[Amount of nitrate and nitrite in daily menus containing more than 350 g of vegetables].

The contents of nitrate and nitrite in menus containing more than 350 g of vegetables per day were investigated. The amounts of vegetables in menu A developed by female students and menu B taken from a recipe book were 350+/-2 g and 457+/-77 g, respectively. The average content of the nitrate was 321.0+/-139.3 mg (104.2-636.9 mg) in menu A, and 245.7+/-90.7 mg (140.1-507.3 mg) in menu B. Sixteen and thirteen samples exceeded the ADI in menus A and B, respectively. This may be because menu A contained more raw vegetables than menu B (menu A; 120+/-58 g, menu B; 72+/-71 g). The contents of nitrite in menu A and B were 1.2+/-0.3 mg (0.7-1.8 mg) and 2.8+/-0.9 mg (1.3-4.6 mg), respectively, and 6 samples in menu B exceeded the ADI. Intake of 350 g of vegetables or more in a day may require careful consideration of selection, frequency of use and cooking method, especially for vegetables with high nitrate content. A questionnaire to female students showed that 80% or more of students recognized that vegetables containing high contents of nitrate, such as spinach and komatsuna, should be boiled before eating them.

[Nitrate and nitrite contents in vegetable juice, tea beverage and mineral water on the market].

The contents of nitrate and nitrite in vegetable juice (n = 63), tea beverage (n = 12) and mineral water (n = 15) were measured. The mean contents of nitrate were 0.73 +/- 14.57 mg/100 g, 0.61 +/- 1.12 mg/100 g and 0.25 +/- 0.33 mg/100 g as NO3-, respectively. The contents of the nitrite were 0.03 +/- 0.05 mg/100 g, 0.02 +/- 0.01 mg/100 g and 0.001 +/- 0.001 mg/100 g as NO2-, respectively. The content of nitrate is high in some vegetable juices, and warnings may be necessary for people who drink them frequently.

[Survey of the daily intake of nitrate and nitrite in school children by the duplicate portion method].

The daily intake of nitrate and nitrite in school children (n = 100) in Hiroshima Prefecture was estimated directly by the duplicate portion method. The daily intake of nitrate was 68.42 +/- 77.49 mg. The daily intake of nitrate/kg body weight was 2.06 +/- 2.24 mg, which is about 56% of the acceptable daily intake (ADI). The daily intake of nitrite was 0.953 +/- 0.869 mg. The daily intake of nitrite/kg body weight was 0.027 +/- 0.021 mg, which is about 45% of the ADI. The daily intake of nitrite/kg body weight was significantly different between the obese group and the non-obese group in boys (p < 0.05, Mann-Whitney U-test). The rates of children whose daily intakes of nitrate and nitrite were above the ADI were 16% and 7%, respectively.