• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.380-384
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• 2002

For the screening of gamma-irradiated grains, domestic rice, glutinous rice, barley, and wheat were irradiated with 0.1, 0.3, 0.5, 0.7, and 1.0 kGy and screened using the DEFT/APC (Direct Epifluorescent Filter Technique/Aerobic Plate Count) method. The log DEFT/APT units increased with the dose increment in all samples, whereas the log APC unit decreased gradually. For rice, barley, and wheat, unirradiated and irradiated samples with below 0.3 kGy had 2.0 or lower logarithmic units, whereas those with 0.5 kGy or higher had 2.0 or higher logarithmic units. For glutinous rice, the sample irradiated with 0.5 kGy showed 1.92 logarithmic unit and those with 0.7 kGy or higher had 2.0 or higher logarithmic units. These results suggest that if the grains show 2.0 or higher logarithmic units, they could be assumed to have been irradiated at a dose level of at least 0.5 kGy. In conclusion, grains could be easily screened through the DEFT/APC method.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.232-235
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• 2004

Since ready-to-use (RTU) products are not fully cooked, the shelf-life of the product is comparably short and the products are easily spoiled when contaminated with food-borne pathogens. Low-dose gamma irradiation of 0.5, 1, or 2 kGy effectively reduced the total aerobic bacterial counts in 2 Korean manufactured RTU products by 1.63 to 2.95 log CFU/g during cold storage. Irradiation at 2 kGy reduced the psychrotrophic bacterial counts in most of the samples to below the limit of detection (< log CFU/g). Irradiation at 0.5 kGy completely eliminated Escherichia coli from the commercial RTU samples.

• Journal of the FoodService Safety
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• v.1 no.1
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• pp.19-25
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• 2020

A reduced salt, dry-type bulgogi bibimbap with AF-343 was prepared, and the acceptance, antioxidant antimicrobiological safety were investigated. The acceptance of the reduced salt and the AF-343 added sample, RW, showed the highest value of 5.37 among the samples, but it did not differ significantly from the other samples of the standard sample group. The acceptances of the appearance, aroma, texture, and overall acceptance were not significantly different in all samples (p>0.05). In the DPPH radical scavenging activity, the values of SW and RW with the AF-343 were 15.05 and 14.77, respectively, which were significantly higher than the 9.57 and 10.42 obtained for SWO and RWO without AF-343, respectively (p<0.05). Pathogenic microorganisms tests that were either negative or not detected in any of the samples representing hygiene safety were met in the dried bibimbap against Escherichia coli, pathogenic microorganisms, and general bacteriological tests. The aerobic plate counts were 30.0 CFU/g, indicating that the dry type salt-reduced bibimbap containing AF-343 was within the safety range that meets the safety standards of microorganisms in the food code for commercialization. Therefore, high-quality dry-type reduced salt bibimbap with AF-343 is helpful for antioxidant action and effective for skin moisturizing and can be produced without affecting the taste and palatability.

• Food Science of Animal Resources
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• v.43 no.3
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• pp.441-453
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• 2023

The objective of this study was to investigate the physicochemical and microbiological characteristics of round of Hanwoo by vacuum packaging film materials, polyvinylidene chloride (PVDC) and ethylene vinyl alcohol (EVOH). The packaged beef samples were stored in refrigerated conditions (2±1℃) for 12 weeks. Physicochemical analysis with pH, surface color, thiobarbituric acid reactive substances (TBARS) values, and volatile basic nitrogen (VBN) values and microbiological analysis with aerobic plate count (APC) and metagenomic analysis of packaged beef samples were performed. The pH and surface color did not change substantially during the 12 weeks and EVOH-packaged beef tended to be lower than those of PVDC-packaged beef. PVDC- and EVOH-packaged samples showed low TBARS and VBN values below standard limits. APC did not exceed 7 Log CFU/g for both samples during storage. In metagenomic analysis, Firmicutes and Lactobacillaceae were dominant phylum and family of the PVDC- and EVOH-packaged beef. In both packaged samples, Dellaglioa algida was the dominant species during storage, with the notable difference being the presence of Lactococcus piscium. Therefore, this study provided the information on the quality of vacuum-packaged beef according to different vacuum films for long-term refrigerated storage.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.80-86
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• 2007

This experiment was conducted to investigate the changes of pork meat quality characteristics exposed to ozone gas for 5, 10, and 15 min and then vacuum packaged during storage for 0, 5, 10, 15, and 20 day at $4^{\circ}C$. The ozone gas exposed groups of pork loin cuts (OZM) had slightly higher pH value compared to the control at day 0 and 5 (p<0.01). The 15 min exposure of ozone gas groups showed significantly (p<0.01) higher TBARS value than that of control at the day 15 and 20. However, there was no significant difference in all groups at day 0,5, and 10. The CIE $L^*$ and $b^*$ values of OZM showed no significant difference between control and ozone gas treated groups during storage. The loin cut color of ozone gas exposure for 15 min had significantly lower CIE $a^*$ values than the other groups at day 0,5, and 15 (p<0.01). The aerobic plate count and coliform bacteria count of pork loin cuts exposed ozone gas significantly (p<0.01) was reduced at day 0 by about $0.45-1.04\;log_{10}CFU/g$ and $0.26-0.30\;log_{10}CFU/g$, respectively. As ozone gas exposure time extended, the aerobic plate count and coliform bacteria count of OZM were increased at day 0, 5, and 10 (p<0.01). However, there were no significant differences observed among groups at day 20 in the counts of aerobic and coliform bacteria. In conclusion, the meat cuts exposed to ozone gas for 5 and 10 min before packing may be a reasonable packing method regarding the effects of ozone level on meat oxidation, color change and microbial reduction.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1253-1260
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• 2018

Pig small intestine not only is used as food but also for sausage casings production in many countries worldwide. However, it is well recognized that the small intestine is important source of spoilage and pathogenic bacteria. The present study aimed at investigating the effects of different washing and packaging methods on the changes of microbial levels and physicochemical characteristics of pig small intestine. After collecting and trimming off of visible fats, the pig small intestine samples were treated with; (i) different packaging methods: aerobic packaging (AP), skin packaging (SP), and vacuum packaging (VP); and (ii) washing with different concentrations of acetic acid. The treated samples were then stored at $4^{\circ}C$ for 1, 4, 7, and 10 d. At 1-d storage, higher pH value was found in the AP-treated samples, however, after 7 to 10 days the samples treated with SP had higher values compared to the ones treated with AP and VP (p<0.05). Thiobarbituric acid reactive substances values were higher in the AP-treated samples than those of the SP- and VP- treated samples at 7-d storage (p<0.05). At $10^{th}$ d, total plate counts (TPC) were higher in the control than in the acetic acid-washed samples (p<0.05). Additionally, the TPC was lower in the SP- and VP-treated samples than the AP-treated samples at 7-d storage (p<0.05). These obtained results suggest that the applications of washing with acetic acid solution and/or SP and VP methods could be an effective way to extend the shelf-life of pig small intestine during cold distribution.

• Journal of Animal Science and Technology
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• v.47 no.4
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• pp.679-690
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• 2005

This study was carried out to evaluate the quality characteristics of aerobic packed pork during storage after fermentation with soy sauce, red pepper and soybean paste seasonings. The ham of pork were cut to cube($7{\time}10{\time}2$cm) and Korea traditional seasonings such as soy sauce(T1), red pepper paste(T2), soybean paste(T3) were seasoned by the proportions of meat to seasonings(1:1), respectively. The seasoned sample were fermented by fill into plastic box at $1{\pm}1^{\circ}C$ for 10 days. And then, the fermented meat from each pack was aerobic packed and stored at $1{\pm}1^{\circ}C$ for up to 28 days. The pH of T1 were significantly(P<0.05) lower compared to T2 and T3 at 1 day of storage, but were significantly(P<0.05) higher at 14 and 28 days of storage. The water-holding capacity of T1were significantly(P<0.05) higher compared to T2 and T3 at 1 and 28 days of storage. The shear force of T3 were significantly(P<0.05) lower compared to T1 during storage. The surface meat L* values of T3 were significantly(P<0.05) higher than those of T1 and T2, but a* and b* values of T2 were significantly(P<0.05) higher. The volatile basic nitrogen(VBN) of T3 were significantly(P<0.05) lower compared to T2 at 1 and 14 days of storage, but T1 were significantly(P<0.05) lower at 28 days of storage. The thiobarbituric acid reactive substances(TBARS) of T3 were significantly(P<0.05) lower compared to T1 and T2. The total plate counts of T1 were significantly(P<0.05) lower compared to T2 and T3 at 1 day of storage, but T2 were significantly(P<0.05) lower at 14 and 28 days of storage. The Escherichia coli of T1 and T3 were significantly(P<0.05) lower compared to T2 at 1 day of storage. The Lactobacilli spp. of T2 were significantly(P<0.05) lower compared to T1 and T3.

• Journal of Life Science
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• v.19 no.3
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• pp.349-355
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• 2009

Metabolic fingerprinting of microbial communities was investigated with Biolog GN2 plates using samples of biofilm and aeration tanks from an RABC (rotating activated Bacillus contactor) system - an advanced wastewater treatment system for the food wastewater of pig slaughterhouses. Aerobic and anaerobic results revealed the following four aspects. First, simple matching and pairs t-test of daily variation showed more defined qualitative and quantitative relatedness of active microbial communities than that of mere optical densities. Second, metabolic potentials were higher in biofilm than in aeration tanks (p<0.01), meaning higher activity of biofilm. Third, two aeration tanks showed the highest similarity (78%) and similar metabolic power (p=0.287). However, actively used carbon sources were different among samples, signifying change of active communities at each wastewater treatment step. Finally, aerobic and anaerobic metabolic fingerprinting patterns were different for the same samples representing activities of microaerophilic and/or anaerobic communities. These results suggest that daily variation and anaerobic incubation would help in the comparison of metabolic fingerprintings.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.873-883
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• 2008

In this study, we assessed consumers' recognition of frozen foods via a survey study, and monitored the contamination levels of total aerobic bacteria and Escherichia coli in imported and domestic frozen seafoods obtained from five whole sale markets in Seoul. A questionnaire used to assess the perception of frozen food safety and the attitude towards frozen food usage was developed and distributed to 350 adults. A total of 324 questionnaires were subjected to frequency analysis and a chi-square test, using SPSS for Windows. The results of our survey study demonstrated that 44.6% of the respondent consumed frozen processed foods two to three times per month, with dumplings being the most frequently purchased. 70.5% of the respondents selected "convenient cooking" as the principal reason for their frozen food purchases. 58% of the respondents believed that frozen processed food is not safe to eat as the result of food additives and changes in quality during the shelf life period. Consumers most profoundly preferred frozen seafood originating from America, and preferred that from China least profoundly (81.2%). Microbiological analyses demonstrated that the aerobic plate counts of frozen seafood, regardless of origin, fulfill the standard requirements except for one frozen clam (6.6 Log CFU/g), which was a heated-frozen domestic product. In addition, E. coli was isolated from frozen cooked mussels, frozen raw clams and squids, thus indicating that more strict hygienic regulation for frozen seafoods will be necessary to protect the consumer in both domestic and foreign markets.

• Journal of the Korean Society of Food Culture
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• v.22 no.3
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• pp.342-352
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• 2007

We investigated the intake trends of street foods for middle school, high school and colleges students through the survey study. In addition, the factors affecting the students' consumption of street foods and their perception toward hygiene status of street vendor were studied. The levels of total aerobic bacteria, coliform groups and enterobacteriaceae in Kimbab, eomuk, and eomuk-kukmul were counted using 3M petrifilms. More than ninety seven % of the respondents had experienced street foods. All the respondents ate street foods 1 to 5 times a month. Forty percent of the respondent stated that 'good taste' and 'time-saving convenience' were their reason for eating the street foods. Their favorite foods were ddokbokgi and various fried foods. All the students responded that frying oil, drinking water, and soy sauce as well as the street vendors' attire and their cooking tools in street vendor were unsanitary. Forty percent of the respondents ranked frying oil as the most unsanitary substance. Eighty percent of the respondents responded that an enforcement of hygiene should be imposed on the street foods vendor. There were significant differences (p<0.001) among the student's age in the opinion related to the reasons of eating street foods, hygiene enforcement, existence of street foods and interest of hygiene status of street foods. High correlation (p<0.05) between the frequency of street foods and snack intakes was shown, regardless of student's age. The result shows that those who eat snacks more than once a day tend to eat street foods more frequently. Aerobic plate counts in Kimbab in 5 different vendors exceeded 10$^5$/g and contamination levels of enterobacteriaceae or coliform in Kimbab exceeded more than 10$^3$/g, which did not satisfy the microbiological standards. In conclusion, although the respondents thought that the sanitation of street foods was poor, most of them want the street food vendor to be maintained with better hygiene condition. This indicated that the regulation for safe street foods should be enforced and educational information about the preparation and serving for safe street foods should be provided to street food vendor.