• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1619-1626
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• 2014

This study was conducted to evaluate the effects of Joule heating and hydrostatic pressure on reduction of total aerobes and spores of Bacillus cereus in four kinds of sauces prepared with traditional Korean fermented foods. Total aerobes and inoculated spores of B. cereus in sauces were assayed after treatment or during storage at $30^{\circ}C$ after 4 or 8 weeks. Joule heating ($85^{\circ}C$), hydrostatic pressure (550 Mpa, 5 min), and antimicrobial additive (3% ethanol) were separately applied or combined as a hurdle technique. A 1.0~2.0 log reduction in total aerobes of Doenjang and Gochujang sauce was observed upon Joule heating at 80, 85, and $95^{\circ}C$. Significant reductions (0.92~1.21 log/0.5~1.38 log and 1.26~1.7 log/0.47~3.45 log) of total aerobes/spores of B. cereus in Doenjang and Gochujang sauce, respectively, occurred upon JA (Joule+additive), JP (Joule+hydrostatic pressure) or JAP (Joule+additive+ hydrostatic pressure). Effects of each treatments were maintained or increased during storage for 8 weeks at $30^{\circ}C$, suggesting that total aerobes and spores of B. cereus in Doenjang and Gochujang sauce can be controlled through Joule heating or hydrostatic pressure treatment.

• Korean Journal of Microbiology
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• v.3 no.1
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• pp.7-10
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• 1965

Higher number in colony counts in coliforms, total aerobes, and anerobes was obtained from marketable soy-bean mash than front that in fermented tank. The ratio between coliform contamination and total viable cells was higher in red pepper mash than in soy-bean mash. E. coli, contaminated in soy-bean mash persisted longer at low temperature ($0^{\circ}C$-$^5{\circ}C$) than at room temperature and they vanished after seven days of storage at room temperature. At 30.deg.C and 35.deg.C, these organisms were more effected than at room temperature. E. coli cells, inoculated in red pepper mash, were not recovered at room temperature after five days incubation. Soy-bean mash, completely fermented at normal conditions, were detected to contain $10^8$- $10^9$ organisms per gram of sample. On the contrary, marketable soy-bean mash were found to have more than 10$^{9}$ per gram samples. Since samples were found to have more than $10^9$ aerobes and anaerobes per gram, contamination of coliforms seemed to be apparent.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.545-550
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• 2001

Effects of high hydrostatic pressure on pH, titratable acidity, color, hardness and microorganisms of Chinese Cabbage Kimchi were investigated. Kimchi was pressurized at $200{\sim}600$ MPa for 5 min. There were no significant differences in color and hardness between control and pressurized Kimchi (p>0.05). Total aerobes and lactic acid bacteria were effectively inactivated by high hydrostatic pressure above 400 MPa. Changes in pH, titratable acidity, color, hardness and microbial counts for 4 weeks storage of Kimchi were investigated Kimchi was pressurized at 400 MPa for 5 min and stored at $4^{\circ}C$. The pH of control decreased to 3.94 but pressurized Kimchi maintained its initial pH value throughout the storage. The color of control showed significantly low values compared with pressureized Kimchi (p<0.05), but hardness was not significantly changed (p>0.05). Total aerobes and lactic acid bacteria in the control were reduced from the initial value of $10^8{\sim}10^9$ CFU/mL to $10^6$CFU/mL after 4 weeks storage. Whereas microbial counts in pressurized Kimchi was maintained about $10^3{\sim}10^4$ CFU/mL during storage.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.64-64
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• 1999

The relations between micorfloral compositions and environmental factors of 32 Korean infants were sought through statistical analysis after examination of fecal bacterial and questions to their mothers about feeding experiences at three different times for each subjects, about one week after birth, before weaning (2-3 months after birth), and after weaning 95-7 months after birth). The majority of mothers fed their infants cereal foods after the age of 4 months and began weaning with fruit juice and commercial weaning foods. Defection frequencies and fecal pH of infants decreased significantly during the examination period and 37.5% of total infants in fecal samples increased significantly during the examination period, which means that the kinds of bacterial genera increase with aging of infants. Frequencies of streptococci were significantly higher in infants fed delivered by Caesarian section than infants delivered naturally. Frequencies of clostridia were significantly higher in infants fed with cereal food before 4 months of age than after 5 months. The infants fed with probiotics showed significantly higher frequencies of veillonella at about 1 week old. They also showed significantly higher frequencies of clostridia before weaning than the infant fed with no probiotics, but significantly lower frequencies of C. perfringens before weaning. The infants fed with probiotics showed significantly higher number of streptococci at the age of about 1 week and significantly higher numbers of total aerobes before weaning, but significantly lower numbers of bacteroides after weaning than their counter parts. The fecal pH was directly proportional to the number of clostridia, klebsiella, and total aerobes at about 1 week after birth, to the number of E. coli before weaning, and to the number of streptococci and clostridia after weaning. Fecal pH had a negative relationship to the total number of anaerobes in 1-week-old infants. The infants that had diarrhea during lactation showed higher frequencies of bacteroides before weaning than those that didn't.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.67-74
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• 1999

The relations between micorfloral compositions and environmental factors of 32 Korean infants were sought through statistical analysis after examinaton of fecal bacterial and questions to their mothers about feeding experiences at three different times for each subjects, about one week after birth, before weaning (2-3 months after birth), and after weaning 95-7 months after birth). The majority of mothers fed their infants cereal foods after the age of 4 months and began weaning with fruit juice and commercial weaning foods. Defection frequencies and fecal pH of infants decreased significantly during the examination period and 37.5% of total infants in fecal samples increased significantly during the examination period, which means that the kinds of bacterial genera increase with aging of infants. Frequencies of streptococci were significantly higher in infants fed delivered by Caesarian section than infants delived naturally. Frequencies of clostrida were significantly higher in infants fed with cerealfood before 4 months of age than after 5 months. The infants fed with probiotics showed significantly higher frequencies of veillonella at about 1 week old. They also showed significantly higher frequencies of clostridia before weaning than the infant fed with no probiotics, but significantly lower frequencise of C. perfringens before weaning. The infants fed with probiotics showed significantly higher number of streptococci at the age of about 1 week and significantly higher numbers of total aerobes before weaning, but significantly lower numbers of bacteroides after weaning than their counter parts. The fecla pH was directly proportional to the number of clostridia, klebsiella, and total aerobes at about 1 week after birth, to the number of E. coli before weaning, and to the number of streptococci and clostridia after weaning. Fecal pH had a negative relationship to the total number of anaerobes in 1-week-old infants. The infants that had diarrhea during lactation showed higher frequencies of bacteroides before weaning than those that didn't.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.54-61
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• 1999

A study was conducted to find a rapid thawing method which prevents excessive drip loss and local overheating. Effects of thawing methods (conventional thawing vs. 2,450 and 915 MHz microwave thawing) on thawing time, temperature profile, drip loss, water holding capacity, total color difference and total aerobes were investigated. Samples were thawed at 4, 28 and $50^{\circ}C$ in a refrigerator or an oven for the conventional thawing methods the convertional thawing methods. Power levels of 5, 10 and 15 kW were used for 915MHz microwave thawing. Cotreatment of 915 MHz microwave and convectional heating $(120^{\circ}C)$ was tested. 915 MHz microwave accelerated the thawing rate, and showed significant effects on penetration depth, drip loss, water holding capacity and total aerobes. Cotreatment of 915 MHz microwave and convection heating was appeared to be a suitable thawing process for the food industry.

• Journal of Nutrition and Health
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• v.31 no.3
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• pp.305-314
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• 1998

Microflora in 14 breast-fed(BF) and 15 formula-fed(FF) infants were investigated before (2-3 months after birth) and after weaning (5-7 months birth) to find the floral differences between the two lactation groups and the floral changes after weaning. Bifidolbacteria showed the highest count among the species of microflora in the BF group before and after weaning, but in the FF group, streptococci showed the highest count before weaning and bifidobacteria after weaning. Before weaning , the count of bifidobacteria, lactobacilli and total acaerobes were significantly higher in the BF group than in the FF. However, the frequencies of clostridia and klesidella , along with the counts of streptococci and eubacteria, were higher in the FF group. After weaning , the only difference was that the total count of aerobic bacteria was higher in the BF group. The counts of streptococci in the BF group and lactobacilli and total anaerobes in the FF group after weaning were significantly higher than before weaning. However, the count of total aerobes in the FF group after weaning was significantly lower than the count before weaning.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.991-996
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• 1995

Effects of high hydrostatic pressure on microorganisms and browning enzymes in Angelica keiskei juice were investigated using response surface methodology. The optimum process condition for maximum reduction of total aerobes was $5700\;kg_f/cm^2$ (558.6 MPa) pressure and 7.16 min process time, and 3.44 log cycle reduction of total aerobes was predicted at the optimum condition. E. coli, initially $8.8{\times}10^3\;CFU/ml$, was completely inactivated by high hydrostatic pressure at all process conditions ($3800{\sim}6700\;kg_f/cm^2\;pressure;\;3{\sim}17\;min\;process\;time$). Polyphenol oxidase and peroxidase were partly inactivated by the high hydrostatic pressure. It was also indicated that inactivation of microorganisms and browning enzymes by hydrostatic pressure is dependent on pressure rather than process time.

• Journal of Microbiology
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• v.33 no.4
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• pp.273-277
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• 1995

Although trout farming is well established in Korea, very little information is available on the composition of intestinal microflora in rainbow trout (Salmo gairdnerii). In 1994, from October through November, we investigated the composition and succession of intestinal bacteria. As fish grew, total viable counts increased dramatically until 45 days after fertilization when anaerobes started to appear on the media. After this time, they increased steadily. Ten aerobic generic were identified and Gram negative bacteria constituted 85% of total isolates. Among these, Pseudomonas, Eikenella, and Alcaligenes were the three major genera. Six anaerobic genera were isolated and identified. The ratio of anaerobes to aerobes was about 1 : 1 in adult trout and the composition of genera was changed under different conditions.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.218-221
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• 2004

Irradiated red pepper powder (IRPP) was tested for its ability to retard fermentation and to maintain a high quality of Kimchi by the reduction of the initial microbial load. Kimchi containing IRPP at the doses of 0, 5, 10, 15, or 20 kGy was prepared. Quality indices for Kimchi in this study were pH, titratable acidity, reducing sugar content, total microbial count, lactic acid bacterial load, and sensory evaluation. Based on the pH and titratable acidity, the Kimchi with IRPP showed a retarded fermentation until 15 days. The number of the total aerobes and lactic acid bacteria of the Kimchi with IRPP were lower by about 1 log CFU/mL compared to control at day 0, however, the counts increased to 8.5 log CFU/mL after 10 days, which was similar to the control group. Kimchi that was fermented with 5 kGy IRPP was better than control and other treatments in odor and color, whereas the control scored highest in taste. Addition of IRPP showed a limited retardation of Kimchi fermentation without other quality deterioration.