Antioxidant Capacity, Nitrite and Nitrate Content in Beetroot-Based Dietary Supplements

Quality decline of prepared dishes stored at 4 °C: Microbial regulation of nitrite and biogenic amine formation

Prepared dishes have high water content and complex nutritional composition, making them highly susceptible to microbial contamination and oxidative spoilage during storage. To elucidate the effects of microorganisms on the quality of prepared dishes and the formation of contaminants, the dishes "stewed pork with cabbage" were stored at 4 °C for 0, 1, 3, 5, and 7 days. Techniques such as high-performance liquid chromatography (HPLC), ion chromatography (IC), and 16S rRNA sequencing were used to explore changes in quality of the prepared dishes. The results showed that the total volatile basic nitrogen (TVB-N) and total viable count (TVC) consistently increased at similar rates during storage. The thiobarbituric acid reactive substances (TBARS) value reached 1 mg MDA/kg after 7 days of storage. Nitrite content and nitrate reductase activity rose as nitrate content decreased with longer storage. The contents of four free amino acids (FAAs) (Glu, His, Phe, Lys) and biogenic amines (BAs) (Putrescine, Histamine, Phenethylamine, Cadaverine) showed opposite trends. The abundance of the dominant genus, including Brochothrix, Acinetobacter and Weissella was significantly (P < 0.05) changed after the 3rd day of storage. Brochothrix, Acinetobacter, Pseudomonas, and Weissella promoted the decarboxylation of FAAs to form (BAs). Acinetobacter and Brochothrix accelerated the conversion of nitrate to nitrite. This study elucidates degradation of the quality of prepared dishes and the effect of five genera (Brochothrix, Acinetobacter, Pseudomonas, Weissella and Brochothrix) on the formation of nitrite and BAs, providing important theoretical support for enhancing nutritional quality and preserving the freshness during storage of prepared dishes.

Selective and simultaneous electrochemical detection of nitrite and nitrate ions using Ag-MOF: Food and water analyses

We report the synthesis of metal organic framework (MOF) based on Ag and phenylenediamine (C6H4(NH2)2) and its application for detection of both nitrites and nitrates. Ag-MOF modified glassy carbon electrode (GCE) revealed a significantly higher electrocatalytic activity towards selective oxidation of NO2- and reduction of NO3- over wider concentration ranges of 4-4040 μmol/L and 20-4750 μmol/L respectively and the corresponding lowest detection limits have been deduced as 0.045 μmol/L and 12 μmol/L. Interestingly, cyclic voltammetric measurements at Ag-MOF/GCE in phosphate buffer saline (pH 5.0) exhibited both anodic (NO2-) and cathodic (NO3-) peaks indicating the possibility for simultaneous detection of the two nitrogen compounds. Further, the fabricated electrode has been successfully used to determine NO2- and NO3- concentrations in beetroot, spinach, canned chicken and pond water with excellent relative standard deviation (RSD) values and recovery percentages. The results suggest the potential application of the fabricated sensor for food and environmental analyses.

Effects of Plant Substitutes for Nitrite on the Technological Characteristics of Fermented Sausages: A Comprehensive Review

Meat and its derivatives stand out as valuable sources of premium proteins, essential B-complex vitamins, and minerals. The processing of raw meat, a common practice for creating diverse products like sausages and hams, traditionally involves the use of curing salts, predominantly sodium nitrates and nitrites These salts confer several advantages, encompassing color stabilization, inhibition of spoilage-causing microorganisms such as Clostridium perfringens, Clostridium botulinum, and enhancement of the final product's flavor and aroma. Despite their benefits, the utilization of curing salts raises concerns about potential health risks, particularly the association with an increased risk of esophageal, stomach, and bladder cancers due to the formation of nitrosamine hormone-like chemicals. To mitigate the intake of nitrites and nitrates, various natural alternatives, including spinach, celery, radish, lettuce, carrots, and beets, have been proposed. This review critically evaluates plant-based substitutes for nitrates and nitrites, examining their influence on the quality, flavor, microbial communities, and physicochemical properties of fermented sausages. By delving into these alternatives, the review aims to contribute valuable insights into developing healthier and more sustainable approaches in the processing of fermented sausages.

The acute effects of dietary nitrate supplementation on postmenopausal endothelial resistance to ischemia reperfusion injury: a randomized, placebo-controlled, double blind, crossover clinical trial

Postmenopausal cardiovascular health is a critical determinant of longevity. Consumption of beetroot juice (BR) and other nitrate-rich foods is a safe, effective non-pharmaceutical intervention to increase systemic bioavailability of the vasoprotective molecule, nitric oxide, through the exogenous nitrate (NO3 -)-nitrite (NO2 -)-nitric oxide (NO) pathway. We hypothesized that a single dose of nitrate-rich beetroot juice (BRnitrate 600 mg NO3 -/140 mL, BRplacebo ∼ 0 mg/140 mL) would improve resting endothelial function and resistance to ischemia-reperfusion (IR) injury to a greater extent in early-postmenopausal (1-6 years following their final menstrual period (FMP), n = 12) compared to late-postmenopausal (6+ years after FMP, n = 12) women. Analyses with general linear models revealed a significant (p < 0.05) time*treatment interaction effect for brachial artery adjusted flow-mediated dilation (FMD). Pairwise comparisons revealed that adjusted FMD was significantly lower following IR-injury in comparison to all other time points with BRplacebo (early FMD 2.51 ± 1.18%, late FMD 1.30 ± 1.10, p < 0.001) and was lower than post-IR with BRnitrate (early FMD 3.84 ± 1.21%, late FMD 3.21 ± 1.13%, p = 0.014). A single dose of BRnitrate significantly increased resting macrovascular function in the late postmenopausal group only (p = 0.005). Considering the postmenopausal stage-dependent variations in endothelial responsiveness to dietary nitrate, we predict differing mechanisms underpin macrovascular protection against IR injury.

Beta vulgaris L. beetroot protects against iron-induced liver injury by restoring antioxidant pathways and regulating cellular functions

Beta vulgaris L. is a root vegetable that is consumed mainly as a food additive. This study aimed to describe the protective effect of B. vulgaris on Fe2+-mediated oxidative liver damage through in vitro, ex vivo, and in silico studies to establish a strong rationale for its protective effect. To induce oxidative damage, we incubated the livers of healthy male rats with 0.1 mM FeSO4 to induce oxidative injury and coincubated them with an aqueous extract of B. vulgaris root (BVFE) (15-240 µg/mL). Induction of liver damage significantly (p < .05) decreased the levels of GSH, SOD, CAT, and ENTPDase activities, with a corresponding increase in MDA and NO levels and Na+/K+ ATPase, G6 Pase, and F-1,6-BPase enzyme activities. BVFE treatment (p < .05) reduced these levels and activities to almost normal levels, with the most prominent effects observed at 240 µg/mL BVFE. An HPLC investigation revealed sixteen compounds in BVFE, with quercetin being the most abundant. Chlorogenic acid and iso-orientation showed the highest binding affinities for G6 Pase and Na+/K + ATPase, respectively. These findings suggest that B. vulgaris can protect against Fe2+-mediated liver damage by suppressing oxidative stress and cholinergic and purinergic activities while regulating gluconeogenesis. Overall, the hepatoprotective activity of this extract might be driven by the synergistic effect of the identified compounds and their probable interactions with target proteins.

Antioxidant Activity of Bougainvillea spectabilis Bracts as an Alternative to Nitrites in Cooked Pork Ham

In this study, the impact of incorporating Bougainvillea spectabilis powder into ham formulation as a potential color replacement for nitrites was evaluated. Three drying methods were proposed to preserve the antioxidant properties of bougainvillea: foam-mat drying, air drying, and oven drying. Antioxidant assays (DPPH, ABTS, and FRAP) assays revealed that the presence of bougainvillea powders enhanced the antioxidant properties and maintained the stability of the ham over 8 weeks of storage at 4 °C. In addition, total polyphenolic content and presence of thiobarbituric acid reactive substances (TBARS) were evaluated and showed higher and lower scores, respectively, in the samples with the incorporation of bougainvillea compared to the control samples, suggesting their potential to replace nitrite salts by providing natural antioxidant protection. Sensorial analysis also revealed no significant differences in sensory attributes in hams with 0.1% bougainvillea powder compared to nitrite samples. The incorporation of the bougainvillea powders in the ham formulation improved the sensorial attributes and consumer overall acceptance even after 8-week cold storage at 4 °C.

The Cardioprotective Role of Nitrate-Rich Vegetables

Nitric oxide (NO) is an inorganic radical produced by both the non-enzymatic nitrate (NO3-)-nitrite (NO2-)-NO pathway and enzymatic reactions catalyzed by nitric oxide synthase (NOS). Also, as nitrate and nitrite from dietary and other endogenous sources can be reduced back to nitric oxide in vivo, the endogenous NO level can be increased through the consumption of nitrate-rich vegetables. Ingestion of dietary NO3- has beneficial effects which have been attributed to a subsequent increase in NO: a signaling molecule that may regulate various systems, including the cardiovascular system. A diet rich in NO3- from green leafy and root vegetables has cardioprotective effects, with beetroot products being particularly good sources of NO3-. For example, various studies have demonstrated a significant increase in nitrite levels (regarded as markers of NO) in plasma after the intake of beetroot juice. The present review describes the current literature concerning the role of nitrate-rich vegetables (especially beetroot products) in the prophylaxis and treatment of cardiovascular diseases (CVDs). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, Web of Knowledge, Sci Finder, Web of Science, and SCOPUS.

A review on nitrates' health benefits and disease prevention

Dietary nitrates (NO3-) are naturally occurring compounds in various vegetables, especially beetroot, which is mainly supplemented in the form of BRJ. Dietary nitrates (NO3-) play a crucial function in human physiology. On consumption, nitrates (NO3-) undergo a conversion process, producing nitric oxide (NO) via a complex metabolic pathway. Nitric oxide (NO) is associated with many physiological processes, entailing immune modulation, neurotransmission, and vasodilation, enabling blood vessel dilation and relaxation, which boosts blood flow and oxygen delivery to tissues, positively influencing cardiovascular health, exercise performance, and cognitive function. There are various analytical processes to determine the level of nitrate (NO3-) present in dietary sources. The impact of dietary nitrates (NO3-) can differ among individuals. Thus, the review revisits the dietary source of nitrates (NO3-), its metabolism, absorption, excretion, analytical techniques to assess nitrates (NO3-) content in various dietary sources, and discusses health effects.