• Title/Summary/Keyword: microbiological stability

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Microbiological Stability Test of Biodisel (바이오디젤의 미생물 안정성 조사)

  • 박근형;정해영;채희정
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.4 no.4
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    • pp.387-390
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    • 2003
  • The microbiological stability was examined by detecting the growth of microorganisms in the closed bottles under anaerobic long-term storage at $25^{\circ}C$ and 35$^{\circ}C$. Microbial growth was examined by a microscope and total cell number on a plate medium was quantitatively measured. There was no observed microbial growth in biodiesel for 90 days.

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Production and Microbiological Characteristics of Fermented Sausages (발효소시지의 생산과 미생물적 특성)

  • Benno Kunz
    • Food Science of Animal Resources
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    • v.23 no.4
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    • pp.361-375
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    • 2003
  • In this study, significant factors influencing on the quality and stability of fermented sausage, such as materials, processing conditions, and microbiological characteristics as well as topography during ripening, were documented. Since most fermented sausages are not heated during manufacture or before consumption, a strict control of the growth of pathogens and the selection of favourable conditions that encourage the specific growth and development of desirable microflora are particularly important. With respect to microbiological safety, hurdles, i.e., preservations(nitrite), redox potential, competitive flora, acidity(pH), and water activity($a_{w}$) are matters of importance to prevent proliferation of bacterial pathogens. Today, for ensuring the safety and quality of the final product, the application of starter cultures in combination with the proper processing is subsequently used in practice. For improving the efficiency of microbiological utility in the production of fermented sausages, the understanding of their topography is essential. The documented different points must be taken into account when HACCP systems set up for the manufacture of fermented sausages. There are continuous researches concerning desirable improvements to sausage fermentation with health enhancing properties.

Effect of Electron Benm Irradiation on the Oxidative and Microbiological Stability of Ground Pork during Storage (전자선 조사가 분쇄 돈육의 저장 중 산화와 미생물적 안정성에 미치는 영향)

  • Koh, Kwang-Hwan;Whang, Key
    • Food Science of Animal Resources
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    • v.22 no.4
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    • pp.316-321
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    • 2002
  • Fresh ground pork was irradiated with the electron beam, and the microbiological and oxidative stability of ground pork was examined during refrigerated and frozen storage. During both storage, with the increase in the irradiation dose from 0 to 3.0 kGy, the inhibition effect of the growth of the total aerobic bacteria and the mesophiles also increased. Psychrotrophic bacteria were not detected at all in the whole experiment. On the other hand, electron beam irradiation promoted the oxidative rancidity of ground pork during refrigerated and frozen storage. The catalytic effect of oxidation was more pronounced with the electron beam dose of 3.0 than that of 1.5 kGy. As a result, the control of lipid oxidation must be achieved to fully utilize the sterilization effect of electron beam in the ground pork.

Expression and Application of Heterologous Genes in Saccharomyces cerevisiae

  • Nam Soo-Wan
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2003.05a
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    • pp.122-124
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    • 2003
  • Cyclodextrin glucanotransferase (CGTase) and endoxylanase genes of Bacillus sp. were subcloned down-stream of yeast ADH1 promoter and expressed in S. cerevisiae. Most of the CGTase and endoxylanase expressed were detected in the extracellular medium with activity of 0.6 and 7-8 unit/ml, respectively. The recombinant enzymes were secreted as N-linked-glycosylated forms, resulting an enhanced thermal stability. CGTase predominantly produced $\alpha-cyclodextrin$ from starch and endoxylanase produced xylobiose and xylotriose from xylan.

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Microbiological and Oxidative Stability of Low Fat Ground Beef during Refrigeration (취반 재고미를 첨가하여 제조한 저지방 분쇄우육의 냉중중 안정성)

  • 김혁일
    • Food Science of Animal Resources
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    • v.18 no.4
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    • pp.301-306
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    • 1998
  • Four low fat ground beef groups containing 10% fat plus 0, 5, 10 and 20% additional cooked lod rice and a control ground beef containing 30% fat were prepared and the analysis for microbiological and oxidative stability were conducted. During 6 days of storage at 4$^{\circ}C$ microbial analysis including total plate count and coliform groups were performed and 2-thiobarbituric acid reactive substance (TBARS) absorbances were measured. The growth rate of total aerobic bacteria and coliform groups tended to increase with the increase in fat content and the amount of added cooked lod rice. Development of oxidative rancidity were not significantly different between 10 and 30% fat ground beef but among the 10% ground beef the rancidity development significantly(p<05) decreased with the in-crease in the amount of added cooked old rice. Low fat ground beef groups were not stable over 3 days during storage at 4$^{\circ}C$.

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The Microbiological and Sensorial Properties of frozen bibimbap namul during storage (저장기간에 따른 냉동 비빔밥 나물의 미생물학적, 관능적 특성)

  • 한영실;박지영
    • Korean journal of food and cookery science
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    • v.17 no.2
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    • pp.149-155
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    • 2001
  • Namul cooked with the standard recipe was examined by research of microbiological test for three months and sensory evaluation of frozen namul after reheating. When the namul was freezed storage, in the microbiological test namul began to change on the 40th day, but there was no problem about stability of storage until 3 months. The overall qualities of taste, flavor, color and texture were examined by sensory evaluation of frozen namul after reheating. The pH was seemed to change slowly, its color was changed on the 20th day from the beginning of storage. Radish root represented substantial difference in texture and overall quality on the 20th day. The off-flavor of immature pumpkin stated on the 25th day. Later 10days nettle tree mushroom began to be changed in its taste, texture, overall quality and appearance, then on the 25th day it was seemed to have low preference. But oak mushroom kept its quality good for 25 days. Oyster mushroom was changed in color, appearance and overall quality on the 20th day. Bracken had low preference in taste, texture and moisture on the 25th day. The color of spinach was changed on the 15th day, and its taste on the 20th day. Soybean sprout was changed in taste, texture and overall quality on the 15th day, and overall quality marked low preference on the 25th day Root of bell flower was changed on the 25th day(p<0.05).

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Bleeding Efficiency and Meat Oxidative Stability and Microbiological Quality of New Zealand White Rabbits Subjected to Halal Slaughter without Stunning and Gas Stun-killing

  • Nakyinsige, K.;Fatimah, A.B.;Aghwan, Z.A.;Zulkifli, I.;Goh, Y.M.;Sazili, A.Q.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.3
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    • pp.406-413
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    • 2014
  • A study was conducted to compare the effect of halal slaughter without stunning and gas stun killing followed by bleeding on residual blood content and storage stability of rabbit meat. Eighty male New Zealand white rabbits were divided into two groups of 40 animals each and subjected to either halal slaughter without stunning (HS) or gas stun-kill (GK). The volume of blood lost during exsanguination was measured. Residual blood was further quantified by determination of haemoglobin content in Longissimus lumborum (LL) muscle. Storage stability of the meat was evaluated by microbiological analysis and measuring lipid oxidation in terms of thiobarbituric acid reactive substances (TBARS). HS resulted in significantly higher blood loss than GK. HS had significantly lower residual haemoglobin in LL muscle compared to GK. Slaughter method had no effect on rabbit meat lipid oxidation at 0, 1, and 3 d postmortem. However, at 5 and 8 days of storage at $4^{\circ}C$, significant differences (p<0.05) were found, with meat from the GK group exhibiting significantly higher levels of MDA than that from HS. At day 3, greater growth of Pseudomonas aeroginosa and E. coli were observed in the GK group (p<0.05) with B. thermosphacta and total aerobic counts remained unaffected by slaughter method. At days 5 and 7 postmortem, bacterial counts for all tested microbes were affected by slaughter method, with GK exhibiting significantly higher growth than HS. It can be concluded that slaughter method can affect keeping quality of rabbit meat, and HS may be a favourable option compared to GK due to high bleed out.

Effect of cumin essential oil usage on fermentation quality, aerobic stability and in vitro digetibility of alfalfa silage

  • Turan, Asli;Onenc, Sibel Soycan
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.8
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    • pp.1252-1258
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    • 2018
  • Objective: This study was carried out to determine the effects of cumin essential oil on the silage fermentation, aerobic stability and in vitro digestibility of alfalfa silages. Methods: Alfalfa was harvested at early bloom (5th cutting) stage in October and wilted for about 3 hours. The research was carried out at three groups which were the control group where no additive control was done (CON), cumin essential oil (CMN3) with 300 mg/kg and CMN5 with 500 mg/kg cumin essential oil addition. Alfalfa was ensiled in plastic bags. The packages were stored at $8^{\circ}C{\pm}2^{\circ}C$ under laboratory conditions. All groups were sampled for physical, chemical and microbiological analysis 120th day after ensiling. At the end of the ensiling period, all silages were subjected to an aerobic stability test for 7 days. In addition, enzimatic solubility of organic matter (ESOM), metabolizable energy (ME), and relative feed value (RFV) of these silages were determined. Results: pH level decreased in the cumin groups compared to CON (p<0.05), thus inhibiting proteolytic enzymes from breaking down proteins into ammonia. In addition, it increased ESOM amount, and concordantly provided an increase of ME contents. Similarly, dry matter intake and RFV ratio increased. After opening the silage, it kept its aerobic stability for three days. Conclusion: Cumin essential oil improved fermentation, and affected chemical and microbiological characteristics of silages. Especially the addition of 300 mg/kg cumin provided cell wall fractionation through stimulating the activities of enzymes responsible. It also increased the number and activity of lactic acid bacteria (LAB) through providing a development of LAB.

Studies on the Cellulolytic Enzymes of Stachybotrys atra(I) (Stachybotrys atra에서 추출한 섬유소 분해효소에 관한 연구. I)

  • 김은수;김영민;강영희;최태주
    • Korean Journal of Microbiology
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    • v.13 no.2
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    • pp.59-63
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    • 1975
  • When the enzyme preparations were at various temperatures for 1 hour, the thermal stability for the enzyme was maximum at $30{\circ}C.$ The optimum temperature for the enzyme activity was at $40{\circ}C.$ When the enzyme preparations were exposed to various pHs for 22 hours, the enzyme stability was maximum at pH 3.8, and it was decreased gradually as the pH rose up to 4.8, above which the stability was greatly restored. When the exposure period was extended from 22 to pH's 3.0 and 5.9, but the stability tended to rise at pH's below 3.0 and above 5.9. The optimum pH for the enzyme activity was obtained at 4.8.

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