• Title/Summary/Keyword: sterilization of microorganisms

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Evaluation of Quality Properties of Gamma-irradiated Freeze-dried Fruits (감마선 조사에 따른 동결건조과일의 품질 특성 평가)

  • Choi, Soo-Jeong;Yoon, Young-Min;Han, In-Jun;Kim, Jae-Kyung;Park, Jong-Heum;Lee, Ju-Woon;Lyu, Eun-Soon;Yook, Hong-Sun;Kim, Jae-Hun;Song, Beom-Seok
    • Journal of Radiation Industry
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    • v.6 no.4
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    • pp.299-304
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    • 2012
  • The quality properties of freeze-dried apples, pears, strawberries and pineapples gamma-irradiated at 0, 1, 2, 3, 4, and 5 kGy were evaluated to develop germ-free products for immuno-compromised patients. The initial count of total aerobic bacteria in non-irradiated apples, pears, strawberries and pineapple was 2.5, 3.1, 2.6, and $3.2{\log}\;CFU{\cdot}g^{-1}$, respectively. Microorganisms were not observed in apples after 1 kGy, in pears and strawberries after 4 kGy, and in pineapples at 5 kGy within a detection limit of $10{\log}\;CFU{\cdot}g^{-1}$. In addition, the sterilization of each sample was confirmed at the same dose. The score for the overall acceptance of freeze-dried fruit irradiated at a sterilization dose was 5.5 for apples, 4.1 for pineapples, and 4.0 for the other fruits, whereas that of non-irradiated control sample was 5.6 for apples, 5.2 for pears, and 5.8 for strawberries and pineapples with a 7-point scale. As a result, gamma irradiation of 1 kGy for apples, 4 kGy for strawberries and pears, and 5 kGy for pineapples is sufficient to sterilize each freeze-dried fruit with acceptable sensory properties.

Microbiological Hazard Analysis for HACCP System Application to fermented milk (발효유류의 HACCP 시스템 적용을 위한 미생물학적 위해 분석)

  • Park, Seong-Bin;Kwon, Sang-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.438-444
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    • 2015
  • The aim of this research was to apply a HACCP system (Hazard Analysis Critical Control Point) to fermented milk. The main ingredients of fermented milk, work facilities and workers were obtained from a company named YD, which is located in Seobuk-gu, Cheonan-si between November 5 2013 to April 13, 2014. A manufacturing process chart was prepared by referring to the manufacturing process of fermented milk manufacturers in common. The manufacturing process chart was made with raw materials; Raw milk, High Fructose Corn Syrup, Oligosaccharides, Lactic Acid bacteria and Subsidiary ingredients, Warehousing of packaging materials, Storage, Input, Preheating, Mixing, Homogeneity, Sterilization, Precooling, Culture, Filtration, In packaging, Out packaging, Storage, and Consignment, as listed Table 1. The results of the microbiological hazard analysis on the raw materials was safe after sterilization($90^{\circ}C{\pm}5^{\circ}C$, $35{\pm}3min.$) On the other hand,a microorganism test of an environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by improved personal hygiene based on hygienic education on workers and the management of microorganisms in air.

Sterilization of Rapeseed Sprouts by Intense Pulsed Light Treatment (고강도 광원을 이용한 새싹 채소의 살균)

  • Park, Heeran;Cha, Gyung-Hee;Shin, Jung-Kue
    • Korean Journal of Food Science and Technology
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    • v.48 no.1
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    • pp.36-41
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    • 2016
  • In this study, the effects of intense pulsed light (IPL) treatment on microbial inactivation and quality in rapeseed sprouts were investigated. Untreated rapeseed sprouts exhibit a high level of total aerobic bacteria (TAB) ($1.2{\times}10^7CFU/g$), coliform bacteria (coliform) ($3.3{\times}10^6CFU/g$), and pathogenic E. coli (PE) ($2.1{\times}10^5CFU/g$). The microorganisms found on rapeseed sprouts decreased with exposure to increasing light intensity and treatment time. The greatest reduction in microbial content was observed with a treatment of 1000 V, 5 pps for 10 min, where TAB, coliform, and PE levels decreased to 1.0 log CFU/g, 1.6 log CFU/g, and 1.8 log CFU/g, respectively. In agreement with these data, the microbial inactivation rate increased with the increase in the distance between the light source and the samples during IPL treatment. After IPL treatment of rapeseed sprouts, water content and vitamin C content decreased.

Combined Effect of Heat Treatment and Gamma Irradiation on the Shelf-Stability and Quality of Packaged Kimchi during Accelerated Storage Condition (가열 및 감마선 조사 병용처리가 가속저장 포장 김치의 저장안정성 및 품질에 미치는 영향)

  • Kim, Mi-Jung;Park, Jin-Gyu;Kim, Jae-Hun;Park, Jae-Nam;Lee, Hyun-Joo;Kim, Wang-Geun;Lee, Ju-Woon;Byun, Myung-Woo
    • Food Science and Preservation
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    • v.13 no.5
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    • pp.531-537
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    • 2006
  • This study was conducted to evaluate the combined effect of heating and gamma irradiation on the shelf-stability and quality of kimchi during storage at $35^{\circ}C$. The optimum condition for heat treatment of kimchi was considered at $60^{\circ}C$ for 30 min. Irradiation after kent treatment was effective to inhibit the growth of microorganisms and prevent the quality change of kimchi during storage. In particular, microorganisms of kimchi co-treated with heat and 20 kGy-irradiation were not detected and sensory scores of that were the highest after storage at $35^{\circ}C$ for 14 days. Therefore, combination treatment of heat and irradiation was considered as the effective method to improve the shelf-stability of kimchi in the accelerated condition.

Irradiation of Korean Beef for the Improvement of Hygienics and Quality Preservation (감마선을 이용한 한우육의 위생화와 품질보존)

  • Kwak, Hee-Jin;Kang, Il-Jun
    • Korean Journal of Food Science and Technology
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    • v.32 no.2
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    • pp.363-372
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    • 2000
  • Gamma irradiation$(1{\sim}5\;kGy)$ was applied to Korean beef to improve the hygienics and quality preservation. The effective dose of irradiation was 3 kGy for the sterilization of the initially contaminated microorganisms. After 8 weeks of storage at $5^{\circ}C$, no growth of the microorganisms were observed in the samples irradiated above 5 kGy. The pH was slightly increased as storage period increased. However, no significant change in pH was observed by gamma irradiation. The acid value of beef during storage at $5^{\circ}C$ was increased rapidly with the elapse of the storage period in both nonirradiated and irradiated samples, but that of the 3 kGy irradiated samples increased more slowly than the nonirradiated. VBN value increased more rapidly in nonirradiated sample than the irradiated during storage. Especially VBN value of the nonirradiated sample was four fold higher than that of the 3 kGy irradiated sample after 8 weeks of storage at $5^{\circ}C$. No significant differences in the components of fatty acid were observed by gamma irradiation. The amount of released free amino acid was increased during storage and was not significantly affected by gamma irradiation.

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Radicidation of the Condiment for Soup of Instant Noodle(Ramen) (즉석라면 스-프의 감마선 살균)

  • Byun, Myung-Woo;Kwon, Joong-Ho;Cha, Bo-Sook;Cho, Han-Ok;Kang, Se-Sik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.18 no.1
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    • pp.14-18
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    • 1989
  • Comparative effects of gamma irradiation and ethylene oxide treatments on the sterilization and physicochemical propperties of the condiment for soup of instant noodle (ramen) were investigated. The number of microorganisms contaminated ranged from $10^3\;to\;10^7\;CFU/g$ in total bacterial count, which were mainly composed of thermophiles and acid tolerant bacteria by over 90%. The yeast & molds were contaminated by $10^2\;to\;10^3\;CFU/g$. In the sterilizing effect of an irradiation on the microorganisms contaminated, 7 to 10 kGy gamma irradiation could eliminated yeast & molds, and also bring about the reduction of total bacterial count to below $10^3\;CFU/g.\;D_{10}$values of total bacteria! count of the samples ranged from 2.33 to 3.33 kGy. In comparative effects of irradiation and ethylene oxide treatments on the physicochemical properties of the sample, both treatments affected more or less rancidity, color, and amino-Ncontent, but less than 10 kGy irradiation was shown to be safe than ethylene oxide.

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Comparison of Microbiological Safety of Porcine Grafts on Gamma Irradiation for Use of Xenografts (돼지 유래 생체 조직의 이식재 활용을 위한 방사선 조사 미생물 제어 평가)

  • Jo, Eu-Ri;Kim, Jeongsoo;Choi, Jong-il;Kim, Jae-Hun;Sung, Nak-Yun;Song, Beom-Seok;Kim, JaeKyung;Park, Jong-Heum;Lee, Ju-Woon
    • Journal of Radiation Industry
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    • v.5 no.3
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    • pp.279-283
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    • 2011
  • This study was compared microbiological safety with gamma-irradiated porcine tendon and skin, as materials for the development of xenografts to regenerate damaged tissues and protect secondary contamination. The porcine tendon and skin were gamma-irradiated after inoculation of bacteria and virus to evaluate irradiation sensitivity of microorganisms. The result showed that the porcine tendon and skin were not different on the sensitivity of microorganisms by gamma irradiation. Bacteria inoculated in the porcine tendon and skin were confirmed that E. coli was the $D_{10}$ values of $0.32{\pm}0.082$ and $0.25{\pm}0.1kGy$ on tendon and skin, and B. subtilis was $4.00{\pm}0.312$ and $3.88{\pm}0.3kGy$ on gamma irradiation, respectively. Moreover, Virus inoculated in the porcine tendon and skin was observed that poliovirus (PV) was $6.26{\pm}0.332$ and $6.88{\pm}0.3kGy$, and porcine parvovirus (PPV) was $1.75{\pm}0.131$ and $1.73{\pm}0.2kGy$ and bovine viral diarrhoea virus (BVDV) was $3.70{\pm}0.212$ and $3.81{\pm}0.2kGy$ on gamma irradiation, respectively. Virus showed higher resistance compared to bacteria on gamma irradiation, but was not detected CPE (cytopathic effect) by virus both tendon and skin at 25 kGy, a standard dose recommended from IAEA for sterilization of medical products. Therefore, These results were considered that gamma irradiation could control effectively bacteria and virus to develop safe porcine xenograft, and apply same irradiation doses to all tissues including tendon and skin of porcine.

Inactivation Efficiency of Escherichia coli and Listeria monocytogenes in Ground Pork by Combination of Natural Food Ingredients and High Pressure Processing

  • Jung, Samooel;Yun, Hye-Jeong;Kim, Hyun-Joo;Ham, Jun-Sang;Kim, Il-Suk;Lee, Moo-Ha;Jo, Cheorun
    • Food Science of Animal Resources
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    • v.32 no.1
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    • pp.1-5
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    • 2012
  • The objective of this study was to examine the effects of a combined treatment regarding antimicrobial food ingredients and high pressure processing (HP) on the inactivation efficiency of Escherichia coli and Listeria monocytogenes inoculated into ground pork. Ethanol extracted from garlic, leeks, onions, and ginger powder was prepared. Half of the prepared powder was irradiated at 5 kGy to see the effect of pasteurization before addition. The prepared food ingredients were added into radiation-sterilized ground pork (1%, w/w), and inoculated with E. coli and L. monocytogenes. The samples were vacuum-packed and applied with HP at 0.1 (control), 300, 450, and 600 MPa. Microbial log reduction increased with the increase of pressure up to 600 MPa. With minor exceptions, overall efficiency of HP treatment with regards to inactivation of pathogens increased. Inoculated microorganisms showed approximately 7-8 Log reductions by 600 MPa, except for L. monocytogenes treated with garlic (5.7 Log reductions). The E. coli reduction in ground pork mixed with ethanol extracted garlic showed the highest efficiency (1.86) compared to leeks (1.25-1.31), onions (1.17-1.44), and ginger (1.50-1.82) when treated at an HP of 450 MPa. There was no evidence for the advantage of pasteurization concerning the food ingredients before addition of antimicrobial food ingredients and HP. Results demonstrate that the combination of antimicrobial food ingredients and HP treatment may help improve the efficiency of sterilization in meat systems.

Physiological Response of Panax Ginseng to Tcmpcrature II. Leaf physiology, soil temperature, air temperature, growth of pathogene (인삼의 온도에 대한 생리반응 II. 엽의 생리, 지온, 기온, 병환의 생육)

  • Park, Hoon
    • Journal of Ginseng Research
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    • v.4 no.1
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    • pp.104-120
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    • 1980
  • The effects of temperature on transpiration, chlorophyll content, frequency and aperture of stomata, and leaf temperature of Panax ginseng were reviewed. Temperature changes of soil and air under spade roof were also reviewed. Growth responses of responses of ginseng plant at various temperature were assessed in relation to suseptibillity of ginseng plants. Reasonable management of ginseng fields was suggested based on the response of ginseng to various temperatures. Stomata frequency may be increased under high temperature during leaf$.$growing stage. Stomata aperture increased by high temperature but the increase of both frequency and aperture appears not enough for transpiration to overcome high temperature encountered during summer in most fields. Serial high temperature disorder, i.e high leaf temperature, chlorophyll loss, inhibition of photosynthesis, increased respiration and wilting might be alleviated by high humidity and abundant water supply to leaf. High air temperature which limits light transmission rate inside the shade roof, induces high soil temperature(optimum soil temperature 16∼18$^{\circ}C$) and both(especially the latter) are the principal factors to increase alternaria blight, anthracnose, early leaf fall, root rot and high missing rate of plant resulting in poor yield. High temperature disorder was lessen by abundant soil water(optimum 17∼21%) and could be decreased by lowering the content of availability of phosphorus and nitrogen in soil consequently resulting in less activity of microorganisms. Repeated plowing of fields during preparation seems to be effective for sterilization of pathogenic microoganisms by high soil temperature only on surface of soils. Low temperature damage appeared at thowing of soils and emergence stage of ginseng but reports were limited. Most limiting factor of yield appeared as physiological disorder and high pathogen activity due to high temperature during summer(about three months).

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An Efficient in vitro Micropropagation for Production of Disease-free Bulbs in Korean Native Lilium

  • Song, Jae-Young;Yi, Jung-Yoon;Yoon, Mun-Sup;Lee, Jung-Ro;Lee, Young-Yi
    • Korean Journal of Plant Resources
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    • v.32 no.6
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    • pp.730-734
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    • 2019
  • Cryopreservation is one of the ideal and suitable methods for long-term storage of plant germplasm. The plant contaminated with diseases and pathogens are decreased the multiplication rate, survival rate and high quality of plants after cryopreservation. The aim of this work was to improve a micropropagation method for lily in Korea, which is indigenous plant. In the last process of rinsing scales after surface-sterilization, we tried to control the diseases and pathogens lived within the tissue by rinsing in 0.03% sodium hypochlorite (NaClO) instead of sterile distilled water. Bulb scales of Lilium were cultured in vitro on MS medium supplemented with Plant Preservative Mixture (PPM). The results showed that L. tsingtauense accessions were observed ranged from 53.9 to 100% with a mean value of 76.8% and L. hansonii accessions were checked from 84.5 to 85.5% with a mean of 85% survival rate. The newly small bulb formed from bulb-scales was transferred to MS medium. We checked the presence of microorganisms and survival rate after 3 weeks in culture after examination of bacterial incidences. The results indicated that the non-contamination rate were shown ranged from 75.0 to 94.1% with mean value of 83.2% in L. tsingtauense species, and that L. hansonii were observed 85.1 to 91.7% with mean value of 88.4%. This study will provide a valuable basis for establishment of effective axenic cultures for in vitro micropropagation of Korean native lily species.