Search Results (195)

Aquaponics is a resource-efficient agricultural system, yet its overall productivity is frequently constrained by micro- and macronutrient deficiencies, particularly iron (Fe) and potassium (K). Currently, the efficacy of combined dietary Fe and K supplementation in optimizing nutrient management in these systems remains unclear. Therefore, a 60-day feeding trial was conducted to evaluate the effects of four dietary Fe and K levels—CK (basal diet without added Fe or K), T1 (Fe 0.1 g/kg + K 2.5 g/kg), T2 (Fe 0.2 g/kg + K 5.0 g/kg), and T3 (Fe 0.3 g/kg + K 7.5 g/kg)—on the growth and quality of lettuce (Lactuca sativa) and the physiological responses of crucian carp (Carassius auratus). The results demonstrated that the T2 treatment was suitable for enhancing system productivity. Compared with the CK group, the lettuce plant height, biomass, and net photosynthetic rate in the T2 group exhibited marked increases of 25.3%, 16.0%, and 26.4%, respectively. Furthermore, the vitamin C content increased by 52.2%, while the nitrate content notably declined by 32.2%. Plant nutrient analysis revealed that the combined Fe and K supplementation markedly promoted the foliar uptake of P, Mn, and Zn (peaking in the T2 group), whereas Cu and S contents increased linearly with the supplementation dose, reaching its maximum in the T3 group. Regarding fish health, the weight gain rate (WGR) of crucian carp in the T2 group peaked at 41.0%, and the feed conversion ratio (FCR) improved to 1.76. Additionally, the dietary supplementation maintained the stability of water quality parameters of the recirculating system. These findings indicate that a combined dietary inclusion of 0.2 g/kg Fe and 5.0 g/kg K can simultaneously enhance the yield and quality of both plants and fish. This approach provides a novel optimization strategy for mitigating acute water quality shocks, while also highlighting the inherent boundaries of competitive ion antagonism in aquaponic nutrient management. Full article

Background: The purpose of this study was to examine the effects of acute dietary nitrate (NO₃⁻) and caffeine (CAF) supplementation on end power (EP) and work performed above EP (WEP) in trained male cyclists during a 3 min all-out test (3MT) on a cycle ergometer. Methods: Fifteen healthy, trained male cyclists (28.5 ± 5.3 years, 79.2 ± 9.1 kg, VO₂peak 55.2 ± 5.6 mL·kg⁻¹·min⁻¹) completed four exercise trials in a randomized, double-blind, placebo-controlled, crossover study design separated by 3–7 days. The four experimental conditions were placebo beverage (nitrate-depleted) + placebo capsule, nitrate-rich beetroot juice + placebo capsule (BR), placebo beverage + caffeine capsule (CAF), and nitrate-rich beetroot juice + caffeine capsule (BR + CAF). Participants consumed nitrate-rich beetroot juice (~13 mmol NO₃⁻) or nitrate-depleted placebo three hours before exercise, and caffeine (5 mg∙kg⁻¹) or maltodextrin placebo one hour before testing. EP and WEP were determined from the 3MT. Secondary outcomes included peak and mean power output. Data were analyzed using a repeated-measures ANOVA with repeated measures on condition. A p-value of 0.05 was used to determine statistical significance. Effect size was evaluated using partial eta squared. Results: No significant effect of condition was observed for EP (p = 0.401, ηp² = 0.056), WEP (p = 0.580, ηp² = 0.048), peak power (p = 0.642, ηp² = 0.046), mean power (p = 0.212, ηp² = 0.108), or total work (p = 0.217, ηp² = 0.107). Conclusions: No statistically significant differences between conditions were detected under the conditions of the present study. Full article

Manganese (Mn) is an essential trace element crucial for antioxidant defense, metabolism, and neuronal function, yet both deficiency and excess may induce oxidative stress and organ-specific damage. This study investigated the effects of dietary manganese exclusion and replacement of standard MnCO₃ with Mn₂O₃ nanoparticles on redox status and oxidative damage in rats. Twenty-four male Wistar rats were divided into three groups: control (K) receiving 65 mg/kg Mn as MnCO₃, manganese-deficient (B), and nanoparticle-supplemented (N) receiving 65 mg/kg Mn as Mn₂O₃ nanoparticles. After 12 weeks, tissues were analyzed for oxidative stress markers and antioxidant enzyme activities. Manganese deficiency resulted in decreased plasma SOD activity, increased lipid peroxidation, and severe oxidative–nitrosative damage in the brain and jejunum, despite hepatic compensatory mechanisms. Mn₂O₃ nanoparticle supplementation enhanced hepatic and renal antioxidant capacity, reducing oxidative damage in these organs. However, nanoparticles induced pronounced neurotoxicity, characterized by GSH depletion, elevated DNA damage (8-OHdG), protein nitration (3-NT), and caspase activation in brain tissue. These findings demonstrate that while Mn₂O₃ nanoparticles offer improved bioavailability and hepatorenal benefits, they pose significant neurotoxic risks, necessitating caution in dietary supplementation strategies. Full article

Background: Beets are enriched in bioactive compounds with beneficial effects on cardiovascular function. Nitrate is a precursor for nitric oxide synthesis, exhibiting an effect on cardiomyocytes and myocardial ischemia/reperfusion, improving endothelial function and reducing arterial stiffness. Betanin, saponins and phenolic compounds, other beet compounds, can limit the generation of reactive oxygen species and modulate gene expression. However, it has been a challenge to develop beetroot formulations for the oral administration of these compounds while preserving pleasant sensory characteristics. Objective: The objective of this study was to develop an innovative dairy–beetroot powder drink, microencapsulated in polysaccharides, i.e., maltodextrin, cassava starch or a combination of both, that could be easily reconstituted. Key Results: The microencapsulated formulation following freeze-drying displayed low water activity (<0.30) and high solubility (>90%), with rapid dispersion in aqueous medium. Fourier transform infrared spectroscopy confirmed the preservation of functional groups from the dairy base and sugar beetroots. Thermogravimetry analyses pointed out a slight increase in thermal stability for the powder formulation. The microencapsulation efficiency of betalains reached 81% in the powder formulation that combined cassava starch and maltodextrin as encapsulation agents. The novel dairy–beetroot powder drink can be stored at room temperature, ensuring microbiological safety and preserving good sensory acceptance. Conclusions: Dairy–beetroot powder microcapsules emerge as an efficient food strategy to provide bioaccessible dietary nitrate and antioxidant compounds, overcoming flavor and stability limitations but still aiding in terms of its vascular and hemodynamic-protective effects. Full article

Nitrate-rich vegetables are increasingly recognised as a key subgroup of phytochemical-dense foods that have significant potential for preventing and managing chronic diseases. Although dietary nitrates were historically approached with caution due to concerns about nitrosamine formation, contemporary evidence highlights their beneficial effects on vascular, metabolic and cognitive functions. Ageing is characterised by endothelial dysfunction, impaired nitric oxide (NO) synthesis and increased oxidative stress, which elevates cardiovascular risk. In this context, nitrate-rich vegetables offer a natural way to restore NO bioavailability and support cardiometabolic health. This narrative review provides an integrative overview of nitrate-rich vegetables as sources of bioactive phytochemicals with therapeutic relevance. We summarise the biochemical pathways of nitrate and nitrite metabolism, including the enterosalivary nitrate–nitrite–NO cycle, the role of oral microbiota, and red blood cell-mediated nitrite reduction. Particular emphasis is placed on NOS-independent NO production, which becomes increasingly important with age, and on the synergistic interactions between dietary nitrates and other phytochemicals such as polyphenols, vitamin C, flavonoids and betalains. These compounds enhance NO stability, reduce oxidative stress, modulate inflammatory signalling and support mitochondrial function, thereby amplifying the health benefits of nitrate-rich vegetables. Beetroot, with its high nitrate content and distinctive antioxidant profile, is highlighted as a prime example. Clinical and mechanistic studies suggest that nitrate-rich vegetables may lower blood pressure, improve endothelial function and cerebral perfusion, enhance cognitive performance and muscle oxygenation, and increase exercise efficiency, particularly in older adults. Additional benefits include anti-inflammatory effects, modulation of platelet function and improvements in metabolic parameters, all of which are relevant to the prevention of chronic diseases such as hypertension, type 2 diabetes and atherosclerosis. While dietary nitrate is generally considered low-risk for healthy adults, caution is warranted in susceptible populations, such as infants and individuals with impaired renal function. Finally, significant research gaps remain, including the need for long-term, well-controlled trials and personalised strategies that account for variability in microbiota composition and nitrate metabolism between individuals. Full article

This research explored how dietary supplementation of calcium nitrate influences methane emissions, nitrogen excretion, ruminal fermentation parameters, and microbiota in Liuyang black goats. A total of twelve male goats from this breed were divided into two groups: one serving as a control group (CON), while the other received a treatment of 3% calcium nitrate (CAL). The research was conducted over a period of 40 days and comprised two separate trial phases. A 10-day adaptation period and a 5-day sampling period (days 11–15) for each stage. Results showed that incorporating calcium nitrate significantly reduced the emissions of methane (CH₄) (p < 0.05) and carbon dioxide (CO₂) (p < 0.05). Moreover, the use of calcium nitrate modified the trends in ruminal fermentation, resulting in an increase in pH (p < 0.05). Moreover, the ratio of acetate to propionate (A:P) was notably reduced in the CAL group (p < 0.05), indicating a shift toward enhanced production of propionate. At the microbial level, an increased presence of Bacteroidota and Prevotella was observed in the CAL group (p < 0.05). In contrast, the CON group exhibited elevated levels of Firmicutes and Methanobrevibacter (p < 0.05). This finding suggests that calcium nitrate plays a significant role in reducing methane emissions and also affects the fermentation processes in the rumen along with the microbiota of Liuyang black goats. Further research is needed to examine the long-term implications of calcium nitrate supplementation on the health and productivity of these goats. Full article

This study presents a comparative evaluation of four drying methods for carrot, red beet, and pumpkin pomace to produce natural functional food ingredients. The work addresses the valorization of 35–45% vegetable processing waste—a rich source of bioactive compounds—aligning with circular bioeconomy principles and Kazakhstan’s goals for deep processing of agricultural raw materials. The compared methods were convective drying (CD), ultrasound pretreatment + convective drying (US + CD), vacuum-microwave drying (VMD), and ultrasound pretreatment + vacuum-microwave drying (US + VMD). Drying kinetics, water activity, physicochemical and functional properties of powders, retention of bioactive compounds, color characteristics, thermal stability, and sensory attributes were assessed. Kinetics were fitted using Midilli et al., Page, and Weibull models. US + VMD provided the highest drying acceleration (6–11 times faster than CD), reaching final moisture of 5.1–5.9%, water activity a_w 0.27–0.31 in 80–170 min, and bioactive compound retention of 90–95% (carotenoids 92–95%, betalains 90–94%). It also delivered superior flowability (Carr’s index 22.5–30.4%), dispersibility (80–88% in 30 s), and thermal stability (75–85% at 200 °C). Acceleration varied by raw material: maximum for beet (up to 11×) due to soluble sugars and nitrates, minimum for pumpkin (5.5–8×) due to dietary fibers and pectins, and intermediate for carrot (6–9×) influenced by carotenoids’ dielectric properties. The results highlight US + VMD’s strong potential for producing functional powders to replace synthetic additives in food systems. Effective method selection and parameter optimization require consideration of raw material type and rheological characteristics. Full article

Background: Low estrogen levels during menopause reduce nitric oxide (NO) production, contributing to decline in skeletal muscle quality and function. Although acute and short-term dietary nitrate supplementation has demonstrated promising effects, long-term benefits, particularly on muscle quality in postmenopausal women, are not well established. Objectives: The objective was to investigate the effects of long-term (12-week) nitrate-rich beetroot extract supplementation on morphological and functional muscle quality, rate of force development (RFD), maximal strength, and circulating nitrate/nitrite concentrations in postmenopausal women. Methods: In a randomized, double-blind, placebo-controlled design, 20 postmenopausal women (21 years ± 7 since menopause) consumed 20 g/day of a nitrate-rich beetroot extract (BET; 548 mg nitrate/day) or a nitrate-depleted beetroot extract (PLA; 43 mg nitrate/day) for 12 weeks. Outcome measures, including muscle quality (functional via muscle strength/thickness ratio; morphological via ultrasound echo intensity), RFD, maximal voluntary isometric contraction (MVIC), and serum nitrate/nitrite levels, were evaluated at baseline, 8 weeks, and 12 weeks. Results: BET significantly increased serum nitrate (0.005) and nitrite (0.022) levels compared to PLA at both week 8 and week 12. Morphological muscle quality also improved significantly in the BET group (interaction effect, p = 0.014). Early-phase rate of force development (RFD) increased between 30 and 100 ms, whereas late-phase RFD increased between 100 and 200 ms. RFD_peak also improved by week 8, and these gains were maintained through week 12 (interaction effect, p < 0.05). Although there was no significant difference between groups for functional muscle quality, MVIC increased at week 12 in the BET group, but no significant Time × Group interaction was observed. Conclusions: Twelve weeks of nitrate-rich beetroot extract supplementation improved morphological muscle quality and RFD, suggesting potential clinical relevance for preventing structural and neuromuscular function decline in postmenopausal women. This study was registered with ReBEC (RBR-87qh649) and approved on 8 October 2024. Full article

Inorganic nitrate (NO₃⁻) has demonstrated therapeutic efficacy in several populations characterised by cardiovascular risk. However, it is unknown whether increasing nitric oxide (NO) bioavailability affects vascular and cardiovascular responses in men with androgenic–anabolic steroid (AAS) abuse. Objective: To investigate the effects of dietary NO₃⁻ on cardiovascular, autonomic, and strength performance in men with AAS abuse. Methods: In this double-blind, randomised, placebo-controlled crossover trial, participants consumed beetroot juice (12.8 mmol [800 mg] NO₃⁻) or a placebo (0.3 mmol NO₃⁻). After two hours, assessments included saliva collection, endothelial function, heart rate, and systolic (SBP) and diastolic (DBP) blood pressure at rest, during, and after an isometric handgrip test. Results: Thirteen resistance-trained males [mean (standard deviation) age: 31 (9) y; body mass index (BMI): 30 (4) kg/m²; SBP: 132 (3) mmHg; DBP: 70 (2) mmHg] completed the protocol. NO₃⁻-rich juice significantly increased salivary NO₃⁻ (40.6 μM, p < 0.001) and nitrite (NO₂⁻) (3.1 μM, p = 0.002) versus placebo. Flow-mediated dilation was greater with NO₃⁻ both at pre-exercise (2.37%, p = 0.02) and post-exercise (2.57%, p = 0.01). No between-group differences were observed in isometric strength (0.02 kgf, p = 0.99) or systolic/diastolic blood pressure across conditions. Conclusions: Dietary NO₃⁻ enhanced salivary NO₂⁻ and NO₃⁻ concentrations and modestly improved endothelial function but did not reduce the elevated blood pressure or alter cardiac autonomic responses associated with AAS abuse. Full article

The objective of this study was to investigate the effect of nitrate (NO₃⁻) supplementation on exercise performance in multiple sets of bench press (BP) and leg press (LP) at 80% of one-repetition maximum (1RM), to determine whether it would be beneficial towards the number of repetitions to failure (RTF). A total of 18 trained male subjects (25 ± 3 years old) completed two sessions of repeated number of maximum repetition (NMR) tests in BP and LP to assess RTF, power output, heart rate (HR), rating of perceived exertion (RPE) 2 h after NO₃⁻ or placebo intake. Comparisons between dependent variables were conducted using a two-factor analysis of variance (ANOVA) with repeated measures, examining the factors of condition and sets. The results for RTF showed only a main effect of set for BP and LP. No significant differences were found between conditions for total RTF. Our results showed that the NO₃⁻ supplementation had no significant effect on RTF, mean power, peak power, HR, and RPE when compared to placebo conditions. Results demonstrated that for physically active male individuals with experience in strength training, NO₃⁻ supplementation did not affect strength endurance performance. Full article

Background: Dextran sodium sulfate (DSS)-induced colitis serves as a preclinical model for studying gut dysbiosis and inflammation relevant to inflammatory bowel disease (IBD) and its long-term complication of colorectal cancer (CRC). Beetroot (Beta vulgaris L.) extract, rich in betalains, polyphenols, and nitrates, exhibits antioxidant and anti-inflammatory properties. This study investigated beetroot extract’s effects on gut microbiota composition and predicted functional pathways in DSS-induced colitis. Methods: Male BALB/c mice were divided into four groups: control (water), DSS-only, beetroot 250 mg/kg + DSS, and beetroot 500 mg/kg + DSS. Beetroot extract was administered orally for 14 days prior to and during DSS exposure. Gut microbial profiles were analyzed using 16S rRNA sequencing, while microbial diversity, community structure, and predicted metabolic functions were evaluated using Shannon, Chao1, PCoA, PERMANOVA, and PICRUSt2 analyses. Results: DSS administration significantly reduced body weight, microbial diversity, and Bacteroidota abundance, while increasing Proteobacteria and Desulfobacterota—a classic colitis-associated dysbiosis signature. Beetroot supplementation restored body weight and microbial balance in a dose-dependent manner, with the 500 mg/kg group showing near-complete normalization of the microbiota. Functional predictions revealed the upregulation of short-chain fatty acid (SCFA) biosynthesis, glutathione metabolism, and amino acid pathways, and suppression of lipopolysaccharide biosynthesis. Identified phytochemicals, including betanin, ferulic acid, and rutin, were associated with antioxidant and prebiotic activities that support microbial restoration. Conclusions: Beetroot extract mitigates DSS-induced gut dysbiosis and inflammation by enhancing microbial diversity, restoring SCFA-associated taxa, and promoting anti-inflammatory and antioxidant pathways. These findings highlight beetroot as a promising natural dietary intervention for colitis and microbiome-associated intestinal disorders. Full article

The importance of micronutrient status in human food choice remains a fundamental issue needing further investigation. The objectives of the present paper are to present and discuss historic and current research together with a general model incorporating this interaction and to suggest future research to address the questions this poses. By definition, essential nutrients must be consumed in sufficient amounts to meet an individual’s requirements. While data indicate that complex neuroendocrine mechanisms provide negative-feedback control of energy and protein intake to support homeostasis, corresponding mechanisms controlling micronutrient intake are less well studied. In some contexts, they are explicitly assumed to be absent, specifically for models evaluating safety and risks of deficiencies. However, it may be hypothesized that for at least some micronutrients, mechanisms exist that aid attainment of requirements by altering preference for micronutrient-rich foods so as to increase ingestion of foods containing them, similar to how being thirsty increases the appeal of watermelon compared with dry food. If this hypothesis is correct, it may hold important implications for understanding the types and quantities of foods ingested. Greater appeal in foods richer in essential nutrients may reduce the risk of malnutrition. However, by extension, it may be posited that the use of supplements could confound the most healthful food choices. For example, obtaining vitamin C from supplements or fortified foods could then causally reduce the dietary intake of vegetables and fruits by reducing the appeal of these foods. The unintended consequence may be a lower intake of fiber, nitrate, and phytochemicals, food constituents that may contribute to health without being essential nutrients themselves. This hypothesis can and should be tested empirically, for example, through randomized placebo-controlled supplementation trials. If clear causal effects are documented, clinical and public health guidance will require critical evaluation and possible modification. Full article

This study investigated the dietary effects of cerium (ammonium ceric nitrate, Ce (NH₄)₂(NO₃)₆) on the growth, serum antioxidant, intestinal digestive enzyme activity, tissue morphology and microbiota of Micropterus salmoides. Seven diets were designed with cerium supplementation of 0 (CON), 10 (Ce10), 20 (Ce20), 40 (Ce40), 60 (Ce60), 80 (Ce80) and 120 mg/kg (Ce120), respectively. Largemouth bass juveniles (initial weight of 16.89 ± 0.04 g) were fed with the above diets for 56 days. Compared with the control group, the weight gain of the Ce40 group increased by 14.4% and the feed conversion ratio decreased by 0.13 (p < 0.05). The Ce60, Ce80 and Ce120 groups showed significantly higher superoxide dismutase activity and lower malondialdehyde concentration compared with the control group (p < 0.05). Protease activity in the Ce20 and Ce40 groups and amylase activity in the Ce40 group were markedly elevated relative to the control group (p < 0.05). The proportion of Firmicutes was increased and the proportion of Proteobacteria was decreased by the addition of 10 mg/kg and 40 mg/kg Ce (Ce10 and Ce40 groups). In summary, dietary cerium supplementation can promote the growth, intestinal digestive enzyme activity, and positive modulation of the intestinal microbial flora of juvenile Micropterus salmoides. Based on the second-order polynomial regression analysis of WG or the FCR, the appropriate inclusion level of dietary cerium for juvenile largemouth bass was estimated to be 57.9 and 60.0 mg/kg, respectively. Full article

Dietary bioactive compounds are increasingly explored as complementary cardioprotective strategies, and the nitration of unsaturated fatty acids has emerged as a process capable of enhancing antiplatelet properties. This study investigated whether Phaseolus vulgaris L. extracts can generate nitrated fatty acids under gastric-like conditions and evaluated their effects on human platelet function. Bean extracts and major fatty acids were nitrated in vitro and tested using washed platelets to assess cytotoxicity, TRAP-6 and collagen-induced aggregation, activation markers (P-selectin, CD63), and mitochondrial responses including membrane potential, ROS production, and Ca²⁺ dynamics. Nitrated extracts markedly inhibited TRAP-6 induced aggregation (IC₅₀ ≈ 1.8 mg/mL), whereas non-nitrated extracts showed minimal activity; this effect was reversed by β-mercaptoethanol, indicating dependence on electrophilic nitroalkenes. Fractionation revealed that the lipidic fraction accounted for most of the antiplatelet effect, and isolated nitrated fatty acids (NO₂-LN, NO₂-LA, NO₂-OA) displayed stronger inhibition than their native counterparts without increasing cytotoxicity. Nitrated species additionally reduced mitochondrial membrane potential and granule secretion without elevating ROS. These findings identify Phaseolus vulgaris L. as a natural source of bioactive nitrated fatty acids and support their potential as nutraceutical agents capable of modulating platelet activation and contributing to cardiovascular risk reduction. Full article

Research has demonstrated that incorporating nitrate into animal feed can effectively decrease methane production in ruminants, though its impact on carcass characteristics and meat attributes in Hu sheep requires further investigation. This experiment examined how a dietary inclusion of 3% calcium nitrate (CN) influenced slaughter parameters, meat properties, gut microbial populations, and host gene regulation in Hu sheep. The study involved sixty healthy male Hu sheep aged 120 days with comparable body weights (31.11 ± 3.39 kg), randomly allocated into two groups: a control group receiving standard feed (CON) and a CN-supplemented group. The trial lasted 60 days, including a 15-day adaptation period and a 45-day formal trial period. They were housed individually and fed twice daily (at 8:00 and 18:00). The findings revealed that CN supplementation notably reduced the water loss rate in the longissimus dorsi muscle (LD), elevated meat color brightness, and enhanced the proportion of polyunsaturated fatty acids (PUFA), particularly n-6 PUFA, along with the n-3/n-6 PUFA ratio. Conversely, it reduced the levels of saturated fatty acids such as myristic acid (C14:0) and oleic acid (C18:1n9t). Additionally, the treatment boosted ruminal Ammoniacal nitrogen content and total short-chain fatty acid production, thereby contributing to energy metabolism in the animals. Microbiological examination demonstrated that CN supplementation led to a decrease in Fibrobacterota and Methanobrevibacter populations within the ruminal environment, while promoting the growth of Proteobacteria in the duodenal region. The gene expression profiling of digestive tract tissues showed an increased activity in nitrogen processing genes (including CA4) and oxidative phosphorylation pathways (such as ATP6), indicating an improved metabolic efficiency and acid–base homeostasis in the host animals. These findings demonstrate that CN-enriched diets enhance the carcass characteristics of Hu sheep by modifying intramuscular lipid profiles through gastrointestinal microbial community restructuring and metabolic pathway adjustments. Such modifications affect energy utilization and acid–base equilibrium, ultimately impacting muscle characteristics and adipose tissue distribution, presenting viable approaches for eco-friendly livestock farming practices. Full article