Intense Blue Color Research Articles

Insight into the chemistry of Folin’s test for uric acid

Folin developed an analytical technique for uric acid spectroscopic determination. It is based on the interaction of uric acid with sodium tungstate in phosphoric acid. This produces an intense blue colour after alkalinization, whose concentration is measured. However, the structure of the organic product obtained was not mentioned. The present communication gives the references related to each reaction step, as well as information about the reaction products obtained in uric acid oxidations carried-out in acidic or in alkaline mediums. The reaction route is as follows: addition of tungstic acid to the C-C double bond, acidolysis of the organo-metallic ester, producing tungstic subacid and an epoxide. Oxirane opening to vicinal diol after reaction with water. Two carbinolamines result, which are broken by protonation at the nitrogen; carbonyl groups are formed at C-4 and C-5 with concomitant elimination of a urea molecule. This way alloxan monohydrate is formed. The blue products obtained are described.

Carboxy-PEG-thiol functionalized gold nanoparticle conjugates for the detection of SARS-CoV-2: Detection tools and analytical method development

Addressing the need for accessible SARS-CoV-2 testing, carboxy-PEG 12-thiol functionalized gold nanoparticles conjugates were developed for rapid point-of-care (POC) detection against SARS-CoV-2 spike protein, pseudo-SARS-CoV-2, and authentic Beta SARS-CoV-2 virus particles. These conjugates leverage gold nanoparticles (AuNPs) as signal transducers, cross-linked to either angiotensin-converting enzyme 2 (ACE2) or SARS-CoV-2 spike protein receptor-binding domain (RBD) antibodies as bioreceptors and showed a distinct color shift from pink to blue. To assess their POC feasibility, the conjugates were integrated into facemasks and breathalyzers, wherein aerosolized SARS-CoV-2 antigens were successfully detected, producing a color change within 10 and 30 minutes for the breathalyzer and facemask prototypes, respectively. Furthermore, we explored quantitative analysis using varying concentrations of SARS-CoV-2 spike protein. Both conjugates demonstrated a linear relationship between blue color intensity and virus concentration, with linear ranges of 0.08–0.6 ng/mL and 0.04–0.5 ng/mL, respectively. Low limits of detection and quantification were also achieved. They exhibited specificity, responding solely to SARS-CoV-2 even in complex matrices containing diverse proteins, including the SARS-CoV-1 spike protein. Precision tests yielded coefficient of variations below 2 %, showcasing their remarkable reproducibility. This work presents a promising approach for rapid, sensitive, and specific POC detection of SARS-CoV-2 paving the way for improved pandemic response and management.

Bimetallic metal-organic framework-based molecularly imprinted sensors for selective on-site detection of 2,4-dichlorophenoxyacetic acid

Designing and constructing simple and selective sensors for the on-site recognition of 2,4-dichlorophenoxyacetic acid (2,4-D) is both significant and challenging. Here, we report the development of molecularly imprinted sensors (Zn/Co-MOF@MIPs) utilizing bimetallic metal-organic frameworks as supporting carriers and catalysts, constructed via surface imprinting for the rapid detection and determination of 2,4-D. Zn/Co-MOF@MIPs exhibited oxidase-like activity, catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to yield a blue-colored oxidized TMB in the absence of H2O2. The high affinity of the imprinted layer for 2,4-D selectively reduced the oxidase-like activity of Zn/Co-MOF@MIPs in the presence of 2,4-D, resulting in a significant decrease in blue color intensity. The absorbance at 650 nm gradually decreased with increasing 2,4-D concentration. Furthermore, we established a colorimetric method based on Zn/Co-MOF@MIPs for the rapid detection of 2,4-D in environmental water. This sensing platform exhibited sensitivity and selectivity for detecting 2,4-D, with a low detection limit of 2.26 μM. These findings underscore the outstanding potential of Zn/Co-MOF@MIPs for environmental chemistry sensing applications.

Structural characterization and luminescence characteristics of Dy3+ doped Sr9Y2W4O24 phosphor for application in white-LEDs

In this research, a series of Dy3+ ions doped Sr9Y2W4O24 (SYWO) phosphors was prepared for the application in white-LEDs and display devices. The structure, surface, and photo-luminescent (PL) behaviour of the samples were studied. X-ray diffraction (XRD) and Fourier Transform Infra-Red (FT-IR) spectroscopy indicated the formation of single phase particles with no contaminants with various vibrational bands present in the host lattice. The synthesised powders showed agglomeration with the average crystallite size to be in the range of 22–27 nm. The optical band gaps were estimated using diffuse reflectance spectral (DRS) data. The emission spectra of SYWO: xDy3+ (1.0, 2.0, 3.0, 4.0, & 5.0 mol%) have been obtained at different excitation wavelengths of 354, 367, and 391 nm. The SYWO phosphors emit intense blue and yellow colors at 491 nm (4F9/2 → 6H15/2), 576 nm (4F9/2 → 6H13/2) & 679 nm (4F9/2 → 6H11/2), respectively. Furthermore, from the CIE 1931 diagram, it is evident that the emission from these Dy3+ doped phosphors lies in the white region. The lifetime of excited Dy3+ ions decreased with increasing Dy3+ concentration as seen in the luminescence decay graphs. Finally, to determine the phosphor's luminescence thermal stability, temperature dependent photoluminescence (TD-PL) was recorded and the activation energy calculated from this study was found to be 0.231 eV. In the light of aforementioned results, we can conclude that Dy3+ doped Sr9Y2W4O24 phosphors could be used in construction of w-LEDs or as white-emitting luminescent materials in various photonic devices and other photonic applications.

Description of a Non-Canonical AsPt Blue Species Originating from the Aerobic Oxidation of AP-1 in Aqueous Solution.

The peculiar behavior of arsenoplatin-1, ([Pt(µ-NHC(CH3)O)2ClAs(OH)2], AP-1), in aqueous solution and the progressive appearance of a characteristic and intense blue color led us to carry out a more extensive investigation to determine the nature of this elusive chemical species, which we named "AsPt blue". A multi-technique approach was therefore implemented to describe the processes involved in the formation of AsPt blue, and some characteristic features of this intriguing species were revealed.

Therapeutic potential of Phycocyanin in gastrointestinal cancers and related disorders.

Gastrointestinal cancer is the most fatal cancer worldwide. The etiology of gastrointestinal cancer has yet to be fully characterized. Alcohol consumption, obesity, tobacco, Helicobacter pylori and gastrointestinal disorders, including gastroesophageal reflux disease, gastric ulcer, colon polyps and non-alcoholic fatty liver disease are among the several risks factors for gastrointestinal cancers. Phycocyanin which is abundant in Spirulina. Phycocyanin, a member of phycobiliprotein family with intense blue color, is an anti-diabetic, neuroprotective, anti-oxidative, anti-inflammatory, and anticancer compound. Evidence exists supporting that phycocyanin has antitumor effects, exerting its pharmacological effects by targeting a variety of cellular and molecular processes, i.e., apoptosis, cell-cycle arrest, migration and Wnt/β-catenin signaling. Phycocyanin has also been applied in treatment of several gastrointestinal disorders such as, gastric ulcer, ulcerative colitis and fatty liver that is known as a risk factor for progression to cancer. Herein, we summarize various cellular and molecular pathways that are affected by phycocyanin, its efficacy upon combined drug treatment, and the potential for nanotechnology in its gastrointestinal cancer therapy.

The Role of WO3 Nanoparticles on the Properties of Gelatin Films.

Gelatin films are very versatile materials whose properties can be tuned through functionalization with different systems. This work investigates the influence of WO3 nanoparticles on the swelling, barrier, mechanical, and photochromic properties of gelatin films. To this purpose, polyvinylpirrolidone (PVP)-stabilized WO3 nanoparticles were loaded on gelatin films at two different pH values, namely, 4 and 7. The values of swelling and solubility of functionalized films displayed a reduction of around 50% in comparison to those of pristine, unloaded films. In agreement, WO3 nanoparticles provoked a significant decrease in water vapor permeability, whereas the decrease in the values of elastic modulus (from about 2.0 to 0.7 MPa) and stress at break (from about 2.5 to 1.4 MPa) can be ascribed to the discontinuity created by the nanoparticles inside the films. The results of differential scanning calorimetry and X-ray diffraction analysis suggest that interaction of PVP with gelatin reduce gelatin renaturation. No significant differences were found between the samples prepared at pH 4 and 7, whereas crosslinking with glutaraldehyde greatly influenced the properties of gelatin films. Moreover, the incorporation of WO3 nanoparticles in gelatin films, especially in the absence of glutaraldehyde, conferred excellent photochromic properties, inducing the appearance of an intense blue color after a few seconds of light irradiation and providing good resistance to several irradiation cycles.

Assessing Aluminum Stress Resilience in Common Bean Roots: Phenotypic, Histochemical, and PvGST/PvPOD Gene Expression Analysis

Common bean (Phaseolus vulgaris L.) is grown in various parts of the world. Aluminum (Al) toxicity poses a significant and widespread challenge in marginal areas with unfavorable soil qualities where common bean is grown. In acidic soils, stable forms of Al dissolve into the soil solution and inhibit root growth and function by injuring the root apex with phytotoxic ions. This leads to the development of a smaller root system, adversely affecting crop yield. In this study, the phenotypic evaluation for relative root elongation of 10 common bean genotypes/cultivars under Al stress (50 µM), the impact of Al toxicity using different histochemical dyes (Evan’s blue and Schiff’s reagent) and the expression levels of PvGST (Glutathione S-transferases) and PvPOD (peroxidase) genes in the root tissues of the most resistant/sensitive common beans under Al stress (50 µM) and control conditions (0 µM) were investigated. The maximum relative root elongation value (71.9%) was found in Önceler-98 cultivar, while the lowest value (14.1%) was obtained from Blksr-19 genotype. Histochemical applications used in the study supported phenotypic results. The cracks at the root tip and high blue color intensity were detected in Schiff’s reagent and Evan’s blue dyes in the Blksr-19, respectively. The expression levels of PvGST and PvPOD genes in the root tissue of the Blksr-19 (Al-sensitive) were highly upregulated at 24 h of Al stress treatment. The results revealed that these genes might be involved in the common bean root tissue's defense mechanism against Al stress for the first time. The findings herein will help plant breeders develop common bean cultivars tolerant to Al toxicity.

The Effect of Nitrogen Reduction and Applying Bio-Organic Fertilisers on Soil Nutrients and Apple Fruit Quality and Yield

In this study, we investigated the effect of partially substituting inorganic nitrogen with bio-organic fertiliser on the ‘Tianhong2’ Fuji apple planting in Xinjiang. Bio-organic fertiliser was applied, and nitrogen was reduced by 20% (T2), 40% (T3), and 60% (T4) during the blooming and fruit expansion periods with conventionally fertilised fields used as control (T1); soil nutrient, soil enzyme activity, leaf nutrients, fruit quality, and yield were measured. The total nitrogen (TN), total phosphorus (TP), total potassium (TK), total calcium (TCa), available phosphorus (AP), available potassium (AK), and soil organic matter (SOM) contents, as well as the soil catalase (S-CAT), soil uretrase (S-UE), soil saccharase (S-SC), and soil nitrate reductase (S-NR) activities, significantly increased in the experimental soils compared with those in T1. In addition, TP, TCa, and total magnesium (TMg) content in apples significantly increased. Compared to T1, the T2 and T3 treatments significantly improved the fruit yield and quality, increasing the sugar–acid ratio, soluble protein, soluble sugar, peel carotenoid, and anthocyanin content and reducing peel chlorophyll content. The brightness (L*), red–green axis (a*), yellow–blue axis (b*), colour intensity (C), and tone (h°) values changed. The yield per hectare and nitrogen fertiliser partial productivity values were significantly increased. Overall, the T2 treatment resulted in the best outcome for the Yili area. In conclusion, partially substituting inorganic nitrogen with bio-organic fertiliser can effectively increase soil and leaf nutrient content and improve fruit yield and quality.

One-Pot Hydrothermal Synthesis of mSiO2-N-CDs with High Solid-State Photoluminescence as a Fluorescent Probe for Detecting Dopamine

An effective fluorescent probe (mSiO2-N-CDs) was prepared by embedding N-CDs into mesoporous silica via a simple one-pot hydrothermal reaction and applied to the detection of dopamine (DA). Mesoporous silica not only provided a skeleton to prevent the aggregation of N-CDs but also a medium for the centrifugal collection of N-CDs, avoiding the need for dialysis and freeze-drying. The formation process, phase composition, morphology, and luminescence properties of the composite were studied in detail. The synthesized mSiO2-N-CDs possessed spherical morphology, a smooth surface, and a diameter of approximately 150 nm. The fluorescence results indicated that mSiO2-N-CDs emitted intense blue color fluorescence at 465 nm under the optimal excitation of 370 nm. Because the mesoporous silica effectively inhibited the self-quenching caused by the aggregation of N-CDs, the quantum yield of solid mSiO2-N-CDs powder reached 32.5%. Furthermore, the emission intensity of the solid mSiO2-N-CDs remained constant for 28 days. The good sensitivity and selectivity of mSiO2-N-CDs for DA enabled the establishment of a rapid, simple, and sensitive DA detection method. The linear range was 0–50 µM and the limit of detection was calculated to be 107 nM. This method was used for the determination of DA in urine, with recovery rates ranging between 98% and 100.8%. In addition, the sensing mechanism was characterized by fluorescence lifetime decay and UV–VIS spectral analysis.

Lanthanum nitrogen Co-doped carbon quantum dots as optical and smartphone sensors for serotonin detection

A simple bottom up approach using hydrothermal technique was applied to prepare lanthanum and nitrogen Co-doped carbon quantum dots and were characterized by XRD, EDS, TEM, SEM FT-IR, XPS, fluorescence and UV-VIS spectroscopy to study their crystal structure, elemental and chemical composition, particle size, morphology and optical properties. It was found that morphology was spherical and particle size was 3–4 nm. EDS and XPS helps to prove the successful doping of lanthanum and nitrogen to carbon quantum dots with excitation and emission wavelengths 340 and 445 nm respectively. The intense blue color of fluorescent QDs were quenched with addition of serotonin due to the electrostatic interactions, π-π stacking interaction and may be due to complex formation between La,N-CQDs/Ser and the static quenching mechanism with inner filter effect has been observed. These La,N-CQDs were used as fluorescent probes for sensitive and selective detection of serotonin in a good linear range of 0–38 nM with low limit of detection 7.4 nM.The smartphone based portable detection was also developed for detection of serotonin providing the reliable information for analysis of color change and real sample analysis studies were also carried out. The uniqueness, high sensitivity and accuracy of the optical probe that was constructed are confirmed and this method's LOD is also highly competitive.

Colorimetric Sensing of Ascorbic Acid Using Cu-Phen MOFs and Subsequent Digital Image Analysis with Smartphone

Vitamin C, also known as ascorbic acid, is a crucial nutrient involved in a number of enzymatic processes for tissue healing. Additionally serving as an antioxidant, ascorbic acid is crucial for keeping the immune system strong. It is essential to create a quantitative analytical approach to ascertain ascorbic acid concentration in many samples since its consumption from the daily food should be in the proper quantity. Here, we present a colorimetric probe made of synthetic metal-organic frameworks (MOFs) that changes its color only when samples containing ascorbic acid are present. In this study, phenanthroline served as an organic ligand or linker while copper served as the core metal that formed bonds with it. Cu-Phen MOF color fluctuations at 410 nm (from 408 nm to 412 nm) are linearly related to variations in light absorption. Moreover, as a substitute for spectrophotometry UV-visible, we have created a digital image-based colorimetry. The Cu-Phen MOFs’ color change has the maximum slope and linearity when the blue color intensity is used. The detection limit with high precision of 4.2% under ideal circumstances was 0.1 ppm. The established approach allowed for the exact and accurate assessment of ascorbic acid in genuine samples of star fruit (Averrhoa carambola L.).

Uncovering the synergistic interplay of melatonin and spermidine in the alleviation of nematode stress in Solanum lycopersicum

Worldwide, biotic stress severely degrades agricultural output and increases the risk of starvation. Root-knot nematodes (Meloidogyne incognita) are one of the important endoparasites that adversely affect the growth and development in plants, thus affecting their productivity. Contrarily, humans employ a number of unfriendly techniques, such as chemical applications, to manage biotic stressors. Use of Plant Growth Regulators is an environmentally safe alternative method against chemical pesticides that can be used to defend plants from biotic stressors. Melatonin and polyamines have been broadly found in multiple physiological processes and in diverse biotic and abiotic stresses faced by plants. In the contemporaneous study, we conducted an in vitro experiment which disclosed that pretreated seeds with melatonin and spermidine (a polyamine), decreased root galls in afflicted plants and uplifted the growth of Solanum lycopersicum seedlings. According to our findings, tomato plants' photosynthetic efficiency dropped and reactive oxygen species levels dramatically rose after nematode inoculation. On the other hand, melatonin and spermidine decreased oxidative stress by scavenging hydrogen peroxide and decreased malonaldehyde. The present work investigated improvement in growth characteristics, photosynthetic pigments, antioxidative enzymes and non-antioxidative enzymes in PGR treated tomato seedlings even during the nematode stress. Confocal studies evaluated nuclear damage within root apices and intensity of blue colour was directly proportional to nuclear damage. The findings of the present investigation support the use of plant growth regulators, melatonin and spermidine as seed priming agent to manage nematode stress in plants.

Physical characterization of genipin complexes coupled with multivariate data analysis to assess formed pigments

The potential of electrophoretic mobility and dynamic light scattering (DLS) was investigated to assess pigment formation in aqueous solution after the genipin reaction with different amino acids by separate. Absorbance, mobility, hydrodynamic size, polydispersity index, and conductivity of the aqueous solutions were measured after the reaction. Only complexes derived from genipin and leucine, tyrosine, arginine, lysine, and glycine developed dark blue colors. From all measured variables, complex size was correlated with their blue color intensity, and darkest blue complexes showed the highest hydrodynamic size (1073–4179 nm). Moreover, size pigments below 1 µm were obtained for all amino acids at different concentrations of genipin and amino acid, except for arginine. A partial least squares (PLS) model for size was built and exhibited a good ability to describe the distribution in blue complexes formed after the reaction of genipin and excess of amino acid (mM): (R2adj = 0.88; RMSE = 0.94). Electrophoretic mobility and DLS coupled with multivariate analysis is a useful tool as it can give reliable assessment of the physical properties of aqueous solutions of genipin pigments.

The Mechanism of Frabot Test for Uric Acid

Uric acid is an Analyte. Excess uric acid ─ hyperuricemia ─ leads to gout and renal stones. Frabot noted that uric acid added to an alkaline tungstate solution developed an intense blue colour. A colorimetric method widely utilized to quantify uric acid depends on the reduction of the chromogen sodium tungstate by uric acid to produce a measurable colour change. The reaction route from the initial products to the coloured compounds and the oxido-degradation of the organic substance has not been advanced. In this communication the electron flow is given in each step of the series of reactions that take place. These are isomerization to imidol, Michael addition to enone, oxirane formation in a redox step, hydrolysis of imido group, oxirane ring opening, ring contraction to five- member ring, ring opening via alkoxide, and finally assisted decarboxylation to the end product, 5-ureido hydantoin (allantoin).

Colorimetric and fluorimetric pH sensing using polydiacetylene embedded within PVC‐PCL nanofibers

AbstractThe applicability of model polydiacetylenes (PDAs) in hydrogen ions sensitive optodes was tested. Nanofibers mats were electrospun using a mixture of polyvinyl chloride (PVC) and polycaprolactone (PCL) together with 10, 12‐tricosadiynoic acid (TCDA) or 10,12‐pentacosadiynoic acid (PCDA). After the polymerization the mats were applied in colorimetric and fluorimetric pH sensors. The PDAs were formed by photopolymerization with a UV lamp (254 nm), resulting in a change of mats color from white to dark blue. The morphology of both fiber mats is similar (SEM images), and the average diameters of fibers were estimated as equal to 228±73 and 248±61 nm for TCDA and PCDA, respectively. As the pH increases, the color of the fiber mat changes from blue to red and the process can be followed visually. The result obtained by computer image analysis showed a sigmoidal increase in the intensity of red and a decrease in the intensity of blue color with increasing pH. A similar sigmoidal response is observed for the dependence of the emission intensity on the pH. Changes in the recorded signal occur in the pH range from 7 to 8.5 or from 8 to 9.5 for mats with TCDA and PCDA, respectively. Both readout modes can be successfully used for pH sensing with proposed nanofibrous mats in the range of pH close to the physiological pH range.

Copper Sulfate-Induced Diphenylamine for Rapid Colorimetric Point-of-Care Detection of Contagious Pathogens Combined with Loop-Mediated Isothermal Amplification

Here, we developed a copper sulfate (CuSO4)-initiated diphenylamine (DPA)-based colorimetric strategy coupled with loop-mediated isothermal amplification (LAMP) for rapid detection of two critical contagious pathogens, SARS-CoV-2 and Enterococcus faecium. To detect the DNA, acid hydrolysis of LAMP amplicons was executed, enabling the development of a blue color. In the LAMP amplicons, the bond between the purines and deoxyribose is extremely labile. It can be broken using 70% sulfuric acid followed by phosphate group elimination, which generates a highly active keto aldehyde group. CuSO4 plays an imperative role inducing DPA to rapidly react with the keto aldehyde group, producing an intense blue color within 5 min. Moreover, low quantities such as 103 copies μL–1 of SARS-CoV-2 RNA and 102 CFU mL–1 of E. faecium were successfully detected, revealing the advantages of the introduced method. To confirm practical applicability, multiplex detection of pathogens was performed using a foldable microdevice comprising reaction and detection zones. Various reactions such as DNA extraction, LAMP, and acid hydrolysis occurred in the reaction zone. Then, colorimetric reagents (DPA, CuSO4, and ethylene glycol) contained in the detection zone were mixed with the keto aldehyde group by simply folding the microdevice, which was heated at 65 °C for 5 min for colorimetric detection. An intense blue color was developed where the target DNA was present. These results indicate that the method proposed in this study is highly suitable for point-of-care applications, especially in resource-limited settings for the rapid detection of harmful pathogens.

A cost-effective intense blue colour cobalt doped gahnite pigment for latent finger print, cheiloscopy and anti-counterfeiting applications

Alanine is used as a novel fuel in the solution combustion method (SCS) to produce nanocrystalline Co2+ (0.25–5 mol%) doped gahnite (ZnAl2O4: ZAO) nano pigments (NPs). A thorough investigation was conducted to comprehend the interaction of dopant (Co2+) and ZAO host matrix, as well as the influence of doping on their structural, optical, and luminescence properties. The powder samples were thoroughly characterized using XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Photoluminescence (PL) spectroscopic techniques. SEM micrographs of clearly exhibit the formation of dense particles, voids, and pores in the sample. In addition, tiny aggregates were detected on the surface of more prominent clusters. The nominal composition of Zn, Al, Co and O was assessed using Energy Dispersive X-Ray Analysis (EDS). The optimized ZAO:5Co2+ phosphor powder demonstrated levels 1–3 fingerprint (FP) features and groove patterns (types 1–5) of lip print that can be clearly recognised, with excellent resolution and contrast, under 320 nm UV light. The appropriate thickening agent and defoamer were added to blue pigment during fabrication to generate anti-counterfeiting (AC) inks that mark on multiple surfaces with high resolution without spreading or tracing. The preceding results suggest that the ZAO:Co2+ NPs can serve as a significant candidate for the detection and individualization of latent fingerprints (LFP), lip prints (LP) and anti-counterfeiting applications.

Comparative Study of Total Antioxidant Capacity (TAC) Levels of Pregnant Women on Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine and their Controls in Malaria Endeminicity

Background: The issue of malaria prevention in endemic areas during antenatal periods needs continuous emphasis so as to achieve its desired goals. Its roles in reducing the problems of malaria in pregnancy has been proven. The problems of anaemia in pregnancy, preterm labours, small for gestational age babies have been greatly reduced by adequate practice of Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine (IPT-SP). It is also advocated that optimal levels of antioxidants like Total Antioxidant status (TAC/TAS) is necessary to assist pregnant women enjoy uneventful pregnancies as well as avert other problems associated with pregnancy. Such problems may include preterm births, neonatal anaemias, intrauterine growth retardations (IUGR), increased admissions into special care baby units and even neonatal deaths. Objectives: We have comparatively studied the plasma Total Antioxidant Capacity / Status levels in parturients who received intermittent preventive treatment with sulphadoxine pyrimethamine (IPT-SP), and their controls during current confinements. Method: This study was carried out at the Federal Medical Centre (FMC), Owerri Nigeria. Owerri, the capital of Imo state Nigeria and has a typical malaria endemic setting as seen in most parts of Sub-Saharan Africa. Ethical clearance and subsequent certification were obtained from the ethics committee of FMC Owerri enabling the commencement of the longitudinal recruitment of participants. This was after an adequate counseling and informed consent involving both groups. As a laboratory based, cross-sectional descriptive study, it involved 296 participants who clearly satisfied the inclusion criteria for either the study or control groups as allotted longitudinal. Participants were followed up after recruitment through their entire antenatal course till delivery to enable collection of blood samples for the estimation of Total Antioxidant Status/Capacity which was done using the Ferric Reducing Ability of Plasma, FRAP; by (Benzie and Strain, 1996). The methodology principle is based on the fact that at low pH, antioxidant power causes the reduction of ferric tripyridyl triazine (Fe III TPTZ) complex to ferrous form (which has an intense blue colour) that can be monitored by measuring the change in absorption at 593nm. FRAP values are obtained by comparing the absorbance change at 593 nm in mixture (test), with those containing ferrous ion in known concentration (Standard). Data analysis: The data obtained was analysis using the computer Software Package for Social Science (SPSS) version 20.0 (SPSS, Inc, 2007, Chicago) while the descriptive statistics (mean, standard deviation, range, percentages etc) were determined for continuous variables. P-value less than (<0.05) at 95% confidence interval was considered statistically significant. Result: The mean serum level of total antioxidant status (TAS) in the study group was 846.55 umol/l while the minimum and maximum serum Total antioxidant status were 706 and 991 umol/l respectively. For their controls, the mean serum level of Total antioxidant status was 833.70 umol/l. However, the minimum and maximum serum Total antioxidant statuses were 291 and 1065 umol/l respectively. The difference was not statistically significant (p= 0.167) with odds ratio 1.00 (CI of 95% 0.997-1.006).

SPIRULINA (ARTHROSPIRA PLATENSIS) AS A COMPONENT OF FUNCTIONAL DRINKS

Background. Spirulina is categorized as so-called super foods, the properties of which are supposed to have a beneficial effect on the human body, and is used as a natural food coloring additive. The aim of the study was to evaluate the antioxidant and osmotic properties of beverages prepared using various forms of commercially available spirulina and coconut water as a natural isotonic solvent. Based on the determined absorption spectra and antioxidant properties of spirulina extracts (three batches of green and two batches of blue spirulina), samples with the highest activity were selected for the next stage of the study. Beverages were made using coconut water (control sample) and green or blue spirulina with increasing additions of 0.1, 0.25 and 0.5 % w/v (seven beverages in total). The polyphenol content, antioxidant (DPPH•) and osmotic properties of the produced beverages were compared. Results and conclusion. It was shown that drinks based on blue spirulina had higher protein, polyphenol content as well as antioxidant activity, proportional to the share of additive used, than drinks with green spirulina. The osmolality of all drinks ranged from 315 to 336 mOsm/kg H2O, which meets the requirements for isotonic drinks. Drinks based on blue spirulina were characterized by an intense blue color and better organoleptic characteristics compared to green spirulina and coconut water, however, the addition of 0.5% adversely affected the organoleptic qualities of the drink. The beverages produced can be categorized as functional beverages, well hydrating the body and additionally enriched with valuable nutrients.