Analysis of Vitamin B12 in Food by Silica Gel 60 TLC and Bioautography with Vitamin B12-Dependent Escherichia coli 215

SERS determination of sodium saccharin content on the tipping paper of cigarettes using AgNP substrates prepared with a USB-power supply device

A novel magnetic agitating heater powered by a USB port has been developed and applied to synthesize silver colloid substrate for surface-enhanced Raman scattering (SERS) detection of sodium saccharin content on the tipping paper of cigarettes. The heater device allows the convenient synthesis of the Ag colloid, and the reaction can be completed on-site in 15 min under mild conditions. The on-site synthesis of SERS substrate effectively avoided the need for storage and concerns regarding the poor stability and short lifespan of colloid substrates. The results demonstrated that the substrate obtained with the device could achieve SERS detection of Rhodamine 6G (R6G) at as low as 10-9 mol L-1 while maintaining a stable intensity with a relative standard deviation (RSD) of 5.52% (n = 5). Using the prepared substrate at the optimal conditions, the limit of detection of sodium saccharin (SS) was 1 mg L-1. By introducing an internal standard KSCN, a linear relationship was observed between the relative intensity at 708 cm-1 and the concentration of the SS in a range of 20-100 mg L-1 (R2 = 0.98). With the developed method, SS was directly extracted from the cigarette paper by immersing it in water, and the extracted solution was subsequently detected. The quantitative spike-recoveries were in the range of 95.5-116.7%, with RSD between 2.3-12.6%. The whole detection procedure including the on-site substrate preparation, took only about 30 min. This work opens new avenues for colloidal synthesis, and the detection method of SS on the cigarette paper also holds great promise in food safety applications.

Production and characterization of cyanocobalamin-enriched tomato (Solanum lycopersicum) fruits grown using hydroponics

BACKGROUND

Vitamin B₁₂ is an essential vitamin that is absent in plant-derived foods such as fruits and vegetables. This can result in an increased risk of developing vitamin B₁₂ deficiency in strict vegetarians (vegans). There are several studies that have aimed to enhance nutrients in food crops. The purpose of the present study was to fortify tomato fruits with vitamin B₁₂ (or cyanocobalamin).

RESULTS

Tomato plants were grown for 70 days in hydroponic culture pots and treated with 5 μm of cyanocobalamin on days 1-24 after the fruiting, and then harvested for tomato fruits. The ripened tomato fruits contained 4.0 × 10^-7  g of cyanocobalamin per 100 g of dry weight and showed a significant increase in glucose and lycopene levels.

CONCLUSION

The present study highlights the use of a cyanocobalamin-supplementation system for the production of B₁₂ fortified tomato fruits that can help prevent B₁₂ deficiency in vegetarians. © 2022 Society of Chemical Industry.

Food Additives (Hypochlorous Acid Water, Sodium Metabisulfite, and Sodium Sulfite) Strongly Affect the Chemical and Biological Properties of Vitamin B12 in Aqueous Solution

Food additives, such as hypochlorous acid water, sodium metabisulfite, and sodium sulfite, strongly affect the chemical and biological properties of vitamin B₁₂ (cyanocobalamin) in aqueous solution. When cyanocobalamin (10 μmol/L) was treated with these compounds, hypochlorous acid water (an effective chlorine concentration of 30 ppm) rapidly reacted with cyanocobalamin. The maximum absorptions at 361 and 550 nm completely disappeared by 1 h, and vitamin B₁₂ activity was lost. There were no significant changes observed in the absorption spectra of cyanocobalamin for 0.01% (w/v) sodium metabisulfite; however, a small amount of the reaction product was formed within 48 h, which was subsequently identified as sulfitocobalamin through high-performance liquid chromatography. Similar results were shown for sodium sulfite. The effects of these food additives on the vitamin B₁₂ content of red shrimp and beef meats were determined, revealing no significant difference in vitamin B₁₂ content of shrimp and beef meats with or without the treatment even in hypochlorous acid water. The results suggest that these food additives could not react with food vitamin B₁₂ in food, as most of this vitamin present in food is its protein-bound form rather than the free form.

Vitamin B12 among Vegetarians: Status, Assessment and Supplementation

Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.

Functional and structural characteristics of methylmalonyl-CoA mutase from Pyrococcus horikoshii

Methylmalonyl-CoA mutase (MCM) requires 5′-deoxyadenosylcobalamin (AdoCbl) as a cofactor and is widely distributed in organisms from bacteria and animals. Although genes encoding putative MCMs are present in many archaea, they are separately encoded in large and small subunits. The large and small subunits of archaeal MCM are similar to the catalytic and AdoCbl-binding domains of human MCM, respectively. In Pyrococcus horikoshii OT3, putative genes PH1306 and PH0275 encode the large and small subunits, respectively. Because information on archaeal MCM is extremely restricted, we examined the functional and structural characteristics of P. horikoshii MCM. Reconstitution experiments using recombinant PH0275 and PH1306 showed that these proteins assemble in equimolar ratios and form of heterotetrameric complexes in the presence of AdoCbl. Subsequent immunoprecipitation experiments using anti-PH0275 and anti-PH1306 antibodies suggested that PH0275 and PH1306 form a complex in P. horikoshii cells in the presence of AdoCbl.

Vitamin B12[c-lactone], a biologically inactive corrinoid compound, occurs in cultured and dried lion's mane mushroom (Hericium erinaceus) fruiting bodies

This study determined the vitamin B12 content of the edible medicinal mushroom Hericium erinaceus, lion's mane mushroom fruiting body, using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Trace levels (0.04-0.36 μg/100 g dry weight) of vitamin B12 were found in most of the dried mushroom samples, and two samples contained slightly higher levels (0.56 and 1.04 μg/100 g dry weight, respectively) of vitamin B12. We purified the corrinoid compounds from the extracts of dried lion's mane mushroom fruiting bodies using an immunoaffinity column and identified them as vitamin B12 or vitamin B12[c-lactone] (or both) based on LC/ESI-MS/MS chromatograms. This is the first report on an unnatural corrinoid, vitamin B12[c-lactone], occurring in foods. Vitamin B12[c-lactone] was simple to produce during incubation of authentic vitamin B12 and chloramine-T, an antimicrobial agent, at varying pH values (3.0-7.0) and was completely inactive in the vitamin B12-dependent bacteria that are generally used in vitamin B12 bioassays.

Characterization of vitamin B₁₂compounds in the wild edible mushrooms black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius)

This study determined the vitamin B₁₂ content of six wild edible mushrooms which are consumed by European vegetarians. Zero or trace levels (0.01-0.09 µg/100 g dry weight) of vitamin B₁₂ were determined in porcini mushrooms (Boletus spp.), parasol mushrooms (Macrolepiota procera), oyster mushrooms (Pleurotus ostreatus), and black morels (Morchella conica). By contrast, black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius) mushrooms contained considerable levels (1.09-2.65 µg/100 g dry weight) of vitamin B₁₂. To determine whether C. cornucopioides or C. cibarius contained vitamin B₁₂ or other corrinoid compounds that are inactive in humans, we purified a corrinoid compound using an immunoaffinity column and identified it as vitamin B₁₂ based on LC/ESI-MS/MS chromatograms.

Biologically active vitamin B12 compounds in foods for preventing deficiency among vegetarians and elderly subjects

The usual dietary sources of vitamin B12 are animal-source based foods, including meat, milk, eggs, fish, and shellfish, although a few plant-based foods such as certain types of dried lavers (nori) and mushrooms contain substantial and considerable amounts of vitamin B12, respectively. Unexpectedly, detailed characterization of vitamin B12 compounds in foods reveals the presence of various corrinoids that are inactive in humans. The majority of edible blue-green algae (cyanobacteria) and certain edible shellfish predominately contain an inactive corrinoid known as pseudovitamin B12. Various factors affect the bioactivity of vitamin B12 in foods. For example, vitamin B12 is partially degraded and loses its biological activity during cooking and storage of foods. The intrinsic factor-mediated gastrointestinal absorption system in humans has evolved to selectively absorb active vitamin B12 from naturally occurring vitamin B12 compounds, including its degradation products and inactive corrinoids that are present in daily meal foods. The objective of this review is to present up-to-date information on various factors that can affect the bioactivity of vitamin B12 in foods. To prevent vitamin B12 deficiency in high-risk populations such as vegetarians and elderly subjects, it is necessary to identify plant-source foods that contain high levels of bioactive vitamin B12 and, in conjunction, to prepare the use of crystalline vitamin B12-fortified foods.

Production and characterization of cyanocobalamin-enriched lettuce (Lactuca sativa L.) grown using hydroponics

When lettuces (Lactuca sativa L.) grown for 30 days in hydroponic culture were treated with various concentrations of cyanocobalamin for 24 h, its content in their leaves increased significantly from nondetectable to 164.6 ± 74.7 ng/g fresh weight. This finding indicated that consumption of only two or three of these fresh leaves is sufficient to meet the Recommended Dietary Allowance for adults of 2.4 μg/day. Analyses using a cobalamin-dependent Escherichia coli 215 bioautogram and LC/ESI-MS/MS demonstrated that the cyanocobalamin absorbed from the nutrient solutions by the leaves did not alter any other compounds such as coenzymes and inactive corrinoids. Gel filtration indicated that most (86%) of the cyanocobalamin in the leaves was recovered in the free cyanocobalamin fractions. These results indicated that cyanocobalamin-enriched lettuce leaves would be an excellent source of free cyanocobalamin, particularly for strict vegetarians or elderly people with food-bound cobalamin malabsorption.

Broth from canned clams is suitable for use as an excellent source of free vitamin B12

Vitamin B(12) was assayed and characterized in the broth of canned clams (boiled plain). The broth contained considerable amounts of vitamin B(12) (2.7-14.1 μg/100 g, 1.3-6.7 μg/can). HPLC and LC/ESI-MS/MS chromatograms demonstrated that the clam broth contained true vitamin B(12). Gel filtration experiments indicated that most (72%) of the vitamin B(12) found in the broth was recovered in free vitamin B(12) fractions. These results indicate that the clam broth would be suitable for use an excellent source of free vitamin B(12) for elderly persons with food-bound vitamin B(12) malabsorption.

Occurrence of pseudovitamin B12 and its possible function as the cofactor of cobalamin-dependent methionine synthase in a cyanobacterium Synechocystis sp. PCC6803

To clarify the physiological function of pseudovitamin B(12) in cyanobacteria, we determined pseudovitamin B(12) contents and cobalamin-dependent methionine synthase activity in Synechocystis sp. PCC6803 grown under CoSO(4)-sufficient and -limited conditions. Pseudovitamin B(12) and cobalamin-dependent methionine synthase activity (0.8 nmol/min/mg protein) were found in a homogenate of the Synechocystis cells grown for 10 d in the CoSO(4)-sufficient medium. The cellular pseudovitamin B(12 )contents increased significantly at the early logarithmic growth phase and thereafter decreased rapidly at the stationary phase; a similar fluctuation pattern was shown in the cobalamin-dependent methionine synthase activity. Although the CoSO(4)-limited conditions did not reduce the cell growth, pseudovitamin B(12) contents and methionine synthase activity decreased significantly in the limited cells relative to the sufficient cells. These results indicate that the cyanobacterium Synechocystis sp. PCC6803 can synthesize pseudovitamin B(12) de novo and utilize it as the cofactor for cobalamin-dependent methionine synthase.

Characterization of vitamin B12 compounds from Korean purple laver (Porphyra sp.) products

Vitamin B(12) contents of various Korean purple laver products were determined with the microbiological vitamin B(12) assay method. Although a substantial amount (133.8 microg/100 g) of vitamin B(12) was found in dried purple laver, seasoned and toasted laver products contained lesser vitamin B(12) contents (about 51.7 microg/100 g). The decreased vitamin B(12) contents in the seasoned and toasted laver products, however, were not due to loss or destruction of vitamin B(12) during the toasting process. Silica gel 60 thin layer chromatography-bioautogram analysis indicated that all Korean laver products tested contain true vitamin B(12), but not inactive corrinoid compounds. In vitro gastrointestinal digestion experiments indicated that digestion rate of vitamin B(12) from the dried Korean purple laver was estimated to be 50% under pH 2.0 conditions (as a model of normal gastric function). These results suggest that Korean purple laver products would be excellent vitamin B(12) sources for humans, especially vegetarians.