• Title/Summary/Keyword: microbial counts

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Preservation of Washed Fresh Ginsengs by Gamma Irradiation (방사선(放射線) 조사(照射)에 의한 수세된 수삼(水蔘)의 저장(貯藏))

  • Cho, Han-Ok;Byun, Myung-Woo;Kwon, Joong-Ho;Lee, Jae-Won
    • Applied Biological Chemistry
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    • v.29 no.3
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    • pp.288-293
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    • 1986
  • The washed fresh ginsengs packed with air, vaccum and nitrogen gas were irradiated at the levels of 1,2 and 3kGy gamma radiation and then stored at $4{\sim}5^{\circ}C$ for 90days to investigate the effects of gamma radiation on microbial inactivation, eelworm disinfestation and physicochemical changes. After a 90 day storage, $2{\sim}3kGy$ irradiated groups showed 20% of weight loss and 10% of rot while non-irradiated group 100% and 20% or more, respectively. Also the irradiated groups showed somewhat lower values of specific gravity, color density and hardness immediately after irradiation, thereafter higher value of them with storage time than those of non-irradiated group. The irradiation increased the yields of ginseng extract and crude saponins but no effects on the proximate composition and TLC and HPLC patterns of saponin. The food-borne microorganisms decreased in viable cell counts by $2{\sim}3$ log cycles with $2{\sim}3kGy$ radiation and the eelworms were completely disinfested with 1 kGy radiation.

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Changes of Major Components and Microorganisms during the Fermentation of Korean Ordinary Kochujang (한국재래식(韓國在來式)고추장숙성중(熟成中)의 주요성분(主要成分) 및 미생물(微生物)의 변화(變化))

  • Ahn, Cheol-Woo;Sung, Nack-Kie
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.16 no.3
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    • pp.35-39
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    • 1987
  • The present study was attempted to obtain the basic data concerning a reasonable preparing method and the optimum fermentation conditions of Kochujang (Red pepper paste). To establish the standard qualify of Kochujang, changes of the chemical composition and the numbers of bacteria and feasts in Kochujang during fermentation were observed. Moisture, salts and crude ash contents of Kochujang were not changed significantly during fermentation. Titrable acidity and amino nitrogen gradually increased with the time-passed, whereas crude fat gradually decreased with the time-elapsed. And reducing sugar and total nitrogen increased until 40 days, but slightly decreased after this period. The numbers of bacteria and yeasts in the ingrients for the preparation of Kochujang were $3.9{\times}10^7/g$, $1.5{\times}10^3/g$ in red pepper powder, $7.6{\times}10^4/g$, $2.8{\times}10^2/g$ in salts. respectively, but those of sugar and malt were not more than 100/g. Microbial counts in Kochujang during fermentation increased until 40 days, but those are gradually decreased after that.

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Chemical and Functional Characteristics of Mechanically Deboned Chicken meat and its Utilization in Processed Meat (기계발골가금육의 특성 및 이용에 관한 연구)

  • 김종원;안병윤;이유방
    • Korean Journal of Poultry Science
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    • v.7 no.2
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    • pp.37-46
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    • 1980
  • Hand deboned and mechanically deboned chicken meat were produced from domestic broilers and spent layers. Meat yield, chemical composition, functional characteristics, stability during storage, and microbiological properties were investigated Chicken patties and frankfurters were also manufactured by varying the relative proportion of MDCM to HDCM as raw materials, ana their palatability, shelf-life and textural properties were evaluated. The obtained results were as follows: 1) 35% of carcass wt was recovered as HDCM and 45% as MDCM, total meat yield reaching 80% of carcass wt. 2) Moisture, protein, fat, ash and Ca content of MDCM were 65, 12, 20, 1.7 and 0.2-0.4%,respectively. MDCM was higher in fat, ash and Ca, but significantly lower in moisture and protein. Total pigment content of MDCM was 2.5 times higher than that of HDCD such high content being attributed to the increased inclusion of hemoglobin. 3) The emulsifying capacity (ES) of MOCM per g meat was only 70% that of HDCM. but when ES was expressed on unit g of protein basis MDCM showed even higher ES than HDCM primarily due to tile higher proportion of salt soluble protein fraction. 4) Since the TBA values of MDCM increased rapidly after 4 weeks of frozen storage at -20$^{\circ}C$, the maximum possible storage period of MDCM is estimated to be about 4 weeks. 5) Total microbial counts of MDCM was approximately 1.8${\times}$10$\^$6/g/, showing no great difference from HDCM or red meat. 6) Chicken patty containing MDCM showed gradual increase in TBA value during frozen storage, but its storage up to 8 weeks presented no problems in flavor stability. 7) Color score an4 total palatability of chicken Patty were best for the product containing 30% MDCM. It was also concluded that MDCM can be included in the patties up to 50% of total meat with good results, but more than 70% was not recommended 8) The formulation of MDCM up to 50% in frankfurter gave quite satisfactory acceptability and textural properties comparable to frankfurter made of 100% MDCM, but the inclusion of more than 70% MDCM was not recommended 9) The TBA value of frankfurter containing MDCM did not increase to any great extent until 4 weeks of storage at 4$^{\circ}C$, indicating no unique problems in flavor instability compared to regular frankfurter. 10) It was concluded that processed meat products such as patties and frankfurters containing MDCM up to 30-50% of total meat ingredients gave satisfactory results in color, texture and palatability, comparable to regular products.

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Manufacture of Spent Layer Chicken Meat Products by Natural Freeze-Drying during Winter (겨울철 자연 동결 건조에 의한 노계 육제품의 제조)

  • Lee, Sung-Ki;Kang, Sun-Moon;Lee, Ik-Sun;Seo, Dong-Kwan;Kwon, Il-Kyung;Pan, Jo-No;Kim, Hee-Ju;Ga, Cheon-Heung;Pak, Jae-In
    • Food Science of Animal Resources
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    • v.30 no.2
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    • pp.277-285
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    • 2010
  • The objective of this study was to manufacture spent layer chicken meat products by natural freeze-drying. The spent layers of chickens that were slaughtered at 80 wk were obtained from a local slaughter house and separated into two halves of carcasses. The samples were divided into the following groups: 1) control (non-curing), 2) curing, and 3) curing with 2% trehalose before drying. The cured meats were placed at $2^{\circ}C$ for 7 d and then transferred to a natural drying spot located in Injae City, Gangwondo, Korea. The experiment was conducted from January to March in 2008. The average temperature, RH, and wind speed were $-1.5^{\circ}C$, 63%, and 1.8 m/sec, respectively. The cured treatments showed higher pH, lower Aw and lower shear force value compared with the control. Based on the results of TBARS (2-thiobarbituric acid reactive substances) level and volatile basic nitrogen value, lipid oxidation and protein deterioration were inhibited in curing treatments during drying. Trehalose acted as a humectant because it maintained a lower water activity despite the relatively higher moisture content during drying. The polyunsaturated fatty acids content and sensory attributes were higher in cured treatments than in the control during drying. Most of the bacterial counts in the treated groups were lower by 2 Log CFU/g after 1 mon of drying, and Salmonella spp. and Listeria spp. were not found in any treatment. There was also no microbial safety problem associated with dried meat products. Based on the results of this experiment, dried meat products could be manufactured from precured spent layer chickens by natural freeze-drying during winter.

High Hydrostatic Pressure Sterilization of Vibrio parahaemolyticus and Escherichia coli in Raw Oyster (생굴 중 Vibrio parahaemolyticus와 Escherichia coli의 초고압 살균)

  • Park, Whan-Jun;Jwa, Mi-Kyung;Hyun, Sun-Hee;Lim, Sang-Bin;Song, Dae-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.7
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    • pp.935-939
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    • 2006
  • Raw oyster (Crassostrea gigas) was inoculated with Vibrio parahaemolyticus and Escherichia coli, treated with high hydrostatic pressure and evaluated for microbial counts. Cell death of V. parahaemolyticus (Vp) increased with the increase of applied pressure. Vp starting inoculum of $3.8{\times}10^5\;CFU/mL$ was totally eliminated after exposure to 200 MPa for 10 min at $22^{\circ}C$ Viable cell of Vp decreased with the increase in treatment time and dropped below the detection limit with treament of 25 min at $22^{\circ}C/150\;MPa$. The number of Vp by treatment of $0^{\circ}C$ and $10^{\circ}C$ for 20 and 25 mon at 100 MPa, respectively. For E. coli, there was an initial lag up to 250 MPa gollowed by a rapid decline. Treatment at 325 MPa/$22^{\circ}C$ for 15 min caused 5-log reduction, while that at 375 MPa resulted in total reduction of starting inoculum of $4.0{\times}10^7\;CFU/mL$. Lower treatment temperature showed higher killing effect of E. coli at the same treatment pressure and time. Viable cell of E. coli decreased with the increase in treatment time, and 4-log reduction was achieved with treatment of 5 min at $10^{\circ}C$/350 MPa and then total reduction was achieved after treatment of 15 mon. Higher pressure, lower temperature and longer time were more effective in sterilizing V. parahaemolyticus and E. coli.

Prevalence of Pathogenic Bacteria in Livestock Manure Compost and Organic Fertilizer (가축분퇴비와 유기질비료에서 병원성박테리아의 분포도 분석)

  • Jung, Kyu-Seok;Heu, Sung-Gi;Roh, Eun-Jung;Lee, Dong-Hwan;Yun, Jong-Chul;Kim, Kye-Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.5
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    • pp.824-829
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    • 2011
  • In recent years, there has been an increasing public concern about fecal contamination of water, air and agricultural produce by pathogens residing in organic fertilizers such as manure, compost and agricultural by-products. Efforts are now being made to control or eliminate the pathogen populations at on-farm level. Development of efficient on-farm strategies to mitigate the potential risk posed by the pathogens requires data about how the pathogens prevail in livestock manure composts and organic fertilizers. Microbiological analysis of livestock manure composts and organic fertilizers obtained from 32 and 28 companies, respectively, were conducted to determine the total aerobic bacteria count, coliforms, Escherichia coli count and the prevalence of Staphylococcus aureus, Bacillus cereus, Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes, and Cronobacter sakazakii. The total aerobic bacteria counts in the livestock manure composts and organic fertilizers were in the range of 7 to $9log\;CFU\;g^{-1}$ and 4 to $6log\;CFU\;g^{-1}$, respectively. In the livestock manure composts, coliforms and E. coli were detected in samples obtained from 4 and 2 companies, respectively, in the range of 2 to $5log\;CFU\;g^{-1}$ and $2log\;CFU\;g^{-1}$. In the organic fertilizers, coliforms and E. coli were detected in samples obtained from 4 and 1 companies, respectively, in the range of 1 to $3log\;CFU\;g^{-1}$ and $2log\;CFU\;g^{-1}$. In 3 out 32 compost samples, B. cereus was detected, while other pathogens were not detected. In 28 organic fertilizers, no pathogens were detected. The complete composting process can result in the elimination of pathogens in livestock manure compost and organic fertilizer. The results of this study could help to formulate microbiological guidelines for the use of compost in environmental-friendly agriculture. This research provides information regarding microbiological quality of livestock manure compost and organic fertilizer.

Shelf Life Extension of Wasabi Paste Products by Addition of Citric Acid (구연산 첨가에 의한 와사비 페이스트 제품의 저장성 향상)

  • Jeong, Eun-Jeong;Lee, Hyo-Kyung;Kim, Yong-Suk
    • Journal of Food Hygiene and Safety
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    • v.34 no.4
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    • pp.354-360
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    • 2019
  • In order to extend the shelf life of Wasabi paste, the effects of citric acid were confirmed at $35^{\circ}C$ for 28 days. Citric acid-treated groups contained citric acid in amounts of 0.05, 0.10, 0.17, 0.30, and 0.40%, respectively. Quality characteristics of Wasabi pastes were determined in pH, titratable acidity, soluble solid content, color values, microbial analysis (aerobic bacteria, yeast), gas production, and content of allyl isothiocyanate. The pH and titratable acidities of Wasabi pastes added with citric acid were indicated as 4.03-5.19 and 4.23-4.82%, respectively. Soluble solid content was significantly different according to concentrations of citric acid. L values showed the highest at $50.05{\pm}0.46$. a and b values were increased during the storage period. Total aerobic bacteria and yeast counts of Wasabi pastes were decreased in a dose-dependent manner. Gas production from Wasabi pastes showed at 19.55-19.80 mL/tube after 28 days of storage. The addition of citric acid (0.3% or more) to the Wasabi paste resulted in increased storage stability.

Microbiological Safety Evaluation on Ice Cream and Ice Pop Products (빙과류의 품목별 제품의 미생물학적 안전성 평가)

  • Yu, Jeong-Wan;Kim, So-Hyun;Hong, Dong-Lee;Kim, Hyeon-Jae;Jeong, Eun-Joo;Lee, Jae-Hwa;Yang, Ji-Young;Lee, Yang-Bong
    • Journal of Food Hygiene and Safety
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    • v.34 no.4
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    • pp.367-373
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    • 2019
  • In order to evaluate the microbiological safety of ice cream products, the total viable bacterial counts were measured in 6 kinds of ice pops, 5 kinds of non-milk fat ice cream, and 5 kinds of milk fat ice cream, sold in local markets. In addition, E. coli, S. aureus, B. cereus, and L. monocytogenes were artificially inoculated in three types of ice cream products and stored at $-5^{\circ}C$, $-10^{\circ}C$, and $-18^{\circ}C$, respectively, and after inoculation, viable cells were measured periodically. As a result of the total viable count, about 1~2 log CFU/mL was detected in 16 kinds of ice cream products. As a result of inoculation with microorganisms at various temperatures, the number of viable cells decreased as the storage period became longer, and the higher the storage temperature, the faster the microorganisms died. Especially, the microorganisms were killed faster in the ice pop products than in the other ice cream products, and the microorganisms were killed relatively slower in the milk ice cream. L. monocytogenes and S. aureus were relatively stable in frozen conditions compared to other microorganisms. The microbial contamination of commercial ice cream was lower than the allowable standard of the Korean Food Code. Microorganisms did not proliferate when the microorganism was inoculated at freezing temperature. Therefore, it is expected that the microbiological safety of frozen foods will be ensured if the sanitary control and disinfection of raw materials are thoroughly carried out during the production of frozen confections and the temperature control during distribution and storage is well maintained.

Characteristics and anti-obesity effect of fermented products of coffee wine (커피발효물의 발효특성 및 항비만 효과)

  • So Hyun Park;Hyeon Hwa Oh;Do Youn Jeong;Young-Soo Kim
    • Food Science and Preservation
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    • v.30 no.4
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    • pp.703-715
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    • 2023
  • This study was conducted to investigate the fermentation characteristics and anti-obesity effects of acetic acid fermentation products of coffee wine. The live cell counts, soluble solids, pH and total acidity of the acetic acid unfermented coffee wine (AUFCW; day 0, before fermentation) were 6.35 log CFU/mL, 8.10 °Brix, 3.88, and 1.29%, respectively, while the acetic acid fermented coffee wine (AFCW; day 15, after fermentation) were 4.40 log CFU/mL, 8.57 °Brix, 3.07, and 7.45%, respectively. Pancreatic lipase inhibitory activity tended to increase as the acetic acid fermentation period increased. The anti-obesity effects of AFCW on 3T3-L1 cells, which was induced by MDI, were evaluated based on the lipid accumulation rate, leptin expression, and fat production-related gene expression (PPAR-γ and SREBP-1c) at the mRNA level. In the case of AFCW, the lipid accumulation rate and leptin expression were decreased to 69.37% and 50.20% at a concentration of 200 ㎍/mL, respectively, and the expression levels of PPAR-γ and SREBP-1c at the mRNA level were decreased to 79.89% and 48.81%, respectively. These results indicate that anti-obesity effect of acetic acid fermentation products could be increased by acetic acid fermentation of coffee wine.