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A green, rapid, simple and reliable procedure was developed for nitrite determination using silver-miang nanocomposites as colorimetric agents and camera phone as a detector. The crude water extracts of miang (Camellia sinensis var. assamica) were adopted as natural reagents in a rapid one-pot microwave synthesis of the nanocomposites. The extracts’ phytochemical contents were studied and the synthesis conditions were optimized. The yielded nanocomposites were characterized by UV–vis and FT-IR spectroscopies, powder X-ray diffraction, transmission electron microscopy, selected area electron diffraction and thermogravimetry, and proved to be reliable colorimetric agents and selective for nitrite. The underlying reactions were investigated. The linear calibration plots could be established based on the ratiometric R/G parameters over 2.0–10 mg∙L−1 nitrite concentration range with satisfying detection limits (0.12–0.62 mg∙L−1). In practice, the procedure was validated and applied with water and commercialized meat samples. The long storage time of miang (>5 years) was also evaluated, manifesting viability and reliability in views of both the nanocomposites synthesis and the nitrite determination performance.

Dietary nitrate has been shown to increase nitrate/nitrite levels in multiple populations, with potential blood pressure lowering effects. However, there are few reports among hypertensives. We aimed to assess the effect of daily nitrate in subjects with controlled hypertension vs. uncontrolled hypertension. On day 0, hypertensives wore an ambulatory BP monitor (ABPM) for 24 h and fasting blood was taken. Subjects then consumed concentrated beetroot juice (12.9 mmol nitrate) for 14 consecutive days. On day 14 subjects consumed their last nitrate dose after fasting blood was drawn and again had an ABPM for 24 h. According to baseline ABPM, 11 subjects had controlled BP while 8 had uncontrolled BP. There were similar, significant increases in serum nitrate/nitrite in both groups. We observed little change in BP variables among controlled hypertensives. However, there were reductions in BP variables in uncontrolled hypertensives where decreases in nighttime DBP (−6 ± 4.8 mmHg), arterial stiffness (−0.08 ± 0.03 ambulatory arterial stiffness index) and LDL (−0.36 ± 0.42 mmol/L) reached significance (p = 003, 0.05 and 0.046, respectively). Our results support the existing data suggesting an anti-hypertensive effect of nitrate-containing beetroot juice, but only among those with uncontrolled hypertension.

The influence of dietary nitrate (NO3−) supplementation on indices of maximal sprint and intermittent exercise performance is unclear. Purpose To investigate the effects of NO3− supplementation on sprint running performance, and cognitive function and exercise performance during the sport-specific Yo-Yo Intermittent Recovery level 1 test (IR1). Methods In a double-blind, randomized, crossover study, 36 male team-sport players received NO3−-rich (BR; 70 mL·day−1; 6.4 mmol of NO3−), and NO3−-depleted (PL; 70 mL·day−1; 0.04 mmol NO3−) beetroot juice for 5 days. On day 5 of supplementation, subjects completed a series of maximal 20-m sprints followed by the Yo-Yo IR1. Cognitive tasks were completed prior to, during and immediately following the Yo-Yo IR1. Results BR improved sprint split times relative to PL at 20 m (1.2%; BR 3.98 ± 0.18 vs. PL 4.03 ± 0.19 s; P Conclusions Dietary NO3− supplementation enhances maximal sprint and high-intensity intermittent running performance in competitive team sport players. Our findings suggest that NO3− supplementation has the potential to improve performance in single-sprint or multiple-sprint (team) sports.

In order to improve the generation amount of nitrous oxide (N 2 O), the process of nitrite (NO 2 − ) reduction was studied by Fe(II–III) carbonate green rust (GR(CO 3 2− )). The results indicated that 97.1% NO 2 − was degraded, and over 71.3% N 2 O was achieved by the oxidation of GR(CO 3 2− ) to Fe 3 O 4 ; 14.1% N 2 , 4.7% NH 4 + and 3.0% NO 3 − were also formed in the denitrification process; the removal efficiency for total nitrogen (TN) was 89.6%; the optimal reaction condition was NO 2 − 10.71 mM, pH 9.5 and an initial E h (the maximum value of E h reached at the beginning of the process) of −473 mV. The generation of different reduction products was dependent on the initial E h of the reaction system. Based on the adjustment of initial E h , the formation order of reduction products was as follows: N 2 O, N 2 and NH 4 + . Additionally, compared with initial nitrite concentration, pH played a decisive role in the initial E h of the NO 2 − /GR(CO 3 2− ) system. The high amount of N 2 O generated by the adjustment of initial E h provides new insight into the NO 2 − /GR(CO 3 2− ) system.

Background: Through effects on nitric oxide bioavailability, vascular endothelial function is improved after the intake of a high amount of nitrate or L-arginine, but decreased after the intake of a high-fat meal. Therefore, we compared the effects of beetroot powder with or without L-arginine on postprandial brachial artery flow-mediated vasodilation (FMD) after consumption of a high-fat mixed-meal. Methods: Eighteen abdominally obese men completed this randomized, double-blinded, cross-over trial. The study consisted of five test days, each separated by a wash-out period of at least one week. Participants received in random order, a blended meal with a control or nutritional supplement consisting of beetroot powder providing 200 mg nitrate, beetroot with 0.8 g of L-arginine, beetroot with 1.5 g of L-arginine, or 3.0 g of L-arginine. Participants then fasted and 2 h postprandial FMD measurements were performed. Results: No significant differences between meals were observed for postprandial FMD (p = 0.45) levels. However, there was a non-significant trend towards a more beneficial postprandial FMD response with the beetroot-containing meals as compared with meals without beetroot. Conclusion: This trial could not provide evidence for beneficial additive effects of a single dose of beetroot powder combined with L-arginine on postprandial endothelial function in abdominally obese men.

A microfluidic colorimetric system comprising of a colorimetric paper-chip device and a microanalysis cassette is presented for detecting the nitrite concentration in foods. In the proposed system, 1 μl of nitrite sample is dropped into the reaction region of the colorimetric paper-chip device, where its reacts with embedded Griess reagent to produce a pink complex. A color image of the reaction complex is caught using an embedded camera and transmitted to a cell phone within the microanalysis cassette via a WiFi connection. Finally, the images were analyzed by self-written RGB (Red, Green, and Blue) software to evaluate the nitrite concentration. The results acquired for 11 known nitrite solutions ranging from 1 to 100 ppm show that the measured R + G + B intensity is related to the nitrite concentration, and the determination coefficient (R2) are 0.9908 and 0.9948 in the two concentration ranges of 1–50 ppm and 50–100 ppm, respectively. The practical feasibility of the current microfluidic system is indicated by analysis the nitrite concentrations of 24 actual samples. Therefore, the difference between the concentration analysis obtained with the current system differ from those obtained using a conventional TFDA (Taiwan Food and Drug Administration) standard method by no more than 7.3%. Furthermore, the detection limit is just 1 ppm.

Dietary nitrate (NO3−) supplementation has been evidenced to induce an ergogenic effect in endurance and sprint-type exercise, which may be underpinned by enhanced muscle contractility and perfusion, particularly in type II muscle fibers. However, limited data are available to evaluate the ergogenic potential of NO3− supplementation during other exercise modalities that mandate type II fiber recruitment, such as weightlifting exercise (i.e., resistance exercise). In this systematic review, we examine the existing evidence basis for NO3− supplementation to improve muscular power, velocity of contraction, and muscular endurance during weightlifting exercise in healthy adults. We also discuss the potential mechanistic bases for any positive effects of NO3− supplementation on resistance exercise performance. Dialnet, Directory of Open Access Journals, Medline, Pubmed, Scielo, Scopus and SPORT Discus databases were searched for articles using the keywords: nitrate or beetroot and supplement or nut*r or diet and strength or “resistance exercise” or “resistance training” or “muscular power”. Four articles fulfilling the inclusion criteria were identified. Two of the four studies indicated that NO3− supplementation could increase aspects of upper body weightlifting exercise (i.e., bench press) performance (increases in mean power/velocity of contraction/number of repetitions to failure), whereas another study observed an increase in the number of repetitions to failure during lower limb weightlifting exercise (i.e., back squat). Although these preliminary observations are encouraging, further research is required for the ergogenic potential of NO3− supplementation on weightlifting exercise performance to be determined.

In the present work, a combined hurdle approach for fermented meat preservation was investigated. Challenge tests were performed in Chorizo sausage model using the maximum allowed NaNO2 amount (150 mg/kg), a reduced amount (75 mg/kg) and no nitrite, with and without protective cultures inoculation. Cocktail strains of L. monocytogenes and Salmonella spp. were used as indicator strains. In a nitrite reduced sausage model, L. monocytogenes growing trend did not significantly change (p > 0.05) when compared with that containing higher nitrite concentration (150 mg/kg NaNO2). The addition of L. plantarum PSC20 significantly lowered L. monocytogenes growth when compared with control batches without PCS20 (p < 0.05), obtaining 3.84 log cfu/g and 2.62 log cfu/g lower counts in the batches with 150 mg/kg NaNO2 and 75 mg/kg NaNO2 respectively. None of the protective cultures demonstrated in situ antagonistic activity against Salmonella spp. This work pointed out that the reduction of nitrites with the combined use of a protective culture could be a feasible approach to control L. monocytogenes growth in fermented meat foods.

Nitric oxide (NO) facilitates anti-atherosclerotic effects. Vegetables are a major source of dietary nitrate. Experimental data indicates that dietary nitrate can significantly reduce major risk factors for atherosclerosis and subsequent cardiovascular disease (CVD), as nitrate can be metabolized to produce NO via the nitrate-nitrite-NO pathway. The purpose of this study was to prospectively investigate the association between habitual dietary nitrate intakes and the incidence of self-reported CVD-related complications within a representative sample of middle-aged Australian women (1946–1951 cohort of the Australian Longitudinal Study on Women’s Health). Women free from disease at baseline who had completed the food frequency questionnaire data were included. Generalized estimating equations were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) across quartiles for nitrate intakes. Of the 5324 women included for analysis, there were 1951 new cases of CVD-related complications over 15-years of follow-up. Women reporting higher total dietary nitrate intakes (Q4 &gt, 78.2 mg/day) and vegetable nitrate intakes (Q4 &gt, 64.4 mg/day) were 25% and 27% reduced risk of developing CVD-related complications respectively, compared with women reporting low total (Q1 &lt, 45.5 mg/day) and vegetable nitrate intakes (Q1 &lt, 34.8 mg/day). Our findings were consistent with other observational data indicating that dietary nitrate may explain some of the cardiovascular benefits of vegetable consumption.

This investigation assessed the effect of dietary nitrate (NO3−) supplementation, in the form of beetroot juice (BR), on repeat-sprint performance in normoxia and normobaric hypoxia. 12 male team-sport athletes (age 22.3 ± 2.6 y, VO2peak 53.1 ± 8.7 mL.kg−1.min−1) completed three exercise trials involving a 10 min submaximal warm-up and 4 sets of cycling repeat-sprint efforts (RSE; 9 × 4 s) at sea level (CON), or at 3000 m simulated altitude following acute supplementation (140 mL) with BR (HYPBR; 13 mmol NO3−) or NO3–depleted BR placebo (HYPPLA). Peak (PPO) and mean (MPO) power output, plus work decrement were recorded during the RSE task, while oxygen consumption (VO2) was measured during the warm-up. There were no significant differences observed between HYPBR and HYPPLA for PPO or MPO; however, work decrement was reduced in the first RSE set in HYPBR compared with HYPPLA. There was a moderate effect for VO2 to be lower following BR at the end of the 10 min warm-up (ES = 0.50 ± 0.51). Dietary NO3− may not improve repeat-sprint performance in hypoxia but may reduce VO2 during submaximal exercise. Therefore, BR supplementation may be more effective for performance improvement during predominantly aerobic exercise.

Intake of dietary nitrate, such as beetroot juice, has received a lot of attention the past few years because of possible performance-enhancing effects for athletes. This thesis describes various factors important to gain this effect. It shows nitrate-rich vegetables (such as beetroot and spinach) are the most effective sources of nitrate. Research among athletes also shows that high intensity athletes such as football players could benefit from dietary nitrate intake, whereas endurance athletes such as cyclists would not. The thesis concludes that nitrate stored in muscle tissue and could play an important part in providing beneficial effects in sports performance.

It has been reported that low BMI is associated with lower CSF pressure, which then translates into higher translaminar cribrosa pressure gradient, which is a risk factor for glaucoma. Previously, in our epidemiologic studies, we have reported that low BMI was a possible risk factor for POAG. To better understand this association and because POAG is a heterogeneous condition, we previously evaluated the relation between BMI and POAG subtypes based on pattern of visual field loss. We observed that low BMI is more strongly associated with primary open-angle glaucoma where the loss of vision tends to focus on the paracentral region rather than the peripheral vision. Every 10-unit increase in BMI was associated with a 33% lower risk of primary open-angle glaucoma with early paracentral loss, whereas it was not associated with peripheral loss [1, 2]. So we have hypothesized that the paracentral fibers, particularly the inferior, are in the “macular vulnerability zone,” as the fovea lies below the disc, and accompanying blood vessels make more acute arcuate turns, creating shear forces that could compromise local blood flow.

Interest in inorganic nitrate and nitrite has grown substantially over the past decade as research has revealed the role of these anions in enhancing nitric oxide (NO) availability through an oral pathway. Nitrite synthesis in the mouth seems to be an important mechanism to feed the circulatory system with this anion. This is interesting since greater plasma nitrite concentration has been associated with better fitness levels in humans, but this question has not been investigated in relation to salivary nitrite concentration. Additionally, no previous study has investigated the oral nitrate-reducing capacity in regards to peak oxygen uptake (VO2peak) or peak power output (Wpeak) in humans. Thus, the main goal of this study was to investigate whether salivary nitrite and nitrate concentration and the oral nitrate-reducing capacity were associated with VO2peak and Wpeak in healthy humans. Fifty individuals (22 females and 28 males; 38.8 ± 14.3 years/old; BMI = 22.8 ± 3.9) performed a graded exercise test on a cycle ergometer to assess their VO2peak and Wpeak. Unstimulated salivary samples were taken before and 20 min after exercise to measure nitrate/nitrite, pH and lactate. The oral nitrate-reducing capacity was also assessed in 25 subjects before and after exercise. Oral nitrate-reducing capacity was positively associated with Wpeak (rs = 0.64; P = 0.001) and the VO2peak (rs = 0.54; P = 0.005). Similar correlations were found when these variables were analysed after exercise. In addition, a significant decrease in salivary pH (pre: 7.28 ± 0.361; post-exercise: 7.16 ± 0.33; P = 0.003) accompanied by an increase of salivary lactate (pre: 0.17 ± 0.14 mmol/L; post-exercise: 0.48 ± 0.38; P In conclusion, this is the first evidence showing a link between the oral nitrate-reducing capacity and markers of aerobic fitness levels in healthy humans.

Purpose Dietary nitrate (NO3−) has repeatedly been shown to improve endurance and intermittent, high-intensity events in temperate conditions. However, the ergogenic effects of dietary NO3− on intermittent exercise performance in hot conditions have yet to be investigated. Methods In a randomised, counterbalanced, double-blind crossover study, 12 recreationally trained males ingested a nitrate-rich beetroot juice shot (BRJ) (6.2 mmol NO3−) or a nitrate-depleted placebo (PLA) ( 0.05). There was a reduced peak (BRJ: 659 ± 100W vs. PLA: 693 ± 139W; p = 0.056) and mean power (BRJ: 543 ± 29W vs. PLA: 575 ± 38W; p = 0.081) following BRJ compared to PLA in the hot and humid condition, but this was not statistically significant. There was no effect of supplement on total work done irrespective of environmental condition. However, ~ 75% of participants experienced performance decreases following BRJ in the hot and humid environment. No differences were observed between trials for tympanic temperature measured at the conclusion of the exercise trial. Conclusion In conclusion, an acute dose of inorganic dietary NO3− does not improve repeated-sprint performance in either temperate, or hot and humid conditions.

Dietary nitrate may improve exercise tolerance in some healthy and clinical populations. Existing data regarding dietary nitrate in COPD is inconsistent. We conducted a 14d double-blind, randomised, placebo-controlled, crossover trial of daily nitrate-rich beetroot juice (BRJ; 12.9 mmol) versus nitrate-depleted BRJ (PL; 0.5 mmol). At baseline and after each condition, we assessed functional capacity (incremental shuttle walk test; ISWT), ambulatory blood pressure, pulmonary function, quality of life as well as exhaled nitric oxide (eNO), and plasma nitrate/nitrite (NOx). Eight subjects with COPD completed the trial. BRJ supplementation was associated with significantly increased NOx (p .05) and a 14.6% increase in ISWT distance (+56 m, p = .00004) as well as a trend towards increased eNO compared to PL. There was no other differences. Dietary nitrate appears to have ergogenic effect in subjects with mild-moderate COPD. This effect does not appear to be related to altering blood pressure or pulmonary function.

The reaction between diperiodatoargentate(III) (DPA) and folic acid (FA) produced weak chemiluminescence (CL) in acid medium, which was greatly enhanced in the presence of copper nanoclusters (CuNCs). The CL intensity of CuNCs-DPA-FA system increased with the concentration of FA ranging from 0.1 to 10.0 μM. The proposed CL system was applied for the detection of FA in pharmaceutical formulation and human urine samples. Further, the CL signal of CuNCs-DPA-FA system was inhibited by nitrite, and the inhibited CL intensity was proportional to the nitrite concentration in the range of 1.0–80.0 μM. The method was successfully applied to determine nitrite in water, pickled vegetable and sausage samples. A possible CL mechanism was briefly discussed.

The intake of nitrate from vegetables or dietary supplements that contain red beet juice can reduce blood pressure and improve sports performance. This dissertation focused on how nitrate supplementation can be optimised to improve sports performance and the extent to which nitrate supplementation can be used in professional sports. Nitrate-rich vegetables such as red beets, arugula and spinach proved to be the most effective sources of nitrate. Performance improvement following nitrate intake is primarily seen in extremely high-intensity sports, such as repeated sprints, and after multi-day nitrate intake, even among professional athletes. Together with NOC*NSF, we are currently working on sport-specific guidelines for nitrate supplementation to improve the athletic performance of professional athletes.

Increasing consumer concerns of harmful preservatives have intensified consumers’ demand for natural and organic alternatives. In response to this demand, uncured or no- nitrate-or-nitrite-added meat products which utilize celery juice concentrates as an alternative to sodium nitrite, have emerged on the market to replace conventional nitrite sources. The objective of this study was to evaluate the effect of celery juice pH for the impact of nitrite on L. monocytogenes growth. In addition, equal concentrations of nitrite in celery juice and conventional nitrite were evaluated to determine the impact of nitrite concentration from these sources on L. monocytogenes growth. These objectives were assessed using both a broth and ham system. Celery juice (CJ) was less effective than the conventional nitrite in the broth study at 100 ppm nitrite concentration but in the ham experiment the CJ treatments at both 100 and 200 ppm resulted in similar growth of L. monocytogenes (p>0.05) compared to their counterparts 100 and 200 ppm sodium nitrite. Adjusting the pH of the celery juice proved to be more effective at suppressing L. monocytogenes growth at 200 ppm than 100 ppm in the ham. No differences in growth (p>0.05) were found between the unadjusted 100

It is known that high blood pressure variability (BPV) in acute ischemic stroke is associated with adverse outcomes, yet there are no therapeutic treatments to reduce BPV. Studies have found increasing nitric oxide (NO) bioavailability improves neurological function following stroke, but whether dietary nitrate supplementation could reduce BPV remains unknown. We investigated the effects of dietary nitrate supplementation on heart rate (HR), blood pressure (BP), and beat-to-beat BPV using wireless telemetry in a rat model of distal middle cerebral artery occlusion. Blood pressure variability was characterized by spectral power analysis in the low frequency (LF; 0.2–0.6 Hz) range prestroke and during the 7 days poststroke in a control group ( n = 8) and a treatment group ( n = 8, 183 mg/l sodium nitrate in drinking water). Dietary nitrate supplementation moderately reduced systolic BPV in the LF range by ~11% compared with the control group ( P = 0.03), while resting BP and HR were not different between the two groups ( P = 0.28 and 0.33, respectively). Despite systolic BPV being reduced with dietary nitrate, we found no difference in infarct volumes between the treatment and the control groups (1.59 vs. 1.62 mm3, P = 0.86). These findings indicate that dietary nitrate supplementation is effective in reducing systolic BPV following stroke without affecting absolute BP. In light of mounting evidence linking increased BPV with poor stroke patient outcome, our data support the role of dietary nitrate as an adjunct treatment following ischemic stroke. NEW & NOTEWORTHY Using a rat model of stroke, we found that dietary nitrate supplementation reduced low frequency blood pressure fluctuations following stroke without affecting absolute blood pressure values. Since blood pressure fluctuations are associated with poor clinical outcome in stroke patients, our findings indicate that dietary nitrate could be an effective strategy for reducing blood pressure fluctuations, which could help reduce stroke severity and improve patient recovery.

Evidence suggests dietary nitrate supplementation enhances low-frequency (≤20 Hz) involuntary, but not voluntary, forces in unfatigued human muscle. We investigated the hypotheses that nitrate supplementation would also attenuate low-frequency fatigue and the loss of explosive voluntary forces in fatigued conditions.In a counterbalanced double-blinded order, 17 male participants completed two experimental trials after 7 d of dietary supplementation with either nitrate-rich (NIT) or nitrate-depleted (PLA) beetroot juice. Each trial consisted of measuring isometric knee extension forces during a series of explosive maximal voluntary contractions (MVC) and involuntary tetanic contractions (at 10, 20 50, and 100 Hz) in unfatigued conditions, followed by a fatigue protocol of 60 MVC and a repeat of the tetanic contractions immediately after the 60 MVC.In unfatigued conditions, there was no effect of NIT on any of the measured dependent variables, including maximal voluntary force, explosive impulse, and tetanic peak forces or peak rate of force developments at any frequency. In contrast, the percentage decline in explosive voluntary impulse from the first to the last 6 MVC in the fatigue protocol was lower in NIT (51.1% ± 13.9%) than in PLA (57.3% ± 12.4%; P = 0.039; d = 0.51). Furthermore, low-frequency fatigue determined via the percentage decline in the 20/50-Hz ratio was attenuated in NIT for tetanic peak force (NIT: 12.3% ± 12.0% vs PLA: 17.0% ± 10.1%; P = 0.110; d = 0.46) and tetanic peak rate force development (NIT: 12.3% ± 10.4% vs PLA: 20.3% ± 9.5%; P = 0.011; d = 0.83).Nitrate supplementation reduced the decline in explosive voluntary forces during a fatiguing protocol and attenuated low-frequency fatigue, likely due to reduced disruption of excitation-contraction coupling. However, contrary to previous findings, nitrate supplementation had no effect on contractile performance in unfatigued conditions.

Dietary nitrate supplementation has positive effects on mitochondrial and muscle contractile efficiency during large muscle mass exercise in humans and on skeletal muscle blood flow (Q̇) in rats. However, concurrent measurement of these effects has not been performed in humans. Therefore, we assessed the influence of nitrate supplementation on Q̇ and muscle oxygenation characteristics during moderate- (40 %peak) and severe-intensity(85% peak) handgrip exercise in a randomized, double-blind, crossover design. Nine healthy men (age: 25 ± 2 yr) completed four constant-power exercise tests (2/intensity) randomly assigned to condition [nitrate-rich (nitrate) or nitrate-poor (placebo) beetroot supplementation] and intensity (40 or 85% peak). Resting mean arterial pressure was lower after nitrate compared with placebo (84 ± 4 vs. 89 ± 4 mmHg, P < 0.01). All subjects were able to sustain 10 min of exercise at 40% peak in both conditions. Nitrate had no effect on exercise tolerance during 85% peak (nitrate: 358 ± 29; placebo: 341 ± 34 s; P = 0.3). Brachial artery Q̇ was not different after nitrate at rest or any time during exercise. Deoxygenated [hemoglobin + myoglobin] was not different for 40% peak ( P > 0.05) but was elevated throughout 85% peak ( P < 0.05) after nitrate. The metabolic cost (V̇o2) was not different at the end of exercise; however, the V̇o2 primary amplitude at the onset of exercise was elevated after nitrate for the 85% peak work rate (96 ± 20 vs. 72 ± 12 ml/min, P < 0.05) and had a faster response. These findings suggest that an acute dose of nitrate reduces resting blood pressure and speeds V̇o2 kinetics in young adults but does not augment Q̇ or reduce steady-state V̇o2 during small muscle mass handgrip exercise. NEW & NOTEWORTHY We show that acute dietary nitrate supplementation via beetroot juice increases the amplitude and speed of local muscle V̇o2 on kinetics parameters during severe- but not moderate-intensity handgrip exercise. These changes were found in the absence of an increased blood flow response, suggesting that the increased V̇o2 was attained via improvements in fractional O2 extraction and/or spatial distribution of blood flow within the exercising muscle.

Intro: Hypertension is a prominent risk factor for cardiovascular disease and arterial stiffness is a related predictor of both mortality and longitudinal onset of hypertension in normotensive individuals. Both vascular compliance and blood pressure have been shown to improve following dietary nitrate supplementation in some healthy and diseased individuals. Dietary nitrate supplementation increases plasma nitrite and may, therefore, enhance bioavailability of endothelium derived nitric oxide. Chronic increased flow mediated dilation (FMD) and reduction of pulse wave velocity (PWV) reduce a person’s long-term risk for developing endothelial dysfunction, atherosclerosis and hypertension. Hypothesis: We hypothesized that an acute dose of dietary nitrate would improve FMD, decrease PWV and reduce central blood pressure (cBP) in healthy, young females. Methods: Seven healthy, young (21 ± 2 years) females participated in a randomized, double blind, placebo controlled, crossover protocol. Participants had endothelial function measured via FMD, arterial stiffness via PWV and applanation tonometry, and cBP was determined non-invasively using pulse wave analysis following a 12-hour fasting period and 48-hour NIH approved low nitrate diet. Baseline values were measured the day before each treatment visit (placebo or nitrate-rich, separated by a 1-week washout period). Participants consumed either a placebo or nitrate-rich supplement (negligible and 6.2 mmol nitrate, respectively) 2 hours prior to their laboratory visit. Upon arrival, blood was drawn and participants assumed a supine position for 15 minutes. Then brachial artery FMD was assessed via high definition ultrasound imaging following 5 minutes of proximal forearm occlusion, followed by PWV and central blood pressure measurements. Results: Plasma nitrite was elevated following consumption of the nitrate rich supplement compared to placebo (26.33 ± 15.76 and 1.18 ± 0.96 arbitrary units, respectively; p Conclusion: While a single dose of dietary nitrate does increase plasma nitrite, supplementation has minimal effects on FMD, PWV and cBP in young healthy females. Future research should examine longer duration supplementation protocols as well as the changes in vascular health of patients with known disease such as hypertension or peripheral artery disease.

The aims of the present study were to explore whether a long-term intervention with dietary nitrate [(NOA subsample of participants in our double-blind, randomized, factorial-design intervention (VaSera) trial of active beetroot juice as a nitrate source (≤11.2 mmol) or placebo (nitrate depleted) beetroot juice, and either ≤50 mg spironolactone or ≤16 mg doxazosin (control), had transthoracic cardiac ultrasounds at baseline (n = 105), and at 3 months and 6 months (n = 87) after the start of the intervention. Analysis was by modified intent-to-treat.Nitrate-containing juice (n = 40) decreased left ventricular (LV) end-diastolic volume {-6.3 [95% confidence interval (CI) -11.1, -1.6] ml} and end-systolic volume [-3.2 (95% CI -5.9, -0.5) ml], and increased end-diastolic mass/volume ratio [+0.04 (95% CI 0.00, 0.07)], relative to placebo juice (n = 47). Spironolactone (n = 44) reduced relative wall thickness compared with doxazosin (n = 43) [-0.01 (95% CI -0.02, -0.00)]. Although spironolactone reduced LV mass index relative to baseline [-1.48 (95% CI -2.08, -0.88) g mSix months' dietary nitrate decreased LV volumes ~5%, representing new, sustained, BP-independent benefits on cardiac structure, extending mechanisms characterized in preclinical models of heart failure. Spironolactone's effects on cardiac remodelling and systolic-diastolic function, although confirmatory, were independent of BP.

This study was carried out to investigate the effect of different nitrite concentrations on the sensory parameters of roast beef including color, flavor, juiciness, texture and overall acceptability. Four roast beef batches were formulated; the first three treatments were with nitrite concentrations of 0.006%, 0.012% and 0.018% and stored at abused chilling temperature (12°C), while the fourth one was a control treatment with 0.026% nitrite and storage at 4°C. Results showed that increasing nitrite concentration from 0.006% to 0.026% enhanced the shelf life of roast beef stored for 7 days without affecting the sensory characteristics whether at 12°C or 4°C since there were no significant differences (P > 0.05) between all treatments regarding color, flavor, juiciness, texture and overall acceptability. These results could direct us to use high nitrite concentration to protect this product and elongate its shelf life without affecting its preference parameters.

This study was carried out to investigate the effect of nitrite concentration, and abused chilling temperature against proper chilling temperature on the chemical, microbiological and shelf life of roast beef stored at 4°C and 12°C. Three roast beef treatments were formulated to investigate the effect of nitrite concentration (0.006%, 0.012% and 0.018%) and abused chilling temperature (12°C) against control treatment (0.026% nitrite and storage at 4°C) on the chemical, microbiological and shelf life. Results showed that roast beef containing 0.026% nitrite and stored at 4°C for 25 days had the lowest thiobarbituric acid (TBA) value while the highest TBA values were in the treatment containing 0.006% added nitrite, stored at 12°C. The aerobic plate count, Enterobacteriaceae, lactic acid bacteria (LAB), and spore former count were increased throughout the storage period which was lower in 0.026% and 0.018% containing nitrite treatments while higher in other two treatments. The lowest percentage of nitrite losses during storage was in the samples having 0.026% added nitrite to roast beef. The results emphasized the risk of abused temperature and the importance of keeping this product under efficient and consistent refrigeration during storage and the use of high nitrite concentration to protect it and elongate its shelf life.

A simple and sensitive photoelectrochemical sensor based on the bismuth vanadate (BiVO4) photoanode coupled to visible light excitation was developed for nitrite detection. The BiVO4 was prepared by hydrothermal methods and used as photoelectroactive sensor. Photoexcitation with visible light allows nitrite anions to act as highly efficient hole scavenger at low potential. The photocurrent response increases linearly with nitrite concentration in the solution. The proposed device operates in the range of detection (2.5 to 100.0 μmol L–1), with limit of detection (1.5 μmol L–1), and with good reproducibility (4.1%) for nitrite analysis. Keywords: Bismuth vanadate, Photoelectrochemical sensor, Nitrite, Hole scavenger

Deli-style turkey breast cured with pre-converted celery juice powder (CP) or sodium nitrite (SN) was manufactured with ingoing SN concentrations or equivalent of 0, 50, 100, 150, and 200 ppm. Cured and total meat pigment, salt, and water activity were measured on d 0; color, pH, and residual nitrite were measured on d 0, 7, 14, 21, 28, 35, and 42. Untrained panelists evaluated sensory traits of 50, 100, 150, and 200 ppm products. The interaction of nitrite concentration and source affected (P≤0.05) b*, pH, and residual nitrite values. Less ingoing nitrite and increased storage resulted in less (P≤0.05) residual nitrite in products. Sensory results suggested products made with 200 ppm nitrite from CP were less acceptable. Overall, CP and SN products were similar for several traits, but this study suggests that the inclusion of ingoing nitrite from CP may be limited to 100 ppm nitrite (0.46% addition) for acceptable deli-style turkey breast.

This paper describes a simple, sensitive, and selective spectrofluorimetric method to determine trace amount of nitrite in food products using 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate (DAF-FM DA) as a fluorescent probe. The reaction of DAF-FM DA with nitrite in acidic medium resulted in triazolofluorescein (DAF-FM T), a highly fluorescent reagent in neutral medium. The fluorescence enhancement was proportional to nitrite concentration in the range of 5.0 × 10−8 to 1.5 × 10−6 mol L−1 with a detection limit of 3.3 × 10−8 mol L−1 (S/N = 3). The proposed method has been applied to the determination of nitrite in real food samples, with relative standard deviation (RSD) (n = 6) less than 5.1 % and recoveries in the range of 86.4 ~ 102.9 %.

Obstructive sleep apnoea syndrome (OSAS) is a consequence of repetitive oropharyngeal airway narrowing/closure during sleep resulting in chronic intermittent hypoxaemia [1]. OSAS is regarded as an independent risk factor for hypertension (HTN) development [2] and is associated with decreased cerebral blood flow [3], leading to daytime neuropsychological sequelae [1]. Blood pressure (BP) follows a circadian rhythm termed dipping and the absence of nocturnal BP dipping is associated with target-organ damage, cerebrovascular disease, myocardial remodelling and increased cardiovascular events/mortality [4]. Abnormal BP in OSAS typically manifests as reduced nocturnal BP dipping [5]. Although continuous positive airway pressure therapy (CPAP) represents the current gold standard treatment of OSAS, its antihyper- tensive effect is limited

Beef is a nutritious food to consume due to its nutrient content that needed by human body. The demand for beef increases in certain times, such as in religion event or in the holiday. Special treatment is needed for the slaughter time to ready to consume beef, such as freezing or refrigerating. This research aimed to identify the quality of fresh beef as well as frozen beef in the traditional market and frozen beef in supermarket regarding its content of micronutrient (iron and zinc), preservatives (nitrate), and another dangerous additional food (formaldehyde) in cub roll, upper thighs, and lower thighs of beef. This was a cross-sectional and laboratory observational designed research. The result showed that iron, zinc, and nitrite concentration on fresh beef and frozen beef in traditional market and supermarket on any side of the beef sample was not significantly different (p>0.05). Nitrite concentration was within the permitted level. All beef samples also had not contain formaldehyde.