• Food Engineering Progress
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• v.14 no.4
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• pp.328-334
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• 2010

Recently the enhancement and development of makgeolli processing to extend shelf life are constantly accomplished. However, the standardization to restrict microorganisms including cold chain system and sterilizing system has not been established yet. Therefore, the objective of this study was to investigate the storage stability of makgeolli using quick freezing (QF) and slow freezing (SF) storage methods. The storage period was 40 days. Every 10 days, the samples were taken from the quick and slow freezing storage chamber. And then the samples were put into a $10^{\circ}C$ refrigerator for 24 hr to thaw them. The final samples were evaluated for chemical experiments and microbial cell counts. As a result, reducing sugar content was dramatically increased after 10 days for all of the samples. In titratable acidity and color values case, these values did not significantly change by storage time. In case of lactic acid bacteria and yeasts for all the samples, there was a decreasing tendency with storage time. Especially, in case of lactic acid bacteria, the changes from the beginning microbial cell counts ($4.1{\times}10^7$ CFU/mL) for QF and SF after 20 days were $3.6{\times}10^6$ CFU/mL and $1.8{\times}10^4$ CFU/mL, respectively. This result showed that the freezing methods could restrict the microbial growth in makgeolli.

• Korean Journal of Medicinal Crop Science
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• v.2 no.3
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• pp.211-218
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• 1994

This experiment was conducted to obtain basic information for the establishment of in vitro initial culture system in Fritillaria thuubergii Miq. Methods of surface sterilization of scale segments as explant and effect of antibiotics added into the culture medium on contamination of explant and chilling treatment of mother bulb on bulblet formation were investigated. Portent of contamination of cultured scale segments was significantly higher in the outer scale segments which were unsuitable as initial culture explant than inner scale segments. Contamination of explants taken from inner scale of bulb was reduced by surface sterilizing explants in the solution of $4{\sim}5%$ sodium hypoclorite for $10{\sim}15$ mimutes. Addition of antibiotics such as kanamycin, vancomycia cefotaxim, agrirnycin and agreptomycin and dithane as fungicide and$lncyte^{tm}$ into MS medium was effective to reduce bateriological contamination, but did not work to control fungi. It had effective to delay the degree of contamination caused by fungi and bacteria haboring in cultured explants. Bulblet formation from cultured scale segments was promoted by dry storage for $2{\sim}4$ weeks or moisture storage of mother bulbs for $4{\sim}6$ weeks at $10^{\circ}C$ before excision of explants. Addition of kinetin into medium could not exerted for the bulblet formation from the scale segment of dry storaged bulb compared to control. But explant taken from 6 week moisture storaged bulb formed more than 10 bulblets per explant on the medium containing $3{\sim}5mg/L$ kinetin.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.1020-1033
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• 2020

This study attempted to investigate the usefulness of Rhus javanica L., Cinnamomum verum and Rosmarinus officinalis extracts which have antimicrobial and antioxidant effects without any harm on human health as natural preservatives. In terms of extraction, extraction by 70% ethanol and hot-water extraction were used for Cinnamomum verum and Rhus javanica L. respectively. For Rosmarinus officinalis, a mixed method (70% ethanol and hot-water extraction) was adopted. In terms of experimental methods, antimicrobial effects, antioxidant activity through DPPH and safety and stability of cosmetics were assessed, and a challenge test was performed, and the results found the followings: According to an antimicrobial test, good antimicrobial effects were found in bacteria (Rhus javanica L. extract) and fungi (Cinnamomum verum extract). In contrast, the Rosmarinus officinalis extract was set aside because of poor antimicrobial activity. In the mixed extract (Rhus javanica L. + Cinnamomum verum), antimicrobial effects were observed in 'complex C (mixed in a 1:1 ratio)' while both inhibitory and sterilizing effects were found in 5 different test strains at minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In addition, antioxidant effects were detected in non-mixed extract and mixed extract ('complex C'). Furthermore, a test on cosmetics which adopted '10% complex C' instead of synthetic preservative revealed safety and stability. Therefore, this study has confirmed the potential of the Rhus javanica L., Cinnamomum verum and Rosmarinus officinalis extracts as materials for natural preservatives.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.346-354
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• 2018

In the probe of a medical ultrasound device, three parts were selected randomly by the examiner and the bacteria in the probe were detected by the blood examiners. In addition, the degree of death of the pathogenic bacteria after each disinfection of the detected pathogens, disinfecting ethanol, and disinfecting tissue of the detected pathogens were analyzed quantitatively. The following was detected: S Aureus (32.3 %), Bacillus spp. (26.5 %), Micrococcus spp. (21.5 %), and CNS (20 %). With the conventional probe, S. aureus (26.2 %), a playback curve (24.2 %), and a micron (19.5 %), Micrococcus spp. (15.5 %), and CNS (14.6 %) were observed. In the fan probe, S. aureus (24.7 %), Enterococcus (24.7 %), Enterococcus (17.7 %), and CNS (13.8 %) were detected. The disinfection of the three pathogens detected revealed sterilization of most of the pathogens, and most cases contained at least 91.3 % of the total sterilizing effect (P>0.05). In addition, for the disinfection of Propolis extract and disinfecting tissue, the disinfection effect was lower than that of disinfecting ethanol, but the difference was not statistically significant (P>0.05). The results revealed bacteria on most of the ultrasound probes. Antiseptic disinfection of surgical instruments using an extract of propolis works with results similar to those of ethanol. A blood test along with disinfection can help prevent infection if an ultrasound probe is applied to food.

• Korean Journal of Food Science and Technology
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• v.1 no.1
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• pp.51-61
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• 1969

In order to eliminate the considerable loss of rice by insects, to protect the human body from toxin excreted by some microbes, and to promote the storage efficiency of rice by employing the irradiation, the following experiments were carried out. Two varieties of rice, Paldal and Nongkwang polished and unpolished by the conventional methods and were packaged in polyethylene bags. After irradiating to the doses of 6-400 Krad of gamma-radiation from a $Co-^{60}$ source the samples were stored at the room temperature $20^{\circ}C$ for 8 months. The effects of radiation in terms of the removal of insects and microbes and the changes of chemical components (such as moisture, amylose, free sugar, and rancidity) were determined monthly from march to October during the storage. 1) Infestation of insects was greatly influeneed by the packaging materials used. There was no infestation in rice being packaged in a polyethylene bag, while as the rice packaged in a straw sack was infested in two months of the storage. 2) Some yeast and molds survived 400 K rad of radiation. Sterilizing dose to inhibit reproduction and growth of microbes was presumed to be higher than 400 K rad. Yeast mainly were found on the surface of rice, but mold were embeded into rice kernels by mycelium. 3) Changes of moisture contents during storage was not affected by radiation but was by humidity of the storage room. 4) Amylose content in starch increased with increasing dose of radiation and with the length of storage time, indicating possible depolymerization of starch molecules. 5) Free reducing sugar content was not affected by radiation and decreased with storage time. 6) Rancidity also increased with does and storage time.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.359-363
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• 1983

Effects of irradiation on the physicochmical properties and its quality of powdered hot pepper paste which was used as a minor matrial of meat products, were investigated during the three months storage. Proximate components of powdered hot pepper paste were not remarkably changed according to the irradiation dose except the slight increase of total and reducing sugars. Capsanthin was insignificantly decreased by the increase of irradiation dose. Color difference according to the irradiation dose could not be distinguished by naked eye but was slightly changed by mechanical measurement. Total bacteria and E.coli were sterilized by the irradiation of 10kGy and 5kGy, respectively and no microorganisms were grown up after three months storage at $37^{\circ}C$. Sterilization of powered hot pepper paste by irradiation was expected to be superior to the traditional methods in the wholsomeness and sterilizing efficacy.

• Journal of Korean Academy of Nursing
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• v.23 no.3
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• pp.377-398
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• 1993

A survey of infant practices was conducted to provide information on which to base planned nursing interventions. The subjects were a convenience sample of 168 mothers visiting out - patients departments of five general hospitals and one public health center in Seoul for immunizations or treatment for common colds for their infants from two to 12 months of age. Data collection was carried out from July 8th to September 30th, 1991 using a questionnaire of 84 questions, 31 on the type of feeding, 22 on supplementary feeding and 21 on demographic infer mation. The results are summarized as follows : 1) The type of feeding was primarily artificial feed-ing (63.1%), followed by mixed feeding (22%) and breast feeding (14.9%) of the 59 mothers expecting during pregnancy to breast feed, 54. 2% changed artificial feeding and 30.5% went on to breast feed as they had expected. For mothers expecting to continue breast feeding over seven months. only one infant was being breast fed for over seven months. 2) For the 106 mothers using artificial feeding, 70. 8% hed attempted breast feeding, 64% of them for less than a month. Breast milk had been suppressed by for medication (38.7%) : 34.9% had used no specia] means. 3) The major reasons for replacing breast feeding with artificial feeding were the infants' demand for more milk (47.2% ) and insufficient supply of breast milk (49.3％). 4) Most mixed feeding was started at the age of one to three months (59.5%). Only 34.4% gave an artificial feeding after breast feeding : most (46%) alternated breast feeding with artificial feeding. On the whole, the motive for mixed feeding was the lack of breast milk (70.3%). 5) Many mothers (81.8%) were adding vitamin or mineral supplements to artificial milk and 51.5% were adding something to faciliate digestion. As for the method of sterilizing milk bottles and nipples, 56% had sterilized them together in boiling water from the beginning : 27% were just washing the bottles after boiling only once initially when measuring artificial milk powder, 31. 5% of the mothers over filled the measuring spoon rather than to the level. 6) The mother's occupation was related to her way of feeding. Mothers at home full time did more breast feeding than mothers employed outside the home. (x²=5.72, p=〈0.05). 7) Most mothers began supplementary food, from three to four months (48.8%) : 11.2% began later than seven months. Supplementary food was given between milk feedings by 67.2% of the mothers : 19.2% gave it before a milk feeding. Some mothers(26.4%) made their own supplementary food : 19.2% used ready - made supplementary food products for convenience. Recommendations for nursing interventions included : 1. Prenatal education about the advantages of breast feeding and breast care, and home visits after delivery for counselling related to breast feeding. Correct preparation of artificial feeding methods need to be taught in both pre & postnatal periods. In addition, specific education about supplementary feeding needed. 2. Further research is indicated about the Perceived lack of supply of breast milk and about the effectiveness of nursing interventions to Promote breast feeding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.2
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• pp.138-146
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• 2021

Objectives: This study aims to compare and evaluate the reduction efficiency of disinfectants used in the domestic meat processing industry to reduce bioaerosol exposure of meat industry workers and to use this as basic data for establishing work environment management measures. Methods: Thirteen disinfectants sold in South Korea were selected for evaluation and the bacterial reduction effect of the disinfectants was investigated. Bacterial suspension and surface disinfection tests were conducted to compare and analyze the antibacterial strength of the disinfectants. Pork carcasses, cutting boards, benches, and conveyor belts were selected for surface sterilization tests. Results: As a result of the bacterial suspension experiment test, all disinfectants had a bacterial reduction efficiency of more than 86%. Among them, the bacterial reduction efficiency of chlorine disinfectants was 99.93% on average. In the results of the pork carcass surface sterilization test, the rate of reduction of disinfectants made of quaternary ammonium compounds (QACs) was the highest. Tests of plastic cutting boards showed that chlorine disinfectants had the best sterilization effect. Experiments on stainless steel benches showed the best bacterial reduction efficiency for chlorine dioxide and QACs disinfectants. In the conveyor belt made of urethane, QACs disinfectants showed excellent sterilization effects. Conclusions: The study evaluated the disinfection power of disinfectants against bacteria occurring in domestic meat processing plants. All disinfectants were found to be effective in bacterial suspension experiments, and chlorine disinfectants were particularly effective. In surface sterilization experiments, sterilizing agents with QACs as the main ingredient were excellent.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.361-366
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• 2019

In this study, microbial contamivation semisulcospira libertine and effect of sedimentation treatment of major bacterial and fungal pathogens were investigated. The total aerobic bacteria, coliforms, Escherichia coli, Staphylococcus aureus, and yeast and mold present in raw and water-dipped Semisulcospira libertine were enumerated using the standard plate count methods on using the standard plate method on potato dextrose agar (PDA), 3M Petrifilm for coliforms / E. coli, 3M Petrifilm for S. aureus, and plate count agar (PCA), respectively. In analysis of microbial contamination of raw Semisulcospira libertine, the total aerobic bacteria, coliforms, and yeast and mold were monitored as 6.40, 2.70, and $6.79{\log}_{10}CFU/g$, respectively. Both E. coli and S. aureus were not detected (detection limit: 10 CFU/g). However, Semisulcospira libertine dipped in ground water for 3 hours had higher contamination levels of all natural indigenous microorganisms than raw Semisulcospira libertine. Especially, E. coli was detected as $2.46{\log}_{10}CFU/g$ in the ground water-dipped Semisulcospira libertine. The total aerobic bacteria in the ground water-dipped Semisulcospira libertine was not significantly reduced (p>0.05) compared to that in the raw Semisulcospira libertine. Moreover, coliforms were significantly increased (p>0.05) in all water-dipped Semisulcospira libertine. Only fungi were slightly reduced (less than 0.2 log) (p>0.05) in the tap water-dipped Semisulcospira libertine by comparison with the raw Semisulcospira libertine. The results of this study suggest that the use of chemical sterilizing agents and other physical methods in the washing stage will be necessary for the microbial reduction in raw Semisulcospira libertine because the use of sediment removal treatment by ground or tap water did not affect the microbiological safety of the raw Semisulcospira libertine.