• 한국환경보건학회지
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• 제41권2호
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• pp.82-89
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• 2015

Objectives: This study was performed to investigate the effect of cooking time on the internal temperature and color of cutlets and the reduction of indicator organisms in cutlets by cooking. Methods: Three kinds of commercially packed frozen cutlets (pork, chicken and fish cutlets), were purchased from local markets. The cutlets were cooked in a frying pan at $180^{\circ}C$ for four minutes. Internal temperature was measured with a food thermometer. Color was measured using a Hunter spectrocolorimeter. Aerobic colony counts, coliforms, and Escherichia coli were determined according to the Food Code of Korea. Results: The internal cooked temperature of every cutlet reached over $74^{\circ}C$, the temperature considered safe, after three minutes, while external temperature reached this level in two minutes (p < 0.001). The instrumental color value as lightness (L) in the cooked cutlets significantly changed (p < 0.001) after one minute. The level of aerobic colony counts of fresh cutlets was under the specification and was reduced to one tenth its level in the cooked cutlets. Coliforms and E. coli were not detected in all samples. The internal temperature of the cutlets was significantly affected by cooking time and weight (p < 0.001). The interaction effect of time and weight was also significant (p < 0.001), and time was the more influential factor. Conclusion: The results of this study indicate that the sampled cutlets should be cooked for a minimum of three minutes or more in order to ensure food safety. The results also indicate that if consumers cease cooking based on external temperature or color, there will be a risk of inadequate cooking.

• 한국환경과학회지
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• 제10권3호
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• pp.239-245
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• 2001

This research was performed to investigate the dynamics of microbial community by RBC (Rotating Biological Contactor) using Rhodococcus sp. EL-GT and activated sludge. Cell counts revealed by DAPI were compared with culturable bacterial counts from nutrient agar. Colony counts on nutrient agar gave values 20~25% and 1~15% of cell counts (DAPI). The cell counts for the dynamics of bacterial community were determined by combination of in situ hybridization with fluorescently-labelled oligonyucleotide probes and epifluorescence microscopy. Around 90~80% of total cells visualized DAPI were also detected by the bacteria probe EUB 338. For both reactors proteobacteria belonging to the gamma subclass were dominant in the first stage (1 and 2 stage) and proteobacteria belonging to the gamma subclass were dominant in the last stage (3 and 4 stage).

• 한국식품조리과학회지
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• 제25권1호
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• pp.45-54
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• 2009

Contamination levels of aerobic colony counts, coliforms and pathogenic bacteria were tested in fried rice dishes to monitor quality for risk management. The prevalence of Bacillus cereus in dishes from 8 Chinese-style restaurants and 2 institutional foodservices was 10%, and the bacteria's contamination levels was 3.47 log CFU/g. Echerichia coli, Staphylococcus aureus, and Salmonella were not detected in any of the 10 samples. However, for their aerobic colony counts and numbers of isolated coliforms, the samples were 30% and 70% over the microbial criteria, respectively, for ready-to-eat foods presented in the Korean Food Code. This suggests that fried rice dishes, although cooked with oil at high temperature, require special care. For the prediction of the growth curve of B. cereus spp. in the fried rice samples, an experiment design of 3 storage temperatures ($7^{\circ}C$, $35^{\circ}C$, $57^{\circ}C$) x 5 storage times (0 h, 2 h, 4 h, 6 h, 24 h) was applied. The sample exposed to $35^{\circ}C$ showed no B. cereus spp. at 0 h; however, there was a tendency of slow growth (1.0 log CFU/g) after 4 hours of storage and then faster growth at 6 h (3.7 log CFU/g) and 12 h (4.7 log CFU/g), showing a growth rate of 0.56 log CFU/g/hr. These results indicate that fried rice, despite being heat-treated, can become heavily contaminated with B. cereus spp. when held over 2 hours at room temperature. However, the samples stored at $7^{\circ}C$ and $57^{\circ}C$ over 24 hours were not contaminated with B. cereus. Based on these results, management guidelines for controlling B. cereus are suggested.

• 대한영양사협회학술지
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• 제25권1호
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• pp.1-16
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• 2019

This study examined the microbiological quality of daycare center meals. Six menu items from five daycare centers in Daegu included uncooked processed foods (seasoned cucumber and lettuce salad), post-preparation after cooking processed foods (rolled omelet and seasoned soybean sprout), and cooking processed foods (panbroiled beef with oyster sauce and seasoned pork roast). Microbiological analyses were performed for the aerobic plate counts (APC), coliforms, and Escherichia coli. The analyses were conducted in July and November 2017. The mean APC and coliform count of seasoned cucumber decreased significantly from 4.71 log colony forming units (CFU)/g and 2.50 log CFU/g in July to 4.07 log CFU/g and 1.78 log CFU/g in November, respectively (P<0.01 and P<0.001). The APC of panbroiled beef with oyster sauce and seasoned pork roast were significantly lower in July (1.84 and 1.79 log CFU/g) than in November (2.41 and 2.28 log CFU/g) (P<0.001). The coliform counts of panbroiled beef with oyster sauce and seasoned pork roast were significantly greater in November (2.11 and 1.62 log CFU/g) (P<0.001). E. coli was not detected. Among the foods prepared using the three preparation processes, the post-preparation after cooking processed foods had the lowest microbial quality. The APC and coliform counts of cooking processed foods were satisfactory in July, with an acceptable rating for pan-broiled beef with oyster sauce in November. Time-temperature control and the prevention of cross-contamination are essential during meal production for food safety, regardless of the season.

• 한국초지조사료학회지
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• 제42권2호
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• pp.96-102
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• 2022

본 연구에서는 미생물 첨가제와 사일로 밀도가 총체벼 곤포 사일리지의 영양소 함량, 발효특성 및 호기적 안전성에 미치는 영향을 규명하고자 수행하였다. 미생물 첨가와 사일로 밀도는 사일리지의 영양소 함량에 영향을 미치지 않았다. 하지만, INO 시험구에서 lactate 함량, lactate와 acetate 비율 및 LAB는 감소하였고, propionate 함량, yeast 및 호기적 안전성은 증가하였다. 사일로 밀도는 pH와 lactate 함량에 영향을 미쳤으나, 처리 구간 차이는 매우 적었다. 이상의 결과에서, L. brevis 5M2와 L. buchneri 6M1을 포함한 혼합형 LAB 첨가제 사용은 총체벼 곤포 사일리지의 호기적 안전성 개선에 유리하며, 사일로 밀도는 베일 압력이 430~770 kgf/cm²일 때 정상적인 사일리지 발효가 일어나는 것으로 확인되었다.

• 대한영양사협회학술지
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• 제19권3호
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• pp.236-252
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• 2013

The purpose of this study was to assess the microbiological quality of home-delivered meals during production and delivery for children from low-income families. Production flows from a facility in Seoul that provides home-delivered meals were analyzed and the time-temperature of the food was measured. Microbiological assessment was performed for the production environment, personal hygiene, and food samples at each production and delivery step based on the process approach. It took 2 hours or longer from completion of production to meal delivery. An aerobic colony count (ACC) and coliform were not detected at knives, cutting boards, and dish towels. However, ACC (at pre-preparation, preparation, and packing areas) and coliform (at the preparation area) were detected on the hands and gloves of employees. Air-borne bacterial counts varied according to day and preparation area (ND~6 CFU/plate/15 min). Food temperatures, on the completion of production and meal delivery, fell into temperature danger zones. ACC and coliform counts of raw ingredients did not decrease after pre-preparation (washing and sanitizing) for menus involving food preparation with no cook step. ACC decreased after cooking step for menus of food preparation with cook step, but the ACC of the stir-fried and seasoned dried filefish fillet on the completion of cooking was too numerous to count due to improper heating. The ACC of seasoned young Chinese cabbages (a menu with complex food preparation) increased during delivery (from 2.5 log CFU/ml to 5.0 log CFU/ml). This qualitative assessment of foodborne pathogens revealed that B. cereus was detected in vegetable and meat product menus. These results suggest time-temperature control is necessary during production and delivery and management guidelines during production of home-delivered meals are provided for safe production.

• 한국식품위생안전성학회지
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• 제23권3호
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• pp.257-263
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• 2008

본 연구는 식품의약품안전청에서 2005년도 생식류에 대한 미생물 기준이 제정됨으로 관련 미생물에 대한 기준규격이 적절히 실행되고 있는지를 파악하기위하여 모니터링을 실시하였다. 생식류의 미생물적 기준규격은 E. coi 음성, B.cereus 1 g당 1,000 이하이며, Cl. perfringens 1 g당 100 이하로 규정하고 있다. 따라서 시중에 유통 중인 생식류를 수거하여 E. coli, B. cereus, Cl. perfringens 및 세균수에 대한 모니터링을 진행하였다. E. coli는 99건 모두 음성으로 분석되었으며, B. cereus의 경우 56건(57%)에서는 음성이며, 42건(42%)에서 최소 100 cfu/g부터 최대 900 cfu/g으로 나타났다. 그리고 1건에서 기준규격을 초과하는 3,500 cfu/g이 검출되었다. Cl. perfringens의 분석결과는 98건(99%)에서는 음성으로 분석되었으며, 1건(1%)에서 10 cfu/g로 나타났고 세균수의 경우 검체별로 최소 10 cfu/g부터 최대 $5.3{\times}10^7cfu/g$으로 나타났다. 위의 결과로부터 특정제품을 제외하면 식중독 미생물의 경우는 비교적 위생적으로 처리되고 있음을 알 수 있었으나 B. cereus와 세균수의 경우 좀 더 위생적인 관리가 필요한 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권2호
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• pp.218-221
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• 2002

Whole forage sorghum (saccharatum) cultivar FS5 was harvested at the soft dough ($303{\pm}9g\;kg^{-1}$ DM) stage of maturity. The sorghum was chopped into approximately 20 mm pieces and ensiled under laboratory conditions in 1.5 L Weck glass jars. At ensiling, it was treated with two commercial silage inoculants: Pioneer 1188 (Inoculant A) and Eco-corn (Inoculant B). The inoculant A and B was applied at ca $2{\times}10^5$ or $2{\times}10^4$ colony forming units $g^{-1}$ DM., respectively. Silage with no additives served as a control. Three jars per treatment were opened on days 2, 4, 8, 15 and 60 post-ensiling to study fermentation dynamics. After 60 days of ensiling the silages were analyzed and subjected to an aerobic stability test lasting 5 days. Results showed that both inoculants caused a more rapid rate of pH decrease and a higher amount of lactic acid production. All the silages were well preserved and were stable upon exposure to air. Inoculants did not influence (p>0.05) the ash and total N contents, but tended to reduce acetic acid (p<0.05), butyric acid (p<0.01) and propionic acid (p<0.01) contents, and to increase the lactic acid content (p<0.01). The lower DM content of silages treated with Inoculant A agrees with the greater gas loss resulting from the DM loss, which was in good agreement with the higher yeast counts upon aerobic exposure. Silage treated with inoculant B had the highest DM (p<0.05) and lactic acid contents (p<0.01), and the lowest acetic acid content (p<0.05), which agrees with the rapid reduction of pH and smaller gas loss. Inoculant B reduced the ADF (p<0.01), ADL and NDF (p<0.05) contents, which also indicates smaller losses of organic soluble material. The control silages contained the highest levels of volatile fatty acids but no lactic acid, indicating secondary fermentation. It was concluded that both inoculants may improve the fermentation process, since silages from all treatments were stable upon aerobic exposure, noadvantage could be attributed to any of the inoculants used.

• 한국식품과학회지
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• 제32권6호
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• pp.1341-1349
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• 2000

젓갈 미생물 계수용 배지의 소금농도를 결정하기 위한 실험에서는 NaCl을 5% 첨가한 배지에서 가장 많은 수의 미생물이 계수되었고, 시료를 보존하기 위한 동결보호제는 glycerol 15%를 사용하였을 때 $-170^{\circ}C$에서 30일 보존 후 총균수는 75.5%, 젖산균수는 61.3%로 가장 높은 생존율을 나타내었다. 조개젓의 숙성과정 중 pH는 초기 6.8에서 5.0으로 낮아졌고, 숙성 후 단백질 함량은 조개젓은 10%, 멸치액젓은 $6{\sim}7%$이었다. 조개젓의 미생물수는 멸치액젓의 미생물수보다 많았고, 조개젓의 경우는 숙성기간에 따라 미생물수가 증가했다가 감소하는 경향을 보여주었으나 멸치액젓은 서서히 감소하는 경향을 보여주었다. 조개젓의 경우 숙성 4주까지 그램 양성, 카탈라아제 음성 세균들의 비율이 크게 증가하는 전형적인 젖산 발효 형태를 보여주었다. 젓갈을 $-170^{\circ}C$의 액체질소 탱크에서 2년간 보존 후 미생물수는 전체적으로 90% 이상 사멸하였고, 균총 변화를 보면 조개젓의 경우에는 그램 음성 세균과 간균의 생존율이 더 높았으나 거제 멸치액젓의 경우는 간균의 비율이 구균에 비해 감소하였다. 두 가지 젓갈에서 모두 효모의 비율은 크게 떨어졌다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1252-1264
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• 2020

Objective: To effectively utilize crop by-product resources to address the shortage of animal feed during the dry season in Africa, the community of natural lactic acid bacteria (LAB) of corn stover and sugarcane tops and fermentation characteristics of silage were studied in Mozambique. Methods: Corn stover and sugarcane tops were obtained from agricultural field in Mozambique. Silage was prepared with LAB inoculant and cellulase enzyme and their fermentation quality and microbial population were analyzed. Results: Aerobic bacteria were the dominant population with 10⁷ colony-forming unit/g of fresh matter in both crops prior to ensiling, while 10⁴ to 10⁷ LAB became the dominant bacteria during ensiling. Lactobacillus plantarum was more than 76.30% of total isolates which dominated silage fermentation in the LAB-treated sugarcane top silages or all corn stover silages. Fresh corn stover and sugarcane tops contain 65.05% to 76.10% neutral detergent fiber (NDF) and 6.52% to 6.77% crude protein (CP) on a dry matter basis, and these nutrients did not change greatly during ensiling. Corn stover exhibits higher LAB counts and water-soluble carbohydrates content than sugarcane top, which are naturally suited for ensiling. Meanwhile, sugarcane tops require LAB or cellulase additives for high quality of silage making. Conclusion: This study confirms that both crop by-products contain certain nutrients of CP and NDF that could be well-preserved in silage, and that they are potential roughage resources that could cover livestock feed shortages during the dry season in Africa.