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Nitrite Content (nitrite + content)
Selected AbstractsNitrite accumulation characteristics of high strength ammonia wastewater in an autotrophic nitrifying biofilm reactorJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2003Ho-Joon Yun Abstract Selective nitrification was carried out to accumulate nitrite from high strength ammonia wastewater in an autotrophic nitrifying biofilm reactor. Nitrification efficiencies and nitrite accumulation characteristics were investigated at various operating conditions such as ammonium load, oxygen supply and free ammonia concentration. The biofilm reactor showed very stable nitrification efficiencies of more than 90% at up to 2,kg,NH4 -N,m,3,d,1 and the nitrite content was maintained at around 95%. Inhibition by free ammonia on nitrite oxidizers seems to be the major factor for nitrite accumulation. Batch kinetic analyses of ammonium and nitrite oxidation showed that nitrite oxidation activity was selectively inhibited in the presence of free ammonia. However, the activity recovered quickly as the free ammonia concentration decreased below the threshold inhibition concentration. Examination of specific ammonia and nitrite oxidation activities and the most probable number indicated that the number of nitrite-oxidizing microorganisms in the nitrite-accumulating system was less than that in the normal nitrification system due to long-term free ammonia inhibition of the nitrite oxidizers. The reduced population of nitrite oxidizers in the biofilm system was also responsible for the accumulation of nitrite in the biofilm reactor. © 2003 Society of Chemical Industry [source] Effects of Varying Levels of Vegetable Juice Powder and Incubation Time on Color, Residual Nitrate and Nitrite, Pigment, pH, and Trained Sensory Attributes of Ready-to-Eat Uncured HamJOURNAL OF FOOD SCIENCE, Issue 6 2007J.J. Sindelar ABSTRACT:, Vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus have been identified as necessary ingredients for the manufacture of uncured, no-nitrate/nitrite-added meat products with quality and sensory attributes similar to traditional cured products. The objectives of this study were to determine the effects of varying concentrations of VJP and incubation time (MIN-HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of ham over a 90-d storage period, compare residual nitrate and nitrite content, and determine if differences exist in sensory properties of finished products. Four ham treatments (TRT) (TRT 1: 0.20% VJP, 0 MIN-HOLD; TRT 2: 0.20% VJP, 120 MIN-HOLD; TRT 3: 0.35% VJP, 0 MIN-HOLD; TRT 4: 0.35% VJP, 120 MIN-HOLD) and a sodium nitrite-added control (C) were used for this study. No differences (P > 0.05) were observed between TRTs and C for CIE L*, a*, b*, and cured color measured by reflectance ratio. Lipid oxidation (TBARS) for combined TRTs and C revealed little change over time while the C had less (P < 0.05) lipid oxidation than TRTs 2 and 4 for combined days. No differences (P > 0.05) were reported for cured pigment concentration between TRTs and C. Trained sensory panel intensity ratings for ham and vegetable aroma, and flavor, color, and firmness showed that a high concentration (0.35%) of VJP resulted in the highest scores for undesirable vegetable aroma and flavor. Treatment combinations with a low concentration (0.20%) of VJP were comparable to the C for all sensory attributes. [source] Effects of Vegetable Juice Powder Concentration and Storage Time on Some Chemical and Sensory Quality Attributes of Uncured, Emulsified Cooked SausagesJOURNAL OF FOOD SCIENCE, Issue 5 2007J.J. Sindelar ABSTRACT:, Uncured, no-nitrate/nitrite-added meat products can be manufactured with vegetable juice powder (VJP) and a starter culture containing Staphylococcus carnosus, resulting in quality and sensory attributes similar to traditional cured products. The 1st objective of this study was to determine the effects of varying concentrations of VJP and incubation times (MIN-HOLD) on quality characteristics, including lipid oxidation, color, and cured meat pigment concentrations, of emulsified-frankfurter-style-cooked (EFSC) sausages over a 90-d storage period. The 2nd objective was to compare residual nitrate and nitrite content resulting from different processing treatments and the 3rd objective was to assess sensory properties of finished products. Four EFSC sausage treatments (TRT) (TRT 1: 0.20% VJP, 30 MIN-HOLD; TRT 2: 0.20% VJP, 120 MIN-HOLD; TRT 3: 0.40% VJP, 30 MIN-HOLD; TRT 4: 0.40% VJP, 120 MIN-HOLD) and a sodium nitrite-added control (C) were used for this study. No differences for lipid oxidation (TBARS) between any TRTs and C or over time were observed. No differences (P > 0.05) for CIE L* values were found between TRTs. CIE a* and reflectance ratio values revealed that TRTs 2, 4, and C were redder than TRTs 1 and 3 at day 0. Trained sensory intensity ratings for cured aroma, cured color, cured flavor, uniform color, and firmness determined that all but TRT 1 were similar to C. These results indicate a longer incubation time (120 compared with 30 min) was found more critical than VJP level (0.20% or 0.40%) to result in products comparable to a sodium nitrite-added control. [source] Analysis of the possibility of the relationship between various implant-related measures: an 18-month follow-up studyJOURNAL OF ORAL REHABILITATION, Issue 2 2008T. F. TÖZÜM Summary, Better clarification of the long-term relationship among the various implant-related measures could improve the evaluation process for dental implants. Thus, the aim of the present study was to determine the potential correlations among the volumetric features and nitric oxide content of peri-implant sulcus fluid (PISF) and measures of implant stability, and the marginal bone loss. Completely edentulous patients (n = 15) treated with dental implants and ball attachment mandibular over dentures were included. Resonance frequency analysis (RFA), marginal bone level measurements, PISF volume and spectrophotometrically determined nitrite levels were recorded for all dental implant sites. Measures for early (n = 16) and delayed (n = 14) loaded dental implants were comparatively analysed for a period of 18 months. Some random correlations between PISF volume and marginal bone level, PISF nitrite level and marginal bone level and PISF volume and PISF nitrite content, and RFA and PISF volume were observed. However, the only constant correlation was noticed between implant stability (RFA scores) and marginal bone level. This correlation was negative and significant for all dental implants and for delayed loaded implants (P < 0·05). The pattern of loading seemed to affect the extent, but not the pattern of this relationship. While some of the implant-related measures may be strongly associated (e.g. dental implant stability and marginal bone level), not all measures from a single implant site are likely to be related. Such associations may be under the influence of a variety of factors including the loading protocol of dental implants. [source] Role of shear stress on nitrite and NOS protein content in different size conduit arteries of swineACTA PHYSIOLOGICA, Issue 2 2009X. Guo Abstract Aim:, Inherent fundamental difference exists among arteries of different sizes. The purpose of this study was to evaluate the relation between regional difference of wall shear stress (WSS) in various sizes arteries and contents of nitrite and NO synthase (NOS) isoforms. Methods:, Five different conduit arteries in a wide range of diameter (1,8 mm) were examined in the hind limbs of 13 pigs. Blood flow rate and outer diameter were measured in vivo to determine WSS. Arterial tissues were harvested for the measurement of nitrite and NOS protein contents. The concentration of nitrite, a product of NO synthesis, was determined by high-performance liquid chromatography method. Western blot analysis was used to assess the protein contents of endothelial NOS (eNOS), inducible NOS (iNOS) and neuronal NOS (nNOS). Results:, Our data show that WSS increases with a decrease in artery diameter. Nitrite level increases with increasing WSS and hence decreases with artery diameter. The eNOS protein contents decrease with an increase in diameter. No significant difference for iNOS and nNOS protein contents was found with different artery diameter. A significant positive correlation between tissue nitrite and eNOS protein contents was also observed. Finally, the WSS-normalized eNOS is not significantly different in various size vessels. Conclusion:, Regional difference in blood flow has no effect on iNOS and nNOS protein contents in these conduit arteries. Regional difference in eNOS expression and nitrite contents may be related to the WSS-induced NO by the endothelium under normal physiological conditions. [source] | ||||||||||