• Title/Summary/Keyword: microbial risk

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Principles and Applications of Non-Thermal Technologies for Meat Decontamination

  • Yewon Lee;Yohan Yoon
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.19-38
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    • 2024
  • Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

Toll-like Receptors in Host Defense and Immune Disorders

  • Lee, Joo-Y.
    • Toxicological Research
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    • v.23 no.2
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    • pp.97-105
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    • 2007
  • Toll-like receptors (TLRs) playa crucial role in initiating and regulating innate and adaptive immune responses by detecting invading microbial pathogens. TLRs can also respond to non-microbial molecules derived from damaged tissue. Accumulating evidence suggests that deregulation of TLRs results in the dysfunction of immune system and ultimately increases the risk of many immune and inflammatory diseases including infectious diseases, allergy, and autoimmune diseases. Therefore, understanding how the immune system is controlled by TLRs will provide new insight to find the way to prevent or treat infectious diseases and immune disorders.

Dietary Diversity during Early Infancy Increases Microbial Diversity and Prevents Egg Allergy in High-Risk Infants

  • Bo Ra Lee;Hye-In Jung;Su Kyung Kim;Mijeong Kwon;Hyunmi Kim;Minyoung Jung;Yechan Kyung;Byung Eui Kim;Suk-Joo Choi;Soo-Young Oh;Sun-Young Baek;Seonwoo Kim;Jaewoong Bae;Kangmo Ahn;Jihyun Kim
    • IMMUNE NETWORK
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    • v.22 no.2
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    • pp.17.1-17.14
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    • 2022
  • We aimed to investigate associations of dietary diversity (DD) with gut microbial diversity and the development of hen's egg allergy (HEA) in infants. We enrolled 68 infants in a high-risk group and 32 infants in a control group based on a family history of allergic diseases. All infants were followed from birth until 12 months of age. We collected infant feeding data, and DD was defined using 3 measures: the World Health Organization definition of minimum DD, food group diversity, and food allergen diversity. Gut microbiome profiles and expression of cytokines were evaluated by bacterial 16S rRNA sequencing and real-time reverse transcriptase-polymerase chain reaction. High DD scores at 3 and 4 months were associated with a lower risk of developing HEA in the high-risk group, but not in the control group. In the high-risk group, high DD scores at 3, 4, and 5 months of age were associated with an increase in Chao1 index at 6 months. We found that the gene expression of IL-4, IL-5, IL-6, and IL-8 were higher among infants who had lower DD scores compared to those who had higher DD scores in high-risk infants. Additionally, high-risk infants with a higher FAD score at 5 months of age showed a reduced gene expression of IL-13. Increasing DD within 6 months of life may increase gut microbial diversity, and thus reduce the development of HEA in infants with a family history of allergic diseases.

Ethanolamine and boron abuse to limit microbial growth in water-synthetic metalworking fluids (미생물 성장을 억제하기 위하여 수용성 절삭유에 과다하게 첨가한 붕소와 아민 사례 연구)

  • Park, Donguk;Paik, Dohyeon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.15 no.3
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    • pp.270-276
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    • 2005
  • This study was conducted to examine whether a specific synthetic metalworking fluid (MWF), "A", in use for 10 months without replacement, displayed microbial resistance and to identify the additives associated with the control of microbial growth. Three synthetic MWF products ("A", "B", and "C") were studied every week for two months. Microbial deterioration of the fluids was assessed through evaluation by endotoxin, bacteria and fungi levels in the MWFs. In addition, formaldehyde, boron, ethanolamine, and copper levels were also studied to determine whether they influence microbial growth in water-based MWFs. Throughout the entire study in the sump where MWF "A" was used, bacteria counts were lower than 103 CFU/mL, and endotoxins never exceeded 103 EU/mL. These levels were significantly lower than levels observed in sumps badly deteriorated with microbes. Boron levels in MWF "A" ranged from 91.7 to 129.6 ppm, which was significantly higher than boron levels found in other MWF products. The total level of ethanolamine (EA) in MWF "A" ranged from 35,595 to 57,857 ppm (average 40,903 ppm), which was over ten times higher than that found in other MWFs. Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) concentrations in MWF "A" were also significantly higher than seen in other MWFs. However, although EA and boron might improve anti-microbial performance, their abuse can pose a serious risk to workers who handle MWFs. From an industrial hygiene perspective, our study results stress that the positive synergistic effect of boron and EA in reducing microbial activity in MWF must be balanced with the potentially negative health effects of such additives. Our study also addresses the disadvantage of failing to comprehensively report MWF additives on Material Safety Data Sheets (MSDS). Future research in MWF formulation is needed to find the best level of EA and boron for achieving optimal synergistic anti-microbial effects while minimizing employee health hazards.

Microbial Risk Assessment and HACCP Plan for the Safe Production of Dry Aged Meat (안전한 건식 숙성육 제조를 위한 미생물 위해평가 및 HACCP 적용 방안)

  • Oh, Hyemin;Lee, Hyun Jung;Jo, Cheorun;Yoon, Yohan
    • Journal of the FoodService Safety
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    • v.3 no.1
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    • pp.8-18
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    • 2022
  • Dry-aging is one of the traditional aging processes, especially for beef. This aging process is being popular, because it produces unique brown/roasted flavor and texture that consumers prefer. However, as it is exposed to outside without packaging food safety concerns have been raised. The objective of this study was to investigate the presence of total aerobic bacteria (TAB) and pathogenic bacteria in manufacturing environment and suggest the safety management plan for the production of dry-aged meat. Surface samples from 66 environmental and 6 beef carcass samples were collected. According to the monitoring results, the contamination levels of TAB were in the order of shelves (5.4±1.1 Log CFU/cm2), cotton gloves (2.9±0.2 Log CFU/cm2), and door knobs (2.8±0.4 Log CFU/cm2) in the dry-aging room. In the door knobs, the level of mold was higher than that of yeast. These results indicate that the mold spores may be cross-contaminated with environmental factors inside the aging room. The risk factors that may occur during the manufacturing process were presented and possibility of risk was determined. From the aspect of microbiology, aging and trimming steps were determined as the critical control points. The temperature of the aging room should be maintained below 10℃ and the humidity below 75-85%. Based on the monitoring and the risk assessment of the dry-aging process, we prepared the safety management plan for the production of dry-aged meat, and it should be useful in improving the food safety of dry-aged meat.

Irrigation with Microbial-Contaminated Water and Risk of Crop Contamination (미생물 오염 용수 관개에 의한 작물의 오염 위험성)

  • Choi, C. Yeon-Sik;Song, In-Hong;Kwun, Soon-Kuk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.2
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    • pp.87-97
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    • 2007
  • The aim of this study was to compare crop contamination between two irrigation methods using microbial-contaminated water. The effect of relative humidity on microbial survival of the three indicator microorganisms was also investigated. Escherichia coli ATCC 25922, Clostridium perfringens ATCC 3624, and coliphage PRD1 were applied to irrigation water to grow cantaloupe, lettuce, and bell pepper. Half of the sixteen plots were subsurface drip irrigated (SDI) and the other half were furrow irrigated (FI). Two relative humidity levels were controlled at 15-65 % and 55-80 % for the dry and humid condition experiments, respectively. Samples of produce, surface soil, and subsurface soil at a depth of 10 cm were collected over a two-week period following the application of the study microorganisms. Overall, greater contamination of both produce and soil occurred in the FI plots. For the SDI plots, preferential water paths and resulting water appearance on the seed beds seemed to be responsible for produce contamination. Relative humidity levels did not appear to affect microbial survival in soil. PRD 1 showed lower inactivation rates than 5. coli in both dry and humid conditions. C. perfringens did not experience significant inactivation over the experimental period, suggesting this microorganism can be an effective indicator of fecal contamination.

Changes in the Microbial Qualites and Sensory Characteristics of Boiled Potatoes and Imitation Crab Sticks in Soy Sauce as Prepared by the Cook-Chill System and Sous Vide Cook-Chill System (Cook-chill System과 Sous vide Cook-chill System으로 생산된 감자게맛살 조림의 저장기간에 따른 미생물학적 품질과 관능특성의 변화(1))

  • Kim, Heh-Young;Song, Sun-Mi
    • Korean journal of food and cookery science
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    • v.23 no.2 s.98
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    • pp.252-260
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    • 2007
  • This study was performed to provide basic data for the operation of the sous vide cook-chill system(SVCC) by comparing and evaluating the quality of SVCC prepared foods to those prepared using the cook-chill system(CC). Foremost, the microbial risk was less and the food quality excellent when SVCC was used compared to CC, where changes in pH, Aw and moisture loss were less with SVCC. The CC and SVCC Aw value were 0.93 and 0.92 and 0.92 and 0.95 at 0 days and 15 days, respectively. Secondly, the microbial quality by storage days was relatively high with SVCC. The CC and SVCC viable cell and coliform counts were 4.43 and 4.37 LogCFU/g, and 4.53 and 3.60 LogCFU/g, respectively, by 15 days. Also, after reheating, the viable cell and coliform counts satisfide the standards applied in processed food(5.0 and 2.0 LogCFU/g respectively). Lastly, the sensory scores for SVCC were higher than those for CC. Thus, microbial and sensory qualities by days of storage were acceptable and overall quality satisfaction was better for SVCC than CC.