The present review focuses on electrochemical methods for ascorbic acid assessment. The occurence, role, biological importance of vitamin C, as well as the non-electrochemical methods for its ...assessment are firstly reviewed. The electrochemical behavior of ascorbic acid is then illustrated, followed by a description of the potentiometric, voltammetric and amperometric methods for vitamin C content estimation in various media. Different methods for the development of electrochemical sensors are reviewed, from unmodified electrodes to different composites incorporating carbon nanotubes, ionic liquids or various mediators. From this perspective, the interaction between the functional groups of the sensor's material and the analyte molecule is discussed, as it is essential for the analytical characteristics obtained. The analytical performances of the potentiometric, voltammetric or amperometric chemical and biochemical sensors (linear range of analytical response, sensitivity, precision, stability, response time etc) are highlightened. The numerous applications of ascorbic acid electrochemical sensors in fields like food, pharmaceutical or clinical analysis, where vitamin C represents a key analyte, are also presented.
•The intensity and duration of supplemental blue light co-regulate plant growth, anthocyanin and vitamin C production in red lettuce.•Given the same total amount of supplemental light, high-intensity ...blue light applied over a short duration was more effective at enhancing chlorophylls and carotenoids, while low-intensity blue light over a long duration resulted in the highest yield.•Adequate intensity and application duration of supplemental blue light are both required for anthocyanin production.•Vitamin C was enhanced under the lowest intensity blue light applied over long duration only.
Red leaf lettuce (Lactuca sativa) typically requires high light intensities for adequate production of anthocyanins, which are phytopigments with antioxidant properties and potential health-promoting benefits. Plants grown under relatively low light conditions, e.g., in an indoor farm, often have low anthocyanins accumulation and may be perceived as lower in quality. Blue light has been shown to promote anthocyanin production, however, high-intensity blue light often causes reductions in leaf expansion and biomass accumulation. We investigated whether the same daily cumulative amount of supplemental blue light applied at varying intensities and durations (i.e., lower intensity over a longer duration or higher intensity over a shorter duration) at the end of production (EOP) may differentially affect plant growth and the accumulation of beneficial phytochemicals. Two red lettuce cultivars, ‘Rouxai’ and ‘Red Salad Bowl’, were grown under six light treatments: 1). white light applied at 180 µmol m−2 s−1 for 16 h/day throughout production (W180; control), 2–5). EOP supplemental blue light applied during the last seven days of production at 45 µmol m−2 s−1 for 24 h/day (EOP B45), 67.5 µmol m−2 s−1 for 16 h/day (EOP B67.5), 135 µmol m−2 s−1 for 8-h/day (EOP B135), or 270 µmol m−2 s−1 for 4 h/day (EOP B270), and 6). higher-intensity white light applied at 247.5 µmol m−2 s−1 for 16-h/day throughout production (W247.5). The EOP supplemental blue light treatments significantly enhanced anthocyanins production in both lettuce cultivars compared to both the control and the W247.5 treatments, with the highest anthocyanins content under intermediate supplemental blue light intensities and application durations (i.e., EOP B67.5 and B135). The extraction-based anthocyanin index in the EOP B67.5 and B135 treatments increased by 161–168 % in ‘Rouxai’ and by 180–181 % in ‘Red Salad Bowl’, compared to the control. However, a significant increase in total vitamin C level (by 47.2 %) was only found in ‘Rouxai’ receiving the B45 treatment compared to the control. Plant yield also differed among the EOP blue light treatments, with B45 resulting in the highest leaf area and fresh/dry biomass in both lettuce cultivars, comparable to those in W247.5. Interestingly, EOP B67.5 and B135 treatments led to the lowest yield among the four blue light treatments in both cultivars, likely due to reduced leaf expansion and possibly lower photosynthetic light use efficiency because of high anthocyanins accumulation. Our results indicate that, given the same amount of EOP supplemental blue light, plant growth, and quality could be more effectively promoted by controlling the blue light intensity and application duration. Adequate intensity and application duration of supplemental blue light are both required for optimal anthocyanin production in plants.
•A signal-on platform for assay of caspase-3 activity and cell apoptosis was reported.•The generated peptide-Cu(II) complex is a water oxidation electrocatalyst.•Caspase-3 was detected in the ...concentration range of 0.5 pg/mL to 2 ng/mL.•The sensor electrode can be used to evaluate drugs-induced cell apoptosis.
Caspase-3 is believed to be important for diagnosis and prognosis of apoptosis-relative diseases, serving as a reliable molecular biomarker and therapeutic target. In this work, we reported a simple and sensitive electrochemical method for evaluation of cell apoptosis by determining the activity of caspase-3. Specifically, a peptide substrate specific to caspase-3 was attached on the graphene electrode surface through the hydrophobic and π-stacking interactions. Cleavage of the peptide substrate by caspase-3 resulted in the exposure of an amino terminal Cu(II) and Ni(II)-binding (ATCUN) motif on the electrode surface. The ATCUN peptide fragment can interact with Cu(II) to produce an ATCUN-Cu(II) complex which exhibits good electrocatalytic property toward water oxidation. The catalytic current increased linearly with caspase-3 concentration ranging from 0.5 pg/mL to 2 ng/mL. The method showed a detection limit of 0.2 pg/mL for caspase-3 detection. Finally, the sensor electrode was used to evaluate cell apoptosis induced by four drugs (staurosporine, vitamin C, doxorubicin and cisplatin). This work should be valuable for diagnosis and prognosis of apoptosis-relative diseases and designing of novel protease biosensors.
Acerola (Malpighia emarginata DC.) is a fruit containing abundant ascorbic acid (AsA) and numerous functional phytochemicals. We previously reported that the intake of acerola juice increased the ...absorption of AsA in plasma of healthy Japanese subjects. The functional phytochemicals in acerola may influence the intestinal epithelial cells to increase the cellular uptake of AsA. Therefore, in this study, we compared the AsA uptake into Caco-2 cells between AsA alone and that in acerola juice at the same concentration using a human intestinal model. Caco-2 cells were incubated with 3 mM AsA and 3 mM AsA in acerola juice. Intracellular AsA contents gradually increased until 24 h upon incubation with both AsA alone and AsA in acerola juice; however, these contents when incubated with AsA in acerola juice, were significantly higher than those incubated with AsA alone at 2, 3, 4, 8, and 24 h. Furthermore, the mRNA expression level of the sodium-dependent vitamin C transporter (SVCT) 1 was significantly higher in the cells incubated with AsA in acerola juice than those incubated with AsA alone. Moreover, polyphenols such as cyanidin-3-glucoside chloride and quercetin enhanced the SVCT1 gene expression in Caco-2 cells. Collectively, these results suggest that acerola polyphenols enhances the SVCT1 gene expression in Caco-2 cells and promotes AsA uptake.
This study aimed to determine the efficacy of seven predominant wine terpenoids (i.e. α-pinene, limonene, myrcene, geraniol, linalool, nerol, and terpineol) against foodborne pathogenic bacteria, as ...well as to observe their antioxidant activities. Antibacterial activities were observed against foodborne pathogenic bacteria. MIC
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and MBC values for Escherichia coli, Salmonella enterica, and Staphylococcus aureus were in the ranges of 0.420-1.598 mg/mL and 0.673-3.432 mg/mL, respectively. The terpenoid α-pinene showed the strongest DPPH free radical scavenging (IC
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value = 12.57 ± 0.18 mg/mL) and the highest reducing power (213.7 ± 5.27 μg/mL of L-ascorbic acid equivalents). However, the DPPH free radical scavenging of the terpenoids was found to be lower than that of butylated hydroxytoluene, which is known to be a strong reducing agent. The seven predominant terpenoids in wines that were identified in this study could be new potential sources of natural antibacterial and antioxidant agents for use in the food industry.
Ultrasound performance at low energy densities (9–86 J/mL) on the quality attributes of freshly squeezed orange juice was compared to heat treatment (90 °C/1 min). Mild sonoprocessing improved orange ...juice's kinetic stability preserving its ascorbic acid (vitamin C) content. The ultrasound energy densities could not promote the inactivation of pectin methylesterase (PME) in the orange juice samples. However, higher energy densities contributed to their cloud stability along cold storage. In contrast, the heat processing inactivated 96.3% of PME, but thermally treated samples lost their cloudiness and had their ascorbic acid content reduced by 7%. Cloud stabilization after sonoprocessing was mainly attributed to acoustic cavitation performance to modulate particle size distribution. Ultrasound processing is a promising technique to solve one of the main technological issues of the freshly squeezed orange juice. However, mild sonoprocessing must be combined with other innovative non-thermal technologies to provide a safe and high-quality orange juice.
•Mild ultrasound processing improved freshly squeezed orange juice's cloud stability.•Sonoprocessing at low energy densities (9–86 J/mL) preserved the vitamin C content.•Thermally treated samples (90 °C/1 min) lost their cloudiness over cold storage.•Heat treatment (90 °C/1 min) reduced vitamin C content by 7%.•Near-infrared backscattering technique proved ultrasound performance to cloud stabilization.
The focus of the next-generation healthcare system has moved forward from single disease detection to comprehensive health interpretation, namely, from disease diagnosis to prophylaxis via the early ...management of sub-health status. Among the technologies, microneedles have emerged as an efficient and powerful tool to realize painless and real-time sensing in the interstitial fluid (ISF), offering promising solutions for dynamic and direct reflection of nutritional profiles. Herein, we present a film-like, multifunctional microneedle patch, that is composed of three laser-induced graphene (LIG) based electrodes for minimally invasive and timely detection of glucose and vitamin C in the ISF. The microneedle patch is simply fabricated with a thickness of ∼0.25 mm polyimide (PI) film by a commercial laser platform, where laser-engraving is operated to form graphene electrodes, and laser-cutting accounts for the needle-tip shaping. Such fast, low-cost, and scalable manufactured microneedle patches showed excellent performance for electrochemical sensing and therefore allowed reliable on-the-tip monitoring of changes in glucose and vitamin C levels. Long-term studies in vivo and demonstrations in planta indicated the great promise of our microneedle patch to revolutionize dietary guidelines based on individualized status for effective nutrition management.
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•A strategy has been developed for manufacturing flexible and disposable microneedle patches.•Multifunctional microneedle patches have been proposed for minimally invasive detection of glucose and vitamin C in the interstitial fluid or food intake.•Versatile features enabled real-time monitoring and analysis of nutritional molecules in the rat models.
Objective: An imbalance has been reported in the oxidant-antioxidant system of infants with febrile convulsion. This study aimed to compare serum vitamin C levels between febrile children with or ...without seizures. Materials and Method: This multicenter case-control study was conducted on febrile infants and children who were referred to the pediatric emergency wards of Mashhad University of Medical Science. The subjects were equally divided into two febrile groups of case (with seizure) and control (without seizures). Visible Spectrophotometer was used to determine the total vitamin C level.Results: In total, 100 febrile children were included in this study. Based on the results, there was no statistically significant difference between the two groups in terms of age, gender, and family history of febrile convulsion (FC) (P>0.05). The mean vitamin C levels in the case and control groups were 42.73±7.2 and 78.59±11.1 µg/l, respectively. There was a significant difference between the groups regarding the vitamin C level (P<0.001). Regression analysis revealed that age (P=0.74), gender (P=0.66), and family history of febrile convulsion (P=0.52) had not any correlation with vitamin C levels. On the other hand, the vitamin C levels was associated with FC (P=0.001).Conclusion: The serum levels of vitamin C in the children with febrile seizure were lower than those in the control group. Thus, the reduced vitamin C levels can be considered as a predisposing factor for FC.
Nutrients are essential for the healthy development and proper maintenance of body functions in humans. For adequate nourishment, it is important to keep track of nutrients level in the body, apart ...from consuming sufficient nutrition that is in line with dietary guidelines. Sweat, which contains rich chemical information, is an attractive biofluid for routine non‐invasive assessment of nutrient levels. Herein, a wearable sensor that can selectively measure vitamin C concentration in biofluids, including sweat, urine, and blood is developed. Detection through an electrochemical sensor modified with Au nanostructures, LiClO4‐doped conductive polymer, and an enzymes‐immobilized membrane is utilized to achieve wide detection linearity, high selectivity, and long‐term stability. The sensor allows monitoring of temporal changes in vitamin C levels. The effect of vitamin C intake on the sweat and urine profile is explored by monitoring concentration changes upon consuming different amounts of vitamin C. A longitudinal study of sweat's and urine's vitamin C correlation with blood is performed on two individuals. The results suggest that sweat and urine analysis can be a promising method to routinely monitor nutrition through the sweat sensor and that this sensor can facilitate applications such as nutritional screening and dietary intervention.
A wearable nutrient tracker that allows monitoring of vitamin C in sweat, along with urine and blood, to assist tracking users’ nutritional status is demonstrated. A longitudinal study is performed on two individuals to explore correlations of vitamin C concentrations in sweat and urine with blood. It has promising potential applications in nutritional assessment and dietary intervention.
Inevitable prolonged fasting time before surgery leads to inflammatory reactions, surgery-related stress response, and consequently unfavorable outcomes; thus, developing strategies to mitigate these ...consequences is crucial.
In this study, we evaluated the effect of ascorbic acid on stress response reduction in abdominal hysterectomy following prolonged fasting time.
Eligible women candidates for abdominal hysterectomy following prolonged fasting time were enrolled in the study and divided into 2 groups of vitamin C group C; 1 g intravenously (IV) before surgery and placebo (group P). Before induction of anesthesia, C-reactive protein (CRP), mean arterial pressure (MAP), heart rate (HR), and blood sugar (BS) were measured and compared between the 2 groups at 4-point times, 24 and 48 hours immediately after extubation.
Finally, the data of 80 patients were included for the final analysis. A statistically significant difference was observed between the 2 groups in terms of CRP and BS values in T1 CRP serum levels; at the end of the study, CRP values were 0.5 ± 0.55 and 0.92 ± 0.69 in groups C and P, respectively (P = 0.012), and BS levels were 124.12 ± 18.11 and 152.0 ± 17.36 in groups C and P, respectively (P = 0.0001). However, this significant difference was not observed at T2 regarding CRP (P = 0.145) and BS (P = 0.135), as well as at T3 regarding CRP (P = 0.282) and BS (P = 0.213). However, according to both CRP and BS values, the trend of changes from T0 to T3 was significant in the 2 groups (P < 0.0001). Hemodynamic parameters were not significantly different between the 2 groups. No adverse event was reported in the 2 groups.
We found that ascorbic acid could induce short-term positive effects in abdominal hysterectomy following prolonged fasting time. Obviously, the optimal dosage, timing, and specific cases that benefit the most from this intervention should be investigated.
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