• Journal of Food Hygiene and Safety
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• v.11 no.1
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• pp.1-5
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• 1996

This study is performed to identify the contents of nitrosamine in meat (beef, pork) and meat product (ham, bacon, sausage) by gas chromatograph-thermal energy analyzer. The author also determained the formation of nitrosamine in these products when they were cooked in frying pan at 21$0^{\circ}C$ for 4 minutes and microwave for 45 and 75 seconds. N-ni-trosodimethylamine (NDMA) analysis was impossible in the most products because of their impurieties. On the other hand, N-nitrosopyrrolidine (NPYR) of 0~9.4 ug/kg in meat and 0~15.6 ug/kg in meat products were detected, respectively. When meat and meat products were cooked, generally contents of NDMA and NPYR have a tendency to be increased a little. Meat and product being cooked in microwave rather than frying pan, contents of NDMA and NPYR were detected more. Especially, in sausage contained much flsh, contents of NDMA was detected more.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.6-9
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• 1996

A total of 47 beer samples, produced in Korea. Were analyzed for their N-nitrosamine levels by gas chromatography-thermal energy analyzer. N-nitrosodimethyamine(NDMA) was detected in 35 of 47 sam-ples analyzed. The range of levels was 0~7.2$\mu\textrm{g}$/kg while the average was about 0.9mg/kg. The identity of NDMA was confirmed by mass spectrometry. Samples which were found only NDMA before nitrosation were detected to include N-nitrosopyrroidine(45$\mu\textrm{g}$.kg) and N-nitrosomorpholine(4$\mu\textrm{g}$/kg) as well as NDMA(837$\mu\textrm{g}$/kg)

• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.29-35
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• 2002

N-nitrosamine(NA) contents depending on simulated gastric digestion were analyzed with 12 kinds of diets collected from institutional food service those diets were estimated the total NA amounts including both intake from food directly and its endogenous formation in human body from simulated gastric digestion. NA was determined in dishes of meats, fishes and vegetables before and after simulated gastric digestion. Before digestion, N-nitrosodimethylamine (NDMA) contents ware from not detected(ND) to 4.8$\mu\textrm{g}$/kg in dishes of meats and fishes. After digestion, its contents increased and the highest level was 3.0 $\mu\textrm{g}$/kg in panbroiled dried anchovy. In vegetable dishes, NDMA was detected as ND∼trace before and after digestion. The contents of NDMA in diets collected from institutional food service were 0.20∼0.78$\mu\textrm{g}$/kg 0.43 ∼ 0.80$\mu\textrm{g}$/kg before and after digestion, respectively. The average intake of NA per day to Korean, based on the above data, was 0.60 ∼ 2.34$\mu\textrm{g}$/day/ person. The maximum daily intake of NA was deduced to 5.15$\mu\textrm{g}$/day/person when considering NA amounts formed endogenously by simulated gastric digestion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.149-153
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• 1992

The antimutagenic effect of green-ye1low vegetables on the mutagenicities induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and N-nitrosodimethylamine (NDMA) in Salmonella assay system and also their inhibitory effect on AZ-521 human gastric cancer cells were studied. Twenty-four items from twenty six kinds of vegetables(92%) revealed antimutagenic activity toward MNNG (p< 0.0l, 0.05). Perilla leaf, Korean cabbage, cauliflower, lettuce, mustard leaf, water dropwort, small water dropwort, carrot and burdock inhibited the mutagenicity more than 80%. The methanol extracts of the vegetables also showed the antimutagenic activity toward NDMA (p< 0.01, 0.05). Especially, perilla leaf, kale, soybean sprout and onion inhibited more than 80% of the NDMA induced mutagenicity in S. typhimurium TA100. Small water dropwort and perilla leaf exhibited the strong inhibitory effect (97~100%) on the growth of the AZ-521 human gastric cancer cells. Soybean sprout, water dropwort, broccoli, crown daisy, green red pepper, red pepper leaves, spinach, cabbage and sweet potato also inhibited growth of the cancer cells (p < 0.001~0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.125-135
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• 1988

In recent years, the presence of N-nitrosamine, which was produced by the interaction of nitrite and secondary amine, in the fermented foods has been the subject of considerable interest and controversy. In this experiment, the levels of N-nitrosamine such as N-nitrosodimethylamine(NDMA), N-nitrosodiethylamine(NDEA) and N-nitrosodipropylamine(NDPA) in the Korean ordinary soysauce, which were added with ascorbic acid, sorbic acid, and sodium benzoate in the making of it were analyzed by low resolution mass spectrometry, and then the changes of dimethylamine(DMA), nitrate and nitrite nitrogen during the fermentation of it were observed. The contents of DMA nitrogen increased during the fermentation of Korean ordinary soysauce, continuously, but those of DMA nitrogen in the soysauce which had been added with ascorbic acid were inhibited, considerably, until the fermentation of 70days. The levels of nitrate nitrogen during the fermentation of Korean ordinary soysauee decreased, while those of nitrite nitrogen increased. The soysauce which had been incoporated with ascorbic acid in the making of it showed low amounts of nitrite. The concentration of NDMA in the control sample were 2.7 and $8.5{\mu}g/kg$ after the fermentation of 30 and 60 days, respectively, those of NDMA increased during the fermentation of Korean ordinary soysauce, but NDEA and NDPA in all of the soysauce were not detected. The samples were treated with ascorbic acid, sorbic acid, and sodium benzoate in the making of Korean ordinary soysauce were turn out to be effective in preventing the formation of NDMA. Inhibitive actions from food additives as above were, respectively, $82.2{\sim}87.0%$(ascorbic acid), $25.9{\sim}65.4%$(sorbic acid) an $13.2{\sim}63.5%$ (sodium benzoate) in comparison with control sample during the fermentation of Korean ordinary soysauce. NDMA contents were detected below $1.5{\mu}g/kg$ in the soysauce, which food additives were mixed to the pure NaCI in the brewing of it. Free amino acids such as glutamic acid, proline, and histidine were proved to be inhibiting the formation of NDMA during the fermentation of Korean ordinary soysauce. This might be due to the reaction above amino acids and nitrite by Van Slyke reaction.

• Journal of Life Science
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• v.16 no.5
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• pp.794-798
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• 2006

A tomato (Lycopersicon esculentum cv. Naomi F1) juice was separated into ascorbate and phenolic portions using a Sep-pak $C_{18}$ cartridge, and its each portion was tested for inhibition of N-nitrosodimethylamine (NDMA) formation. Ascorbate and phenolic portions of tomato juice inhibited NDMA formation by $81.37{\pm}0.25%$ and $72.03{\pm}0.25%$, respectively. The phenolic portion was further fractionated by prep-HPLC and inhibitory effects of NDMA formation by 4 fractions $(1{\sim}4)$ from tomato juice was tested under the different pH conditions (pH 1.2 and 4.2). Fraction 2 inhibited NDMA formation by $50.10{\pm}0.46%$ (pH 1.2) and $64.30{\pm}0.20%$ (pH 4.2), respectively. Fraction 2 was further separated into 4 subfractions $(2a{\sim}2d)$. Subfraction 2b especially inhibited NDMA formation by $70.62{\pm}0.45%$ (pH 1.2) and $75.30{\pm}0.45%$ (pH 4.2). This subfraction was confirmed o-coumaric acid through the analysis of GC-Mass spectrum, $^1H-NMR$ and $^{13}C-NMR$.

• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.16-22
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• 2002

The effects of nitrite scavenging. electron donating and N-nitrosodimethylamine(NDMA) formation in vitro arid green tea(Camellia sinensis) and Maesil(Prunus mume) were studied. The green tea and Maesil extracts were tested for their nitrite-scavenging effect under the different pH conditions such as pH 1.2, 4.2 aud 6.0. The effects of nitrite-scavenging in all concentrations were diminished in the alkali condition, while its effects in the acidic condition of pH 1.2 were reached of more than 99.0% by adding above 0.5ml of green tea extract. And also, nitrite-scavenging effect by adding 3ml of Maesil extract was about 77.0%. The electron donating ability(EDA) of green tea and Maesil extracts was 70.6%, 75.1%, respectively. The formation of NDMA was very effectiveness which was inhibited 82.1%, 73.2% at reaction mixture of pH 2.5 adding 3ml of above extracts. respectively . The ground CW. TW1 and TW2 (refer to Table 1) diets were incubated with 10m1 simulated saliva and 40m1 gastric juice at 37$^{\circ}C$ for 2hrs. NDMA formation was inhibited at all levels of green tea and Measil extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.223-229
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• 2003

An amine rich diet with nitrate was incubated in simulated saliva, gastric juice, kale juice, and its ascorbate and methanol soluble portions (5, 10, 15 and 30 mL) for 1 hr at 37$^{\circ}C$ and N-nitrosodimethylamine (NDMA) was detected in the digestion sample, Kale juice and its ascorbate and methanol soluble portions at 30mL inhibited NDMA formation by 60.1$\pm$4.4%, 49.3$\pm$1.2% and 50.1$\pm$2.0%, respectively. The methanol soluble portion was further fractionated by preparative-LC (prep-LC). Nitrite-scavenging effects of 7 methanol soluble portion (Kl, K2, K3, K4, K5, K6 and K7) in kale juice were 2.0 ~56.2%. Among seven fractions, K3, K4, K5 and K7 exhibited weakly on nitrite scavenging effect. Fraction Kl and K2 inhibited NDMA formation by 71.0 and 65.5%, respectively. Fraction Kl and K2 was further separated by prep-LC into 6 subfractions (Kla, Klb, Klc, K2a, K2b and 2nc). Those subfractions inhibited NDMA formation by 40.9 ~80.4%. The K2a subfraction was screened by MS, $^1$H-NMR, $^{13}$ C-NMR and DEPT spectrum.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.378-383
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• 2002

The aim of the study was to analyze N-nitrosamine (NA) and its precursors in serveral fermented foods which were treated with nitrite, thiocyanate and ascorbic acid under simulated gastric digestion. Every analyzed sample contained nitrate, with levels ranging from 0.3 to 1.3 mg/kg, but nitrite was present at very low levels of less than 0.3 mg/kg. And other precursors of amines such as dimethylamine and trimethylamine were detected less than 0.5 mg/kg in every samples. N-nitrosodimethylamine (NDMA) was detected in the levels of <0.5 ∼ 2.7 ug/kg in soy sauce,1.5∼3.1 ug/kg in soybean paste and <0.5∼1.8 ug/kg in beer, while NDMA levels increased by 1.1∼4.5 times in the fermented foods which were digested under simulated gastric conditions.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.94-100
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• 2002

This work was performed in order to examine the effect of nitrite, thiocyanate and ascorbic acid on formation of N-nitrosamine(NA) in kimchi, fermented anchovy and shrimp under simulated gastric digestion, in vitro. The contents of nitrate were 10.7~24.5 mg/kg in kimchi, 1.5~5.6 mg/kg in fermented anchovy, 1.0~2.0 mg/kg in fermented shrimp and those of nitrite were average 0.3 mg/kg in all analyzed samples. Dimethylamine and trirmethylarnine contents were 4.9~l5.4 mg/kg, 0.6~0.8 mg/kg in kimchi, 3.3~4.0 mg/kg, 1.9~2.8 mg/kg in fermented anchovy, 30.3~177.9 mg/kg, 4.4~21.3 mg/kg in fermented shrimp, respectively. The contents of N-nitrosodime -thylamine(NDMA) were in the range of 0.8~6.9 $\mu\textrm{g}$/kg in kimchi, 0~l.2 $\mu\textrm{g}$/kg in fermented anchovy and 0~0.9 $\mu\textrm{g}$/kg in fermented shrimp. After simulated gastric digestion, NDMA was increased about 1.5 times in all sample. In every nitrite added samples, the contents of NDMA were increased by 183.1 times in fermented shrimp and were detected 192.4 $\mu\textrm{g}$/kg and 220.9 $\mu\textrm{g}$/kg when it was treated with 4 mM and 8 mM of nitrite, respectively. NDMA, when above samples were added 8 mM nitrite and 6.4 mM thiocyanate, was increased about 1.5 times than control samples. The formation of NDMA was inhibited by 49.9~92.4% in all samples added 12.8 mM ascorbic acid compared with the control sample.