangosteen peel pellets (Mago-pel)) in a $4{\times}4$ Latin square design to receive four dietary treatments. All cows received concentrate at a proportion of 1 kg concentrate per 2 kg of milk yield, and urea-treated 5% rice straw (UTRS) was given ad libitum. It was found that total dry matter intakes, nutrient digestibility, ruminal pH and $NH_3$-N concentrations were not affected (p>0.05) by treatments. Concentrations of ruminal pH and $NH_3$-N were not affected by dietary treatments although the concentration of BUN varied significantly (p<0.05) between protein levels (p<0.05). The populations of rumen bacteria and fungal zoospores did not differ among treatments (p>0.05); however, the population of protozoa was decreased (p<0.05) when cows received Mago-pel supplementation. The composition of the population of bacteria, identified by real-time PCR technique, including total bacteria, methanogens, Fibrobacter succinogenes and Ruminococcus albus was similar (p>0.05) among dietary treatments (p>0.05); however, copy numbers of Ruminococcus flavefaciens was increased when protein level increased (p<0.05). Microbial protein synthesis, in terms of both quantity and efficiency, was enriched by Mago-pel supplementation. Milk yield was greatest in cows fed UTRS based diets with concentrate containing protein at 16% CP with Mago-pel, but were lowest without Mago-pel (p<0.05). In addition, protein level and supplementation of Mago-pel did not affect (p>0.05) milk composition except solids-not-fat which was higher in cows fed the diet with 19% CP. Therefore, feeding a concentrate containing 16% CP together with 300 g/hd/d Mago-pel supplementation results in changes in rumen fermentation and microbial population and improvements in milk production in lactating dairy crossbreds fed on UTRS.

• Food Science and Preservation
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• v.16 no.2
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• pp.286-291
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• 2009

Microorganisms in seafood cooking drips were counted and identified. Total viable cell counts were 6.40 and 3.10 log CFU/g in cooking drips of Hizikia fusiformis and Thunnus thynnus, respectively. However, microbial populations fell with increased irradiation doses. In H. fusiformis cooking drips, a 5-log reduction in total aerobic bacteria was obtained by irradiation with 5 kGy. In T. thynnus cooking drips, however, contaminating microorganisms were more resistant to gamma irradiation and only a 1-log reduction was seen. DNA sequence analysis showed that the principal contaminating microorganisms in H. fusiformis and T. thynnus cooking drips were Lactobacillus and Bacillus species, respectively. Therefore, the high irradiation resistance of T. thynnus cooking drips microbes may result from spore formation by Bacillus species.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.709-718
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• 2006

In order to know the effects of Garlic, Scallion, Flavonoid, Urushiol, Anthocyanidin and Bio-MOS?? on pathogenic microbes and rumen anaerobic microbes, the growth rate of pathogens (including Escherichia coli O157, Salmonella paratyphi, Listeria monocytogenes and Staphylococcus aureus) and in vitro rumen microbial growth, gas production, ammonia concentration, carboxymethylcellulase(CMCase) activity, and microbial populations were investigated.The growth of pathogens was inhibited by supplementation of 0.1% Flavonoid, Scallion or Bio-MOS?? as biological active materials. And Scallion and Flavonoid had powerful antimicrobial properties on the pathogens applied in paper disc method.Although few effects by biological active materials disappeared in rumen fermentation in vitro, CMCase activity removed with supplementation of 1% of Flavonoid which had antimicrobial property in paper disc method. Scallion, having powerful antimicrobial property on pathogens and no inhibiting on rumen fermentation, might be a source in development of natural antimicrobial agent for ruminants.