Simultaneous Determination of Thiamine and Riboflavin in Edible Marine Seaweeds by High-Performance Liquid Chromatography

Nutritional and Health Benefits of the Brown Seaweed Himanthalia elongata

Himanthalia elongata is a brown seaweed containing several nutritional compounds and bioactive substances including antioxidants, dietary fibre, vitamins, fatty acids, amino acids, and macro- and trace- elements. A variety of bioactive compounds including phlorotannins, flavonoids, dietary fucoxanthin, hydroxybenzoic acid, hydroxycinnamic acid, polyphenols and carotenoids are also present in this seaweed. Multiple comparative studies were carried out between different seaweed species, wherein H. elongata was determined to exhibit high antioxidant capacity, total phenolic content, fucose content and potassium concentrations compared to other species. H. elongata extracts have also shown promising anti-hyperglycaemic and neuroprotective activities. H. elongata is being studied for its potential industrial food applications. In new meat product formulations, it lowered sodium content, improved phytochemical and fiber content in beef patties, improved properties of meat gel/emulsion systems, firmer and tougher with improved water and fat binding properties. This narrative review provides a comprehensive overview of the nutritional composition, bioactive properties, and food applications of H. elongata.

Optimization of nucleic acid extraction and amplification of a thiamine biosynthesis gene fragment from selected Malaysian seaweeds

Obtaining high-quality nucleic acid extracted from seaweeds is notoriously difficult due to contamination with polysaccharides and polyphenolic compounds after cell disruption. Specific methods need to be employed for RNA isolation in different seaweed species, and therefore studies of the thiamine biosynthesis pathway have been limited. Two selected Malaysian species which are highly abundant and underutilized, namely Gracilaria sp. and Padina sp., representing the red and brown seaweeds, respectively, were collected to develop optimized total RNA extraction methods. Prior to that, DNA was extracted, and amplification of the 18S rRNA gene and the THIC gene (encoding the first enzyme in the pyrimidine branch of the thiamine biosynthesis pathway) from the DNA template was successful in Gracilaria sp. only. RNA was then extracted from both seaweeds using three different existing methods, with some modifications, using cetyltrimethylammonium bromide, guanidine thiocyanate and sodium dodecyl sulphate. Methods I and III proved to be efficient for Padina sp. and Gracilaria sp., respectively, for the extraction of highly purified RNA, with A₂₆₀/A₂₈₀ values of 2.0 and 1.8. However, amplification of the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase and the THIC gene was successful in only Gracilaria sp. cDNA derived from extracted RNA. Further modifications are required to improve the exploitation of nucleic acids from brown seaweeds, which has been proven to be difficult. This work should pave the way for molecular studies of seaweeds generally and for the elucidation, specifically, of the thiamine biosynthesis pathway.

L-cysteine modified silver nanoparticles for selective and sensitive colorimetric detection of vitamin B1 in food and water samples

The use of L-cysteine modified silver nanoparticles (Cys-capped AgNPs) as a colorimetric probe for determination of vitamin B1 (thiamine) is described in the present work. This method is based on the measurement of red shift of localized surface plasmon resonance (LSPR) band of Cys-capped AgNPs in the region of 200–800 nm. The color of Cys-capped AgNPs was changed from yellow to colorless by the addition of vitamin B1. The mechanism for detection of vitamin B1 is based on the electrostatic interaction between positively charged vitamin B1, which causes the red shift of LSPR band from 390 nm to 580 nm. The interaction between Cys-capped AgNPs and vitamin B1 was theoretically explored by density function theory (DFT) using LANL2DZ basis sets with help of Gaussian 09 (C.01) program. The morphology, size distribution and optical properties of Cys-capped AgNPs were characterized by transmission electron microscope (TEM), UV-Visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) techniques. The method is linear in the range of 25–500 μg mL⁻¹ with correlation coefficient (R²) 0.992 and limit of detection of 7.0 μg mL⁻¹. The advantages of using Cys-capped AgNPs as a chemical sensor in colorimetry assay are being simple, low cost and selective for detection of vitamin B1 from food (peas, grapes and tomato) and environmental (river, sewage and pond) water samples.

Fatty acid and lipophilic vitamin composition of seaweeds from Antalya and Çanakkale (Turkey)

The lipophilic vitamin and fatty acid profiles were determined in five edible seaweeds: Corallina elongata J. Ellis & Solander, 1786; Cystoseira barbata (Stackhouse) C. Agardh, 1820; Jania rubens (Linnaeus) J.V. Lamouroux, 1816; Laurencia obtusa (Hudson) J.V. Lamouroux, 1813 and Sargassum vulgare C. Agardh, 1820. Saturated fatty acids (SFAs) were the major fatty acid group, and16:0 formed the highest SFA content (34–40%). 16:0 was higher in the brown seaweeds (C. barbata, 40.55%; S. vulgare, 37.11%) than in the red seaweeds (C. elongata, 36.5%; L. obtusa, 34.57%; J. rubens, 34.22%). The other major fatty acids in the seaweeds were 18:1n-9 and 16:1n-7 from MUFA in the analyzed species. In addition, EPA was found in significant levels in the red seaweeds, whereas DHA was not detected in the analyzed species. The findings showed that difference among species were not statistically significant (p = 0.09–0.11), yet differences between two families (Sargassaceae and Corallinaceae) were significant (p = 0.006) in the fatty acid profile (p < 0.01). Also, differences between the Corallinaceae and Rhomomelaceae families were partially significant (p = 0.011–0.013) (p < 0.01). K1 and K2 vitamins as well as δ-tocopherol, α-tocopherol and retinol acetate were determined to be present in the seaweed extracts. Finally, ergosterol, stigmasterol and ß-sitosterol were found in all samples in differing ratios per species.

Biomedical Properties of Edible Seaweed in Cancer Therapy and Chemoprevention Trials: A Review

This review article summarizes in vitro and in vivo experiments on seaweed anticancer activity and seaweed chemical components. Seaweed use in cancer therapy, chemopreventive randomized control trials (RCTs) and quasi-experiments are discussed. The literature reviewed in this article was obtained from various scientific sources and encompasses publications from 2000–2012. Seaweed therapeutic effects were deemed scientifically plausible and may be partially explained by the in vivo and in vitro pharmacological studies described. Although the mechanisms of action remain unclear, seaweed's anticancer properties may be attributable to its major biologically active metabolites. Much of the seaweed research outlined in this paper can serve as a foundation for explaining seaweed anticancer bioactivity. This review will open doors for developing strategies to treat malignancies using seaweed natural products.

Dispersive liquid-liquid microextraction coupled to liquid chromatography for thiamine determination in foods

A miniaturized dispersive liquid-liquid microextraction (DLLME) procedure coupled to liquid chromatography (LC) with fluorimetric detection was evaluated for the preconcentration and determination of thiamine (vitamin B(1)). Derivatization was carried out by chemical oxidation of thiamine with 5 × 10(-5) M ferricyanide at pH 13 to form fluorescent thiochrome. For DLLME, 0.5 mL of acetonitrile (dispersing solvent) containing 90 μL of tetrachloroethane (extraction solvent) was rapidly injected into 10 mL of sample solution containing the derivatized thiochrome and 24% (w/v) sodium chloride, thereby forming a cloudy solution. Phase separation was carried out by centrifugation, and a volume of 20 μL of the sedimented phase was submitted to LC. The mobile phase was a mixture of a 90% (v/v) 10 mM KH(2)PO(4) (pH 7) solution and 10% (v/v) acetonitrile at 1 mL min(-1). An amide-based stationary phase involving a ligand with amide groups and the endcapping of trimethylsilyl was used. Specificity, linearity, precision, recovery, and sensitivity were satisfactory. Calibration graph was carried out by the standard additions method and was linear between 1 and 10 ng mL(-1). The detection limit was 0.09 ng mL(-1). The selectivity of the method was judged from the absence of interfering peaks at the thiamine elution time for blank chromatograms of unspiked samples. A relative standard deviation of 3.2% was obtained for a standard solution containing thiamine at 5 ng mL(-1). The esters thiamine monophosphate and thiamine pyrophosphate can also be determined by submitting the sample to successive acid and enzymatic treatments. The method was applied to the determination of thiamine in different foods such as beer, brewer's yeast, honey, and baby foods including infant formulas, fermented milk, cereals, and purees. For the analysis of solid samples, a previous extraction step was applied based on an acid hydrolysis with trichloroacetic acid. The reliability of the procedure was checked by analyzing a certified reference material, pig's liver (CRM 487). The value obtained was 8.76 ± 0.2 μg g(-1) thiamine, which is in excellent agreement with the certified value, 8.6 ± 1.1 μg g(-1).

Isolation of folate-producing microalgae, from oligotrophic ponds in Yamaguchi, Japan

AIMS

Folate (FA) is a B-vitamin that plays an important role in the prevention of several disorders. Although synthetic FA currently dominates the market, consumers tend to demand natural FA. Because microalgae can produce organic compounds photoautotrophically, we isolated and characterized FA-producing microalgal strains.

METHODS AND RESULTS

To isolate microalgae that produce vitamins de novo, fresh water samples were cultivated in a mineral salts medium without any vitamins. After repeated subculture, 11 isolates were obtained. A biological assay revealed that four isolates accumulated FA at significantly higher levels (15-36 mg kg(-1) in dry biomass) than any known commercial microalgae. Thiamine content of the isolates was also remarkably high (71-90 mg kg(-1) in dry biomass). Phylogenetic studies based on SSU-rDNA suggested that one isolate was Chlamydomonas reinhardtii, while others were likely novel species of Chlorococcum.

CONCLUSION

There are no reports of toxicity associated with Chlamydomonas and Chlorococcum; therefore, the isolates are expected to be safe and useful not only as a promising alternative source of FA and thiamine but also as nutraceuticals for humans and animals.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present results advance our understanding of FA-producing microalgae in aquatic environments and suggest their potentials for application to biotechnological vitamin production.

Characteristics and nutritional and cardiovascular-health properties of seaweeds

While marine algae have traditionally formed part of the Oriental diet, their major use in Western countries has been in the phytocolloid industry. Only a few coastal communities outside Asia have customarily used seaweeds as components of special dishes. Of late, however, seaweeds have gained importance as foodstuffs in Western countries and most recently as components of functional foods because of their high dietary fiber, mineral, vitamin, and phytochemical content, low energy levels, and high concentrations of certain polyunsaturated fatty acids. The present paper reviews the available data for some of the components of the major edible algae and studies several factors that can affect their physiochemical properties (e.g., hydration, water and oil-holding capacity, fermentability, binding capacity, etc.) and, in turn, their nutritional importance. The effects of marine alga consumption on growth and body weight, mineral availability, lipid metabolism, blood pressure, and antioxidant properties are reviewed, together with preliminary data on the effects of some functional foods containing seaweeds on lipid metabolism and gene expression of enzymes engaged in antioxidant protection. This review concludes with some remarks regarding the danger of the improper use of seaweeds in herbal medications. In addition, as the properties of algae are highly dependent on their individual composition, any generalization regarding these properties may be considered misleading and scientifically inappropriate.

Rapid fingerprinting of red wines by MALDI mass spectrometry

Here we report a simple and fast method for wine fingerprinting based on direct matrix-assisted laser desorption/ionization (MALDI) mass spectrometry analysis of different red wine samples, useful for batch-to-batch analysis and for the detection of key compounds even in trace amounts which may vary from vintage to vintage, and from one treatment to another one. A series of 20 samples from different wines were subjected to MALDI mass spectrometry. We found that 2,5-dihydroxybenzoic acid is far superior with respect to all the matrices tested To the best of our knowledge this is the first application of an effective wine profiling not limited to detection of anthocyanins. More than 80 molecular species were detected. Moreover, qualitative and quantitative differences were observed, owing to the nature and relative abundance of different chemical compounds among the wines.