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Nitrate Content (nitrate + content)

Distribution by Scientific Domains

Medical Sciences	40%

Selected Abstracts

Incidence and geographical distribution of sudden infant death syndrome in relation to content of nitrate in drinking water and groundwater levels

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2001
M. George
Background Previous studies indicate that the enteral bacterial urease is inhibited in victims of sudden infant death syndrome (SIDS). One possible inhibitor of this bacterial activity is nitrate. If ambient pollution by nitrate is involved in the etiology of SIDS only a fraction of the nitrate concentration not infrequently found in drinking water would be enough for this inhibition. Methods Occurrence of SIDS (n = 636) in Sweden during the period 1990 through 1996 were analysed regarding geographical and seasonal distribution in relation to the nitrate concentration in drinking water and changes in the groundwater level. Results Both the birth rate and the incidence of SIDS decreased during the study period. One quarter of the municipalities constituting 11% of the population had no cases, the maximum incidence being 6·5 per 1000 live births. Seasonality: The northernmost parts of the country had its highest incidence when the rest of the country had its lowest incidence, and the occurrence of individual deaths was associated with the recharge of groundwater which increases its nitrate content. The local incidence of SIDS was correlated (rs = 0·34,0·87) to maximally recorded concentrations of nitrate in drinking water. Conclusions The seasonal distribution of SIDS was widely different from the south to the north of the country and seems to be associated with differences in the groundwater level changes subsequent to precipitation, frost penetration, and melting of snow. Use of drinking water with high peak concentrations or great variations in nitrate concentration was correlated to the incidence of SIDS. [source]

Sulfur fertilization and light exposure during storage are critical determinants of the nutritional value of ready-to-eat friariello campano (Brassica rapa L. subsp. sylvestris)

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2009
Giancarlo Barbieri
Abstract BACKGROUND: The nutritional value of fresh vegetables can be affected at different steps within the field-to-market pipeline. Both pre- and post-harvest factors should be considered in order to increase the produce quality and to preserve it until final consumption. In this study the effects of sulfur nutrition during plant growth and light exposure during storage on the nutritional value of ready-to-eat friariello campano (Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort.) were studied. RESULTS: Fresh weight loss was higher in light-storage treatment. During storage, light exposure reduced leaf nitrate content, although no effect could be attributed to sulfur nutrition. Sulfur increased both lipophilic and hydrophilic antioxidant activity. The hydrophilic antioxidant activity linearly decreased during storage, whereas the lipophilic activity increased over time. However, no differences could be attributed to light exposure during storage for this parameter. Results on colorimetric indexes and their relation with the chlorophyll content are also reported. CONCLUSIONS: Ready-to-eat friariello quality may be improved with an enhanced antioxidant activity and reduced nitrate content by combining, respectively, increased sulfur availability during plant growth and exposure to light during storage. On the other hand, light exposure caused a more rapid decline in produce fresh weight during storage. Copyright © 2009 Society of Chemical Industry [source]

Nitrate-nitrite toxicity in cattle and sheep grazing Dactyloctenium radulans (button grass) in stockyards

AUSTRALIAN VETERINARY JOURNAL, Issue 10 2004
RA McKENZIE
Hungry cattle and sheep introduced to stockyards containing a dominant or pure growth of Dactyloctenium radulans (button grass) suffered acute nitrate-nitrite toxicity in four incidents in inland Queensland between 1993 and 2001. Deaths ranged from 16 to 44%. Methaemoglobinaemia was noted at necropsies in all incidents. An aqueous humour sample from one dead steer contained 75 mg nitrate/L and from one dead sheep contained 100 mg nitrate and 50 mg nitrite/L (normal = ca 5 mg nitrate/L). Both lush and dry button grass were toxic. The nitrate content of button grass from within the stockyards ranged from 4.0 to 12.9% as potassium nitrate equivalent in dry matter and from outside the stockyards ranged from <0.2 to 0.4%. These data suggest that urine and faeces in stockyard soil may boost the nitrate content of button grass to a concentration hazardous to hungry ruminants. [source]

Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food

BIOTECHNOLOGY PROGRESS, Issue 3 2010
Nils Tippkötter
Abstract Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L,1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed. © 2010 American Institute of Chemical Engineers Biotechnol. Prog. 2010 [source]