Background: The assessment of altered nitric oxide (NO) availability is of potentially important diagnostic and prognostic significance. The present study is aimed to investigate the effect of L-arginine (as a natural NO donor) supplementation on NO metabolite in a rabbit model of hypercholesterolemia to find a reliable marker for endothelial NO production. Methods: White male rabbits (n = 30) randomly assigned to 2 groups. Rabbits were fed 1% high-cholesterol diet (HC group, n = 15), or HC diet with oral L-arginine (3% in drinking water) (HC + L-arginine group, n = 15) for 4 weeks. The serum levels of lipids, L-arginine, total NO metabolites (NOx), NITRITE and nitrate were measured before and after the study. Results: In this study, Larginine supplementation led to a significant increased plasma level of L-arginine. The serum level of NITRITE was significantly higher in L-arginine treated group while serum level of nitrate and NOx was significantly lower than HC group. Conclusion: As the result of our study showed, NITRITE is a useful marker of endogenous endothelial NO production and although frequently used, neither nitrate nor NOx are reliable markers of acute changes in endothelial NO synthase activity.

NITRITE is responsible for some characteristics of cured meat products such as color, flavor and suppressingthe outgrowth and production of toxin from Clostridium botulinum. Despite all of its desired properties, NITRITE isresponsible for the formation of carcinogenic N-nitrosamine. In this study, NITRITE-free and low-NITRITE meatcuring systems were developed to eliminate or reduce NITRITE from meat products. Thirteen different formulationswere made including standard frankfurter ingredients with or without NITRITE in combination with cochineal andpaprika as natural coloring agents. For example, control sample was with 120 mg/kg NITRITE, low-NITRITE samplewas contained 40 mg/kg NITRITE and some samples were without NITRITE. The samples were stored at 4oC for eightweeks. During the storage, color changes (L*, a*, b*) were determined and evaluated. Also, the producedsamples were exposed to natural and artificial light and their color stability were compared. In addition, thecolors of samples were evaluated by trained panelists. The results showed that the sample with 40 mg/kg NITRITEand 0.002 % cochineal, the sample contained 40 mg/kg NITRITE and 1 mg/kg paprika and the sample withoutNITRITE and contained 0.015 % cochineal had no significant different color (p<0.05) from the control sample. Overall, it is possible to produce NITRITE- free or low- NITRITE frankfurter sausage with acceptable color.

Microfluidic analytical/diagnostic tools, especially microfluidic paper-based analytical devices ( PADs) have attracted considerable attention due to their numerous advantages including their low operational costs, small analyte consumption, and limited required skills for use, and easy disposal/recycling. μ PADs have been successful in detection of various diseases with no external deriving units. The aim of this study is to develop a micromixer for colorimetric detection of NITRITE in saliva using Griess reaction and widening the limit of detection (LOD) by mixing improvement. Micromixers were fabricated using laser cut after a simple design. Five different geometries were examined and compared including straight, curved, zigzag, square wave and hexagonal, by numerical simulation and experimental tests for mixing part in micromixer. Simulations were performed in ANSYS CFX with homogeneous two-phase flow model in a porous media. As the result inclined hexagonal micromixer showed the best performance (in comparison with the straight one) exhibiting 44. 24% of improvement which leads to a detection range and LOD of and, respectively. Considering the significant impact of micromixers in microfluidics, the quality of mixing and therefore the accuracy of the devices was improved by simple geometrical modifications.

Objective(s): To determining of sodium NITRITE in susage and compasion with amount of standard and change of NITRITE in the course of time. Methods: For sampling, took action in thirty different time production (P<0.05) from every one of eleven factory products that enter meat products to Semnan Province and samples transferred to laboratory. For determining of NITRITE was used from standard number 923 that has been given by Iran standard office. After the determining of NITRITE concentration in samples was taken action respect estimation of confidence space mean with P<0.05 in total samples and was analyzed meanings with amount of standard. Results: In examination of NITRITE in products gave in susags A 54.5 and 55.16, in B 33 and 26.33, in C 7.9 and 7.73, in D 32.1 and 31.33, in E 23.47 and 19.23, in F 54.9 and 48.77 and in C (Tehran) 36.17 and 25.7, in H 19.3 and 13.57, in L 20.43 and 22.9, in K 39.8 and 34, in M 36.6 and 14.63 milligram in kilogram that amounts of theirs with P<0.05 had very meaning different with amount of standard. In examination A products for determining of time effect amount of NITRITE gave in first, seventh, tenth, fourteenth day in manner 50, 43, 42, 39 and in F products in first, seventh, fourteenth in manner 52, 51, 42 milligram in kilogram. Conclusion: In products of A, D, F, B, E, G, C, H, K, L, M, amount of NITRITE was lower than standard and was not problem in this products. Also with examination one sample of products two factories in different times was distinguished that amount of NITRITE decreases in meat products in the course of time.

Agricultural advancement and population growth have prompted increases in food supplies, and higher crop yields have been made possible through the application of fertilizers. Large quantities of livestock and poultry on farms, along with the accumulation of biomass and agricultural residues, can cause contamination of ground water resources and other water sanitation concerns in both developing and developed countries. Nitrate is mainly used as a fertilizer in agriculture, and because of its high solubility in water, it can create biological problems in the environment. High usage of NITRITE in the food industry as a preservative, flavor enhancer, antioxidant, and color stabilizing agent can cause human exposure to this toxic compound. NITRITE is 10 times as toxic as nitrate in humans. Nitrate is converted to NITRITE and nitrosamine compounds in the human stomach, which can lead to bladder cancer. In this review, sources of nitrate and NITRITE exposure were investigated. Furthermore, the review evaluates standard levels of nitrate and NITRITE in different foods, and acceptable daily doses of these compounds in various countries. Finally, we discuss valid methods of nitrate and NITRITE identification and removal in foods.

New Page 1 A chemiluminescence system is described for the determination of NITRITE ion based on new designs for an ozone generator, liquid-gas separator and chemiluminescence reaction cell. The method is based on the gas-phase chemiluminescence reaction between ozone and nitric oxide, which is generated from the reduction of NITRITE with iodide in sulfuric acid solution. The efficiency of the system was evaluated by investigation of the analytical performance characteristics of the system for NITRITE determination in batch and flow injection procedures. Under optimal conditions, the chemiluminescence response of the system was linear against the NITRITE concentration over the range 1 to 1 ´ 104 ng ml-1 in the batch procedure and 10 to 5 ´ 103 ng ml-1 in the flow injection procedure, with detection limits of 1 and 10 ng ml-1, respectively. The method is highly selective and allows for the determination of NITRITE in the presence of high concentrations of several cationic, anionic and nitrogen containing species. It has been successfully applied to the analysis of NITRITE in natural water and soil extracts.