The objective of this study was to analyze hazards for the growing stage of 6 tomato farms (A, B, C; soli farms, D, E, F; Nutriculture farms) located in Gyeongsangnam-do to establish the good agricultural practices (GAP). A total of 144 samples for analyzing hazards collected from cultivation environments (irrigation water, soil, nutrient solution, and air) and personal hygiene (hands, gloves, and cloths) were assessed for biological (sanitary indications and major food borne pathogens) and chemical hazards (heavy metals). Total bacteria, coliform, and fungi were detected at levels of 0.2-7.2, 0.0-6.1, and 0.0-5.4 log CFU/g, mL, hand or 100 cm2, respectively. Escherichia coli were only detected in the soil sample from B farm. In case of pathogens, Bacillus cereus was detected at levels of 0.0- 4.4 log CFU/(g, mL, hand or 100 cm2), whereas Staphylococuus aureus, Listeria monocytogenes, E. coli O157, and Salmonella spp. were not detected in all samples. Heavy metals as a chemical hazard were detected in soil and irrigation water, but levels of them were lower than the permit limit. In conclusion, chemical hazard levels complied with GAP criteria, but biological hazards at the growing stage of tomato farms were confirmed. Therefore a proper management to prevent microbial contamination is needed.

본 연구는 딸기 GAP 모델을 개발하기 위한 기초자료를 제공할 목적으로 서부경남에 소재한 딸기 농장 세 곳을 선정하여 딸기의 재배단계에서의 생물학적(위생지표세균, 병원성 미생물, 곰팡이), 화학적(중금속) 및 물리적(이물) 위해요소를 조사하였다. 먼저 작물, 재배환경, 개인위생을 대상으로 생물학적 위해요소를 분석한 결과, 위생지표세균인 일반세균과 대장균군의 경우 재배환경에서 최대 7.3 및 5.6 log CFU/g, 개인위생에서 6.3 및 5.4 log CFU/hand or 100 cm2, 잎에서 5.3 및 4.7 log CFU/leaf으로 검출되었다. 병원성 미생물의 경우 Bacillus cereus가 토양에서 최대 6.1 log CFU/g, Staphylococuus aureus가 작업자 손에서 5.4 log CFU/hand로 검출되어 이들 병원균에 의한 식중독 발생 가능성 또한 있는 것으로 나타났으며, 공중낙하균의 경우는 안전한 수준으로 나타났다. 화학적 위해요소인 중금속 (Cd, Pb, Cu, Cr, Zn, Ni, Hg 및 As)은 모두 국내 허용기준치 이하로 검출되었고, 물리적 위해요소는 유리조각, 캔 등의 일반쓰레기나 경작지 폐기물 등으로 확인되었다.

본 연구에서는 고추재배 농가에 대한 농산물우수관리제도(Good agricultural practices, GAP) 적용을 위한 미생물학적 위해분석을 수행하였다. 경북 청송에 위치한 고추재배 농가 3곳을 선정한 후 재배환 경·도구, 작물, 작업자 및 공중낙하균에 대하여 시료를 수집하였고, 위생지표세균, 병원성 미생물 및 곰팡이를 분석하였다. 그 결과, 일반세균, 대장균군 및 곰팡이는 3 곳의 농가에서 각각 0.7~6.2, 0.2~4.7, 0.4~4.3 log CFU 수준으로 확인되었고 총 90점의 시료 중 4점의 시료(작물 잎 1점, 농업용 수 1점 및 토양 2점)에서 대장균이 검출되었다. 병원성 미생물 Staphylococcus aureus의 경우 B 농가의 작업복에서만 1.0 log CFU/100 cm2로 검출되었고, Bacillus cereus는 B와 C 농가의 재배환경·도구와 작업자에서 1.0~2.5 log CFU 수준으로 확인되었다. 그러나 다른 병원성 미생물의 경우는 모든 시료에 서 검출한계이하의 수준으로 검출되었다. 이상의 결과로 볼 때 농가에서 재배되고 있는 고추에 대한 잠 재적인 미생물학적 위해가 확인되었고, 이를 최소화할 수 있는 관리시스템, 예를 들면 GAP와 같은 관리 시스템이 미생물학적 위해로부터 고추의 안전성 확보를 위해 적용되어야 할 것으로 판단된다.

콩 GAP 모델 확립을 위해 경남 창녕에 소재한 콩 재배농가 3 곳을 선정하여 각 재배환경에 대한 물리 적, 화학적(중금속) 및 생물학적(위생지표세균, 병원성 미생물) 위해요소를 분석하였다. 재배환경에 대한 물리적 위해요소로는 토양과 농업용수에 혼입될 수 있는 이물 등으로 확인되었고, 화학적 위해요소 중 토 양과 농업용수에서의 중금속 (Cd:0.01~0.103, Cu:0.001~6.036, As:0.006~3.045, Hg:ND~0.041, Pb:0.003~3.952, Cr+6:0.007~0.496, Zn:0.001~66.500, Ni:0.003~18.010)이 모두 허용기준치 이하로 검출되었다. 생물학적 위해요소의 경우, 위생지표세균은 토양에서 일반세균과 대장균군이 6.0±0.3 및 3.6±1.6 log CFU/g, 농업용수는 3.5±0.7 및 1.9±0.7 log CFU/mL 수준으로 각각 검출되었고, E. coli 는 모든 시료에서 불검출 되었다. 그러나 농업용수에서 대장균군이 허용기준치를 초과하였고, E. coli O157도 토양 중에서 약 22%가 검출됨에 따라 분변오염 방지를 위한 적절한 방안이 필요할 것으로 판단 된다. 결론적으로 재배환경 중 물리적 및 화학적 위해요소 (중금속)의 오염수준은 허용기준에 적합했지만, 생 물학적 위해요소의 경우 농업용수에서 대장균군이 기준치를 초과함에 따라 최종산물로의 교차오염을 방지 하기 위한 체계적인 관리방안이 모색되어야 할 것으로 판단된다.

Aflatoxins produced by Aspergillus spp. are recognized as a major concern in animal and human health. In pigs, ingestion of aflatoxin-contaminated feeds causes immunosuppression, hepatotoxicosis and poor feed efficiency. In this study, we screened the contaminated level of aflatoxins in 449 pig feeds from 12 swine farms in Korea. For rapid and efficient screening of aflatoxins in pig feeds we evaluated the feasibility of three commercial ELISA kits for the screening of aflatoxins in pig feeds. Twenty-nine pig feed samples were examined for total aflatoxins using three ELISA kits, simultaneously. From three repetitions of each assay, the average intra-assay precisions and the average inter-assay precisions expressed as coefficient of variation (CV, %) for VeratoxⓇ Quantitative Aflatoxin test were 6.90 and 12.29, respectively. A statistical comparison of the results between HPLC and ELISAs showed that the correlation coefficient values for VeratoxⓇ was 0.96. The results demonstrated that we can apply the VeratoxⓇ Quantitative Aflatoxin test for the detection of aflatoxins in pig feed from the field. The screening of field samples with this ELISA kit showed that 11 out of 265 pig feeds for growers and weaners were contaminated with total aflatoxin levels exceeding 10 ppb, maximum tolerable limits for their compound feeds and the aflatoxins levels of remaining 184 pig feeds for other age groups of pigs were confirmed as below 20 ppb. The results from the screening indicated overall low levels of aflatoxins contamination in pig feeds.

The effect of allylisothiocyanate, the major compound of radish on the growth of Aspergillus parasiticus R-716 and aflatoxin production, was investigated. An increase in the level of allylisothiocyanate results in a decrease both growth and aflatoxin per myclial weight, and the addition of 125 ppm allylisothiocynate completely inhibited the growth of this strain. The addition of allylisothiocyanate to the culture of R-716 strain delayed the production of atlatoxin. The inhibition of aflatoxin was more B-group than G-group and M-group during cultural period. The growth of strain and aflatoxin production were greatly affected by the addition of allylisothiocyanate.

To investigate the antimicrobial effect of polyphosphates as a food additive, the growth and structural change of Listeria monocytogenes Scott A were examined in relation to polyphosphates concentration and incubation temperature. Up to 10,000 ppm of polyphosphates, the growth rate of strain was gradually inhibited with increasing polyphosphates concentration and decreasing the incubation temperature. Minimal inhibitory concentration of polyphosphates to the growth of strain was about 12,000 ppm. It was observed, using both scanning electron microscopy(SEM) and transmission electron microscopy(TEM), that 0.9% polyphosphates treatment was resulted in the destruction of cell wall and outflow of cell ingredients. The antimicrobial effects of polyphosphates were more effective than those of dehydroacetate and potassium sorbate at 13℃ and 4℃. The growth rate of the strain in beef was significantly inhibited by the treatment of 0.9% polyphosphates and storaged at cooling temperature.

The antifungal effects of polyphosphates on the growth and T-2 toxin production of Fusarium sporotrichioides M-1-1 were investigated. The growth of the strain was significantly inhibited in the potatoes dextrose agar medium treated with 1.5% polyphosphates or more. When we checked T-2 toxin by the indirect competitive ELISA, the strain produced 11.25 ug/ml and 10.90 g/ml levels of T-2 toxin in rice and corn containing 50% moisture contents, respectively. However, T-2 toxin was little detected in rice medium and corn medium with 1.5% polyphosphates addition for short(14 days) and prolonged incubation time(45 days). We also observed the destruction of cell wall and outflow of cell ingredients with 1% polyphosphates treatment to the strain. Therefore, moisture and polyphosphates greatly effected on the growth and T-2 toxin production of the strain.

The inhibitory effects of vegetables, collected from Jinju district, on the growth of Listeria monocytogenes were investigated. Among 12 vegetables, garlic, leek, onion and cabbage were remarkably effective to inhibit the growth of the strain. Especially with the addition of extract equivalent 0.25 g of raw garlic per ml broth, the population of the strain was decreased significantly, and completely inhibited with the addition of 0.625 g or more. During the incubation with the addition of extract equivalent 0.25 g of raw garlic per ml broth, the degree of inhibition was gradually increased with the lapse of time, and completely inhibited the growth of the strain after 48 hrs. While the pH value of treated broth remained unchanged almost, those of control were slightly reduced.

In order to establish the enzyme linked immunosorbent assay(ELISA) of sterigmatocystin produced by Aspergillus versicolor, we experimented and obtained following results. Two of three rabbits which had been immunized with sterigmatocystin-hemiacetal-BSA produced antibodies against sterigmatocystin at 15 weeks. The produced antibodies were specific for sterigmatocystin and sterigmatocystin-hemiacetal but didn't cross react with other sterigmatocystin analogues in a significant degree. DMF : 4% KCl (18:2) mixed solution was most effective to dissolve sterigmatocystin. For the preparation of sample solution to determine sterigmatocystin by ELISA, sample was extracted with CHCl₃ and dried, then the dried sample was redissolved with 100 ul DMF+4% KCl mixture. 10-1,000 ng/ml level. of standard sterigmatocystin could be applied to the established ELISA. When artifically contaminated rice were assayed by the ELISA, the average recovery of sterigmatocystin spiked to 25-500 ng/g was 109% (97-116%), and mean interwell coefficient of variation was 21% (11-28%).