• 방사선산업학회지
• /
• 제17권3호
• /
• pp.257-264
• /
• 2023

This study was conducted to evaluate the applicability of the Comet assay, which is widely used for the identification of irradiated meats, to detect irradiated beef cut, ground beef, and Tteokgalbi during freezing storage. Gamma-irradiation significantly increased the DNA damage in frozen beef cut and ground beef samples. Among those, DNA nuclei of samples irradiated with absorbed doses of 1kGy or more showed typical comet-shaped damage, convincing that the samples were irradiated. Meanwhile, DNA nuclei in non-irradiated beef cut and ground beef samples were also damaged according to storage time. In particular, since the damage of DNA nuclei in the non-irradiated samples frozen for three months was similar to that of samples irradiated with a dose of 0.5 kGy, it was considered difficult to detect whether these samples were irradiated by Comet assay analysis. Likewise, gamma-irradiation of Tteokgalbi increased DNA damage. However, significant damage to DNA nuclei was observed even in the non-irradiated samples. Therefore, the application of the analysis method to determine whether the Tteokgalbi sample was irradiated was not appropriate. In conclusion, these results suggest that Comet assay could be limitedly applied only to fresh meat with a short storage period and minimal processing.

• 한국식품영양과학회지
• /
• 제28권3호
• /
• pp.638-645
• /
• 1999

This study was done to investigate effects of ${\gamma}$ irradiated beef feeding on the formation of gluta thione S transferase placental form positive(GST P+) foci, lipid peroxidation, cytochrome P450 system and microsomal glucose 6 phosphate activity in diethylnitrosamine(DEN) initiated rat hepatocarci nogenesis. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiatied ground beef at the dose of 0, 3, 5kGy as a 20% of protein source for 8 weeks. One week after feeding, rats were intraperitoneally injected twice with a dose of DEN(50mg/kg BW). As a promoter, 0.05% phenobarbital was fed in drinking water from one week after DEN treatment until the end of experiment. At the end of 8th week, rats were sacrificed and hepatic GST P+ foci, microsomal malondialdehyde(MDA) and conjugated diene contents were determined. In addition, cytochrome P450 content and the activities of NADPH cytochrome P450 reductase and glucose 6 phosphatase were also measured. There was no significant effect by gamma irradiation on microsomal MDA content, conjugated diene, cytochrome P450 content and activities of NADPH cytochrome P450 reductase and glucose 6 phosphatase. However with DEN treatment, microsomal MDA content and conjugated diene contents were significantly changed. Cytochrome P450 content was also significantly increased while microsomal glucose 6 phophatase activity was significantly decreased with DEN treatment. However activity of NADPH cytochrome P450 reductase was not affected. An interesting finding in this study was that the number and area of hepatic GST P+ foci of the rats fed gamma irradiated beef were significantly(p<0.05) lower than those of the control. Such a lowering effect on GST P+ foci formation was highest at the dose of 3kGy than others. Overall results suggest that the consumption of low dose of gamma irradiated beef does not affect the formation of lipid peroxide, cytochrome P450 system and membrane stability.

• 한국식품영양과학회지
• /
• 제28권3호
• /
• pp.646-653
• /
• 1999

This study was done to investigate the effect of ${\gamma}$ irradiated beef feeding on antioxidant vitamin levels and defense enzyme activities in diethylnitrosamine(DEN) initiated rats. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiated ground beef at the dose 0, 3, 5 kGy as a 20% of protein source for 8 weeks. One week after feeding, rats were intraperitoneally injected twice with a dose of DEN(50mg/kg BW). As a promoter, 0.05% phenobarbital was fed in drinking water from one week after DEN treatment until the end of experiment. At the end of 8th week, serum level of vitamin C, serum and hepatic levels of retinol and tocopherol were determined. In addition, activities of cytosolic glutathione peroxidase, glutathione reductase, glutathione S transferase, catalase and hepatic superoxide dismutase(SOD) were measured. By ${\gamma}$ irradiation, there was no significant effect on serum and hepatic levels of vitamin C and tocopherol except a significant decreasing effect on hepatic retinol level. There was also no significant effect on the activities of enzymes involved in antioxidative defense system, However, DEN treatment led to a significant increase in activities of glutathione reductase and glutathione S transferase while the activity of glutathione peroxidase was decreased. The activities of hepatic SOD and catalase were not changed by DEN treatment. Overall results indicate that the consumption of low dose of ${\gamma}$ irradiated beef does not affect antioxidative defense system.

• 한국식품과학회지
• /
• 제31권4호
• /
• pp.1005-1010
• /
• 1999

감마선 조사가 쇠고기의 연도개선에 미치는 효과를 조사하기 위하여 도축 직후 쇠고기에 감마선을 조사시켜 전단력의 변화 및 근육의 미세구조를 관찰하였다. 감마선이 조사된 쇠고기는 최고 전단력치에 도달하는 시간이 감마선 조사선량이 증가함에 따라 단축되었다. 감마선 조사가 근육의 초미세구조에 작용하여 근절의 단축을 지연시켰고, Z-line의 수축을 유도하였다. 또한 감마선이 조사된 쇠고기에서 근속과 perimysium의 파괴는 감마선 비조사구에 비해 더 빨리 진행되는 것이 관찰되었다. 결론적으로 감마선 조사는 쇠고기의 사후경직에 도달하는 시간을 단축시키고, 연도개선 효과에 유효한 것으로 사료된다.

• Preventive Nutrition and Food Science
• /
• 제7권1호
• /
• pp.57-61
• /
• 2002

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated dried seasoning powder. Seasoning powders of dried squid flavor, shrimp flavors, kimchi flavor, spicy beef soup flavor and soy sauce flavor were irradiated with doses of 0, 1, 3, 5, 7 and 9 kGy at room temperature using a Co-60 irradiator. Characteristic signals of free radicals were observed in all the irradiated samples of this experimental while these signals were not detected in non-irradiated samples. Since the free radical concentrations linearly increased with the applied doses (1~9 kGy), highly positive correlation coefficients ($R^2$ = 0.9285~0.9965) were obtained between irradiation doses and free radical concentrations during all the storage times. Free radical concentrations of the irradiated flavored seasoning powder did not change even at 16 weeks of storage at room temperature, while those of dried squid, shrimp and spicy beef soup flavors decreased until 2 weeks of storage after irradiation with 5 kGy or over, and these of soy cause flavors slowly decreased until 8 weeks of storage after irradiation with 3 kGy or over. Although the free radical concentrations decreased with storage times, the characteristic signals of the irradiated seasoning powders of dried squid, shrimp, spicy beef and soy sauce flavors were observed even after 16 weeks of storage at room temperature.

• 한국식품과학회지
• /
• 제30권5호
• /
• pp.1184-1188
• /
• 1998

한우육의 사태(M.Semitendinosus)를 대상으로 방사선 조사선량(0, 1, 3, 5 kGy), 포장방법(함기, 진공) 및 저장기간에 따른 육색소(myoglobin, oxymyoglobin, metmyoglobin)와 Hunter값의 변화를 측정하였다. Hunter값의 경우 저장기간이 경과함에 따라 명도와 황색도는 증가하는 경향을 나타내었으나, 적색도는 감소하였고, 감마선 조사에 의한 영향으로는 명도, 황색도, 적색도값이 조사선량이 증가함에 따라 감소하였다. Myoglobin의 함량은 저장기간이 경과할수록 모든 시험군에서 감소를 나타내었고, oxymyoglobin과 metmyoglobin은 점차적으로 증가하였으며, 방사선 조사에 따른 영향은 조사선량이 증가함에 따라 myoglobin은 감소되고 oxymyoglobin과 metmyoglobin은 다소 증가하는 경향을 나타내었다. 포장방법에 따른 영향에서는 함기 포장군이 진공포장군에 비해 더 큰 육색소의 변화를 나타내었다.

• 한국축산식품학회지
• /
• 제18권3호
• /
• pp.232-239
• /
• 1998

This experiment was conducted to investigate radurization effects of gamma ray and electron beam irradiation at 1.5 and 3.0 kGy on beef steaks during 8 days of storage at 5$^{\circ}C$. Total bacteria count, psychrotrophs, mesophiles and thermophiles were analyzed at 2 days intervals. Nonirradiated beef steak was used a scontrol Total bacteria counts, psychrotrophs, mesophiles and thermophiles of the control samples showed 3.03∼4.72 logCFU / g at 0 day and increased to 7.67∼10.90 logCFU / g during 8 days storage except thermophiles. Total bacteria counts, psychrotrophs and mesophiles of beef steaks at 8 days were significantly (p＜0.05) decreased to 3.61∼5.43 logCFU / g by gamma ray and to 3.83∼7.02 logCFU / g by electron beam irradiation at 1.5 and 3.0 kGy. Thermophiles of all irradiated samples at any dose were not detectable through 8 days storage. These results suggested that both gamma ray and electron beam irradiation were effective to extend lag phase of bacterial growth of refrigerated beef. Gamma ray irradiation was better than electron beam irradiation in terms of radurization effects of beef.

• 한국식품과학회지
• /
• 제32권2호
• /
• pp.363-372
• /
• 2000

한우육의 위생화와 품질보존을 위해 $1{\sim}5\;kGy$의 감마선을 조사하였다. 초기 시료에 오염된 미생물의 살균을 위해서는 3 kGy의 선량이 요구되었다. 5 kGy 이상으로 조사된 시료는 $5^{\circ}C$ 8주후에도 미생물의 생육이 관찰되지 않았다. 저장중 pH변화의 경우 저장기간에 따라 다소 증가하는 경향을 보였으나, 감마선 조사에 의한 영향은 거의 없었다. 지질산가는 냉장저장시 감마선 조사 및 비조사 시료 모두 저장기간에 따라 증가하였으나, 3 kGy 조사시료는 비조사 시료보다 완만한 증가를 나타냈다. VBN함량의 경우 냉장저장시 큰 변화를 나타내었고, 비조사 시료는 저장기간이 경과됨에 따라 크게 증가하였다. 특히 냉장저장 8주후의 비조사 시료는 3 kGy조사 시료에 비해 약 4배의 증가를 나타내었다. 지방산 조성은 감마선조사에 의해 큰 영향이 없었으며, 유리 아미노산 함량은 감마선 조사보다는 저장기간에 의해 많은 변화를 나타냈다.

• 한국식품영양과학회지
• /
• 제28권4호
• /
• pp.858-864
• /
• 1999

육제품의 품질 개선을 위한 감마선 조사의 효과를 평가하기 위하여, 감마선 조사된 우육을 이용하여 유화형 소시지(bologna sausage)를 제조하였고, 항산화제와 감마선 조사를 병용처리하여 재구성 육제품인 햄버거 패티를 제조하였다. 3 kGy의 감마선 조사를 이용하여 기존의 첨가량에 비해 낮은 함량의 소금(1.2%)과 인산염(0.2­~0.3%)을 함유한 bologna sausage를 제조할 수 있었다. 또한, 3 kGy의 감마선을 이용하여 bologna sausage의 저장성에 있어서도 $10^{\circ}C$에서 30일 저장까지 어떠한 호기성 미생물의 생육도 검출되지 않았다. 햄버거 패티 제조시 BHA, ascorbyl palmitate, ${\alpha}-tocopherol,\;or\;{\beta}-carotene$을 200ppm 수준으로 첨가하여 제조된 최종제품에서 3 kGy의 감마선 조사는 $10^{\circ}C$에서 저장 30일째까지 호기성 미생물의 생육이 발견되지 않았으며, 항산화제의 첨가로 감마선 조사에 의한 햄버거 패티의 지방산패를 억제시킬 수 있었다.

• 한국식품영양과학회지
• /
• 제29권6호
• /
• pp.1025-1029
• /
• 2000

방사선 조사된 쇠고기와 돼지고기의 방사선 조사 여부를 판별하는데 DNA comet assay의 활용 가능성을 검토하였다. 쇠고기와 돼지고기는 Co-60 동위 원소를 조사원으로 하여 0.1, 0.3, 0.5, 0.7, 1.0 kGy의 총흡수선량( $\pm$ 5.0%)이 되도록 조사하여, 냉동상태로 보관하였다. 시료로부터 분리 된 세포는 agarose gel과 혼합하여 슬라이드에 깔아주고, lysis 및 전기영동을 하였다. 방사선 조사된 시료의 경우 세포로부터 끌려나오는 DNA절편들은 양극을 방향으로 tail이 형성되었고, 비조사 시료의 경우 tail이 없거나, 일부에서만 작은 tail이 관찰되었다. 방사선 조사유무는 0.1 kGy부터 현미경상으로 검지가 가능하였고, 선량간 차이의 유의성 여부는 통계분석을 통하여 검지가 가능하여, 쇠고기와 돼지고기의 신속한 검지 방법으로 DNA comet assay를 활용할 수 있을 것이다.