We investigated the variations in the total bacterial counts (TBC) and coliform counts in a variety of Korean Hanwoo beef cuts (strip loin, rump, flank, shank, chuck and loin) stored at different temperatures after wrapping or vacuum packaging. TBC and coliform counts in all the cuts increased with an increase in the storage period. The initial microbial at baseline was higher in the chuck cut (2.0 log CFU/cm2) than in the other cuts (1.1~1.3 log CFU/cm2). Compared to wrapping, vacuum packaging effectively delayed spoilage. TBC exceeded 6 log CFU/cm2 at 2 and 4oC in 21 and 11 days for wrapped meats and in 50 and 32 days for vacuum-packaged meats, respectively. Regardless of the initial microbial count, the TBC of wrapped meats stored at 10 and 15oC exceeded 6 log CFU/cm2 in 4 and 3 days respectively, whereas that of the vacuumpackaged meats exceeded this level at these temperatures 6 and 5 days, respectively. Chuck cuts, with relatively high initial microbial levels, reached the spoilage point more quickly than other cuts under the same conditions. To sum up, vacuum packaging followed by storage and distribution at 2oC is the most effective approach for extending shelf life and maintaining quality.

본 연구에서는 신선편의식품을 구매한 뒤 집으로 귀가해서 냉장고에 보관하거나 섭취하는데 소요되는 시간과 그에 따른 신선편의식품 내.외부의 온도변화와 미생물학적 변화를 관찰하였다. 시판 중인 신선편의 식품에 대해 위생 지표세균인 일반세균, 대장균군 및 대장균, 병원성 미생물 인 B. cereus, S. aureus, Salmonella spp., L. monocytogenes를 분석하였다. 설문조사 결과 신선편의식품을 구매 후 귀가 또는 섭취에 소요되는 시간이 최대 3시간 소요되는 것으로 확인되어, 차량 트렁크 내에서 최대 3시간 동안 보관 한 결과 차량 트렁크 내부 최고 온도가 봄(3월) 19oC, 여 름(7월) 44oC, 가을(9월) 31.3oC, 겨울(2월) 17.6oC로 각각 확인되었으며, 차량 트렁크에서 보관한 신선편의식품의 품온은 최대 봄 18.5oC, 여름 42oC, 가을 29.2oC, 겨울 16.8oC 로 확인되었다. 차량 트렁크에 최대 3시간 보관한 신선편의식품의 일반세균수는 봄 3.41 log CFU/g, 여름 4.32 log CFU/g, 가을과 겨울은 각각 3.81 log CFU/g, 3.36 log CFU/g으로 확인되었다. 그 외의 대장균군 및 대장균, B. cereus, Salmonella spp., L. monocytogenes균은 검출되지 않았지만 S. aureus는 여름과 가을철에는 신선편의식품을 1시간만 차량에 보관하더라도 검출되었고, 봄과 겨울은 2시간 이상 차량 트렁크에 보관하였을 때 검출되었다. 이동 용기로 흔히 사용되는 종이박스와 스티로폼 박스 내부가 알루미늄필름으로 코팅된 종이 박스를 이용하여 얼음 첨가 여부에 따른 이동용기 온도변화 실험과 이동 중 S. aureus 의 증식여부를 확인한 결과 스티로폼 박스에서 내부 온도 변화가 가장 낮게 유지되었고, 시간 경과에 따른 미생물의 증식도 가장 적게 나타남을 확인할 수 있었다. 이상의 결과로 볼 때 신선편의식품 소비자들에게 구매 후 안전한 섭취를 위해 보관 온도나 시간에 대한 가이드라인과 이동용 기를 이용한 신선편의식품의 온도관리에 대한 정보를 제공 하여 식품의 안전성을 높이는 홍보가 필요할 것으로 판단된다.

This study was performed to evaluate changes of microbiological and hygienic quality characteristics of dry-cured ham during manufacturing process. The water activity(Aw) of dry-cured ham decreased significantly during the period(P<0.05). The salt contents increased from at 0 day to 60 days and decreased slightly at 60 days of post-curing(P<0.05). The contents increased after 120 days again. As the curing, drying and aging progressed, the VBN and TBA of dry-cured ham increased(P<0.05). The dry-cured ham samples showed significantly higher VBN at 120 and 180 days and higher TBA at 180 days. Regarding microbiological analysis, the total aerobic counts and lactic acid bacteria counts increased significantly during the stage(P<0.05). The total aerobic counts closely paralleled the lactic acid bacteria counts. In general, this research can be used as fundamental information for the mass production of a hygienic dry-cured ham.

As people seek a healthy, wealthy, and quality life more than before, interests in mineral water are picking up and the consumption continues to increase accordingly. In an experiment to examine changes in the water quality after mineral water on the market was kept indoor and outdoor for four weeks, there seemed to be no problem in external appearance. Water kept in an outdoor storage contained more odor-savor than water kept in an indoor storage. Odor was not detected in 90% of the sample, and savor not in 80% of it. As for the mechanism of odor-savor generation, the elution of chemical substances from a container may be taken into consideration. In general, odor and savor have turned out to be in close correlation to each other. The average number of bacteria in the sample mineral water was 200±10 CFU/mL, and such factors as area of storage and ozone post-treatment did not cause significant effects on the reproduction of common microbes. Hence, it is thought that strict regulations on a production process and reduction of the period of circulation will contribute to customers consumption rates.

To develop the low-temperature and long-term fermented kimchi, kimchi was prepared according to the recipe of a specific ratio of major and minor ingredients and adjusted its salinity to 3.7%. Prepared kimchi fermented at 15±1℃ for 24 hours and transferred and fermented in a refrigerator only used to make low-temperature and long-term fermented kimchi at -1±1℃ for 30 weeks. During 30 weeks of fermentation the changes in physicochemical and microbiological properties of low-temperature and long-term fermented kimchi were studied. The initial pH of 6.47 decrease gradually and dropped to pH 4.0 after 14 weeks of fermentation, and then it maintained at same level. Acidity increased to 0.49% on 2 weeks of fermentation and kept at 0.47 ~0.50% during 2 to 30 weeks fermentation. Salinity was slightly increased at early stage and started to decrease on 4 weeks of fermentation, and then it did not change. The change of reducing sugar content was closely related to the trend of pH change with a very high correlation coefficient(r =0.912). Lactic acid, citric acid, malic acid, succinic acid and acetic acid were major organic acids contained in low-temperature and long-term fermented kimchi. Vitamin C content decreased at initial stage of fermentation and then slightly increased up to the maximum of 22.3 mg% on 8weeks of fermentation. In color measurement, L value continued to increase during the fermentation and reached at the highest of 55.45 on 22 weeks of fermentation, and a and b values of 3.62 and 4.54 also increased to 31.26 and 37.32 on 30 weeks of fermentation, respectively. Total microbial count increased slowly from beginning and was the highest on 4 weeks of fermentation, and then began to decrease slowly. Count of Lactobacillus spp. was highest after 6weeks, but count of Lactobacillus spp. was highest on 2 weeks of fermentation, and then both showed a slow decrease. Yeast count wasn't increased until 4 weeks of fermentation and then increased rapidly to get the highest on 10 weeks of fermentation.

This study was carried out to changes in chemical and microbiological properties of spring waters in Tongyeoung area. In this paper, ninety spring water samples were collected from 9 station for 11 month to evaluated chemical and bacteriological water quality. Range and mean values of constituents of the samples are as followed; water temperature 5.2-25.8℃, 16.3℃, pH 6.0-7.2, 6.7, total residue 33.6-210 mg/1, 90.6 mg/1, turbidity 0.35-5.48, 1.45NTU, KMnO4 consumed 0.51-4.21 mg/1, 1.39 mgll, chloride ion 6.23-42.5, 16.7 mg/1, phosphate-phosphorus ND-0.04, 0.02 mg/1, nitrite-nitrogen ND-0.02, 0.01 mg/l, nitrate-nitrogen ND-3.56, 1.42 mg/1, ammonia-nitrogen ND-0.20, 0.14 mg/1, dissolved total nitrogen ND-3.78, 1.57 mgll, iron 0.04-0.28, 0.13ppm, zinc 0.03-0.66, 0.20ppm, mangan ND-0.01, allumium 0.14-0.58, 0.39ppm, copper ND-0.01, 0.01, lead ND-0.01, 0.0lppm, Arsenic ND-0.01, 0.0lppm, mercury ND-0.02, chrome not detected, cadmium not detetced respectively. The viable cell counts of the spring waters ranged 5.0760/m1(means 130/m1). Range and mean value of total coliform and fecal coliform MPN's of the spring waters were 0-2,400MPN/100 ml, 73MPN/100 ml and 0-540MPN/ 100 ml, 21MPN/100 ml. Spring water quality was usually poor with viable cell counts exceeding 130 CFU/liter and the coliform counts in spring waters of 73 MPN/liter. Composition of coliform by IMViC reaction was 33.3% E. coli, 15.6% Citrobacter freundii, 35.6% Klebsiella aerogenes and others.

Effect of gamma irradiation on quality properties of half-cooked noodle was studied. The noodle were treated with lactic acid(0.1%, w/w), heat(10 min in boiling water) or their combination after cooking for 3 min, and irradiated at 0, 5 and 10 kGy. The noodle were stored at 25℃ for 5 weeks and microbial population, Aw, pH, and texture profiles were examined. Fungi were completely eliminated by gamma-irradiation with 5 or 10 kGy does. Number of aerobic bacteria were also decreased by 2 and 4 log cycles with dose of 5 and 10 kGy, respectively. The D_(10) values of aerobic bacteria were 2.34-2.95 kGy. Growth of the aerobic bacteria that survived even at 10 kGy of irradiation were significantly inhibited during storage. Acidification of half-cooked noodle was suppressed by gamma irradiation but A_w were not affected. Stickiness was decreased at the beginning of storage by gamma irradiation but was restored after 3 weeks. The results indicated that the gamma irradiation would be useful to improve quality and storage stability of half-cooked noodle.

This study was carried out to investigate the microbiological and chemical properties of natural water during storage. The water samples were taken at the time of purchase and the opened bottles and the unopened bottles stored at the temperature of 4, 18, and 30. The bacterial content normally rose to 2.06 × 10² CFU/ml for the unopened bottles and 2.91 × 10² CFU/ml for the opened bottles after 2 weeks of storage, and 1.21 × 10^7 CFU/×ml and 2.64 × 10^7, respectively, after 24 weeks of storage. The number of viable cells of bacteria peaked more rapidly at the storage temperature of 30℃ than 18℃. But the total samples were found to be negative for coliforms test during the study period. The average range of pH value was from 7.39 to 7.76. The results showed that the nitrates and chlorides satisfied the Korea Drinking Water Quality Standards during the storage period of 24 weeks. However, the undesirable changes of the taste and odor were detected within 2 weeks and 3 weeks, respectively.

This study was conducted to investigate the effect of chlorine dioxide fumigation as a substitute for sulfur fumigation which has been used as a method to prevent the quality change of persimmon during storage and distribution process. Dried persimmons were treated with chlorine dioxide gas concentration (0, 15 30, and 45 ppm) and time (0, 15, 30, and 45 min) and microbiological changes, texture properties and color of the treated samples were investigated during storage at room temperature. Total aerobic bacteria, yeast and mold numbers after chlorine dioxide gas fumigation were decreased when compared with the control group. The inhibitory effects of total aerobic bacteria, yeast, and mold were observed during storage. The texture properties and color value of dried persimmons were not affected by chlorine dioxide gas fumigation concentration and time. There was no difference in quality between chlorine dioxide gas fumigation treatment group and control group. These results suggested that chlorine dioxide gas fumigation treatment can be utilized as a processing technique to secure microbiological storage stability of dried persimmons.

The objective of this study was to evaluate the changes in the physicochemical and microbiological characteristics of pork loin meat through microwave treatment. The microwave treatment was divided into two groups: continuing microwave treatment (CW) and holding microwave treatment (HW). The microwave treatment resulted in a whiter color (L value) and affected the a, b value. The initial pH was 5.51~5.74, but it increased to 6.32~6.51 when the pork loin samples were stored for three days. During storage for 14 days, the pH changes were not significantly different (p>0.05). The thiobarbituric-acid values of all the pork loin samples increased along with the storage period, and decreased with increasing microwave dose. The volatile basic nitrogen (VBN) content of the control was higher than those of the other samples, and the VBN content decreased along with the microwave dose. The total plate counts of the pork loin samples decreased with increasing microwave dose. The study results indicated that T2 (100 W, HW) is most effective for the safety of pork loin meat without decreasing the meat’s physicochemical and microbiological characteristics.

This study was carried out to investigate the physiochemical and microbiological changes of dandelion during fermentation. Thirty and fifty percentage raw sugar groups (SFE30 and SFE50) were introduced into dandelions and fermented for 120 days at 15-20℃. This study was conducted to investigate the utilization of sucrose on lactic acid bacteria from dandelions and their effect on the pH, titratable acidity, microorganism and formation of organic acids in dandelions during fermentation. The number of lactic acid bacteria increased remarkably up to 15 days of fermentation and then decreased rapidly thereafter. The maximum number of lactic acid bacteria, 7.9 log CFU/mL was reached at pH 4.17 and the pH of dandelion showed a slight decrease during fermentation and decreased steadily up to 90 days to reach an optimum pH of 4.0. The titratable acidity of dandelions fermented increased during fermentation. The concentration of organic acid, amino acid and free sugar in SFE30 was higher than both SFE50 and DWE. The results of dandelions fermented were remarkably retarded in the 50% raw sugar group compared to the 30% raw sugar group.

고추장굴비의 지방산패를 최소화하기 위하여 신선굴비를 동결건조한 굴비포를 사용하여 고추장굴비를 제조하고 비열처리 살균방법으로 초고압과 감마선 처리하여 저장 중에 품질과 미생물변화를 분석함으로서 고추장굴비의 저장과 유통기간 연장 가능성을 검토하였다. 초고압처리(200, 400, 600 MPa) 및 감마선 조사(7, 10, 20, 30 kGy) 후 pH 변화는 유의적으로 차이가 없었으며 20일 동안 상온에서 저장 중에도 시료간의 유의적인 변화를 보이지

찰옥수수를 중 저온에서 장기간 저장할 수 있는 방법을 개발하기 위하여 찰옥수수를 증자하여 진공포장한 후 감마선 조사하여 여러 온도에서 저장하면서 미생물의 생육변화 및 이화학적 성질을 조사하였다. 증자 찰옥수수를 감마선 조사한 후 저장전에 총균수는 3 kGy 조사에서 모두 사멸하였고 곰팡이 및 효모는 34 CFU/g을 나타내었으며, 에서 7개월간 저장 후에 총균수 및 효모, 곰팡이는 대조구에서 를 나타내었으나 3 kGy 조사구에서는 총균수가 검출되

일반적으로 실제 저장 유통되는 조건 하에서 생선의 품질 변화를 예측하기 위하여 대표적 생선인 고등어, 조기, 꽁치를 대상으로 미생물과 pH의 변화를 측정하였다. 고둥어의 저장조건으로는 실제 유통되고 있는 조건인 실온 얼음상과 에 저장하면서 그 변화를 관찰하였으며 조기와 꽁치는 와 4에 각각 저장하면서 저장온도에 따른 변화를 관찰하였다 고등어의 초기 총균수는 3.2CFU/g 이었으며 실온 얼음상에서는 저장 6일 후 8.4까지 증가하였다. 반면,