Hydrophilic Vitamin Research Articles

The Efficacy of Vitamins in the Prevention and Treatment of Cardiovascular Disease.

Vitamins are known to affect the regulation of several biochemical and metabolic pathways that influence cellular function. Adequate amounts of both hydrophilic and lipophilic vitamins are required for maintaining normal cardiac and vascular function, but their deficiencies can contribute to cardiovascular abnormalities. In this regard, a deficiency in the lipophilic vitamins, such as vitamins A, D, and E, as well as in the hydrophilic vitamins, such as vitamin C and B, has been associated with suboptimal cardiovascular function, whereas additional intakes have been suggested to reduce the risk of atherosclerosis, hypertension, ischemic heart disease, arrhythmias, and heart failure. Here, we have attempted to describe the association between low vitamin status and cardiovascular disease, and to offer a discussion on the efficacy of vitamins. While there are inconsistencies in the impact of a deficiency in vitamins on the development of cardiovascular disease and the benefits associated with supplementation, this review proposes that specific vitamins may contribute to the prevention of cardiovascular disease in individuals at risk rather than serve as an adjunct therapy.

Diffusion kinetics of vitamin B6 released from bicontinuous and phase-inverted gelatin-agarose co-gels using blending-law modelling

In this study, gelatin and agarose were used as the phase-separated biopolymer system and vitamin B6 served as the diffusant. FTIR analysis confirmed the absence of any chemical interactions between gelatin, agarose, and vitamin B6 under the experimental conditions of this investigation. XRD analysis validated that vitamin B6 was homogenously dissolved in the composite low-solid system. Polarised light microscopy provided insights into the mixture topology and tangible evidence of the formation of bicontinuous and phase-inverted gelatin-agarose composite gels. Small-deformation dynamic oscillation was performed to establish theoretical blending law modelling, which predicted the phase volume and effective concentration of individual components (gelatin and agarose) in their respective domains. Then, a diffusion study was conducted and a novel blending law for diffusion was proposed to estimate the theoretical diffusion coefficient of vitamin B6 in the composite gel by utilizing the effective concentration of each polymer in their phase. Outcomes were compared positively to the observed diffusion coefficient from UV–vis analysis. Results demonstrate that blending-law diffusion theory can be utilised to ascertain the molecular transport of hydrophilic vitamins released from aqueous biopolymer composites.

The importance, prevalence and determination of vitamins B6 and B12 in food matrices: A review.

Vitamins are a vast group of fundamental organic compounds, which are not produced by the human body but are essential for the living organisms' good health. Vitamins B6 and B12 belong to the same group of hydrophilic vitamins. Structurally unrelated, they share the same purpose as essential components for normal cellular operation, growth and development. Vitamin B6 is an enzymatic co-factor that is vital for countless biochemical reactions, and is also important in sugar and fatty acid metabolization. It encompasses three natural and inter-convertible pyridine-derivatives: pyridoxine, pyridoxal and pyridoxamine. Vitamin B12 is a cobalt organometallic complex also indispensable in numerous human physiological functions. It has four bioactive forms: cyanocobalamin, methylcobalamin, hydroxocobalamin and 5'-deoxyadenosylcobalamin, and only a few prokaryotes have the ability to biosynthesize cobalamin. This work reviews the significant aspects of vitamins B6 and B12: their vital roles, consequences of deficit; food sources; and methods of determination and respective matrices, with heavy emphasis on chromatographic techniques developed within the last two decades.

Fabrication and stability of W/O/W emulsions stabilized by gum arabic and polyglycerol polyricinoleate.

In order to study the effect of adsorption of surfactant at the two interfacial layers on emulsion stability, the kinetically stable water-in-oil-in-water (W/O/W) emulsion carriers were prepared using polyglycerol polyricinoleate (PGPR) and gum arabic (GA) as emulsifiers. The relationship between the adsorption of the surfactant and the stability mechanism of the emulsions was elucidated. When the contents of PGPR and GA were low, the interfaces between oil and the inner and outer water phases, respectively, could not be completely covered. However, when the concentration of PGPR was higher than 60 g kg-1 , the excess PGPR was adsorbed on the interface between the oil phase and the outer water phase. When the concentration of GA reached 80 g kg-1 , more GA was adsorbed to the oil-in-water interface. Moreover, the presence of PGPR on the interface could reduce the adsorption capacity of GA. Two types of kinetically stable emulsions were obtained by optimizing the interface composition (60 g kg-1 GA/80 g kg-1 PGPR and 60 g kg-1 PGPR/80 g kg-1 GA). The kinetically stable W/O/W emulsions prepared in this study were successfully used to encapsulate a hydrophilic vitamin (vitamin B12) with an encapsulation efficiency (EE) of 80% and release efficiency (RE) of 95%. The interfacial adsorption GA can accelerate the hydrolysis of fat. Overall, this study provides a new strategy for the preparation of W/O/W emulsions, which might be beneficial for application in food, cosmetic, chemical, and pharmaceutical industries. © 2023 Society of Chemical Industry.

Content and stability of B complex vitamins in commercial cosmetic products.

Individual B vitamins have many favorable effects on the skin and are common cosmetic ingredients. However, their formulation is demanding due to stability issues, which consequently affect the products' quality. We aimed to determine the quality (labeling accuracy, content determination, and content-related quality control) and stability under long-term and accelerated storage conditions of a representative sample of commercial cosmetics containing the most common B vitamins - nicotinamide, dexpanthenol, pyridoxine, and cyanocobalamin. Cyanocobalamin was determined by a previously published stability-indicating HPLC- diode array detector (DAD) method for the simultaneous determination of all hydrophilic vitamins. This method was additionally simplified and adjusted for the time-effective analysis of nicotinamide, dexpanthenol, and pyridoxine. Both methods were properly validated. All labeled B vitamins were present in the 36 tested products, mostly in contents, reported effective on the skin. Thus, a straightforward correlation between vitamin contents and product prices were not observed. The content-related quality control of eight products, which quantitively specify their content, revealed significantly lower nicotinamide contents (47% and 57%) in two products and appropriate or higher nicotinamide (102%-112%) and dexpanthenol (100%-104%) contents than declared in the remaining products. The 6-month long-term and accelerated stability studies demonstrated the products' physical stability, but also revealed dexpanthenol, pyridoxine, and cyanocobalamin degradation, while nicotinamide was mostly stable in the tested products. The obtained results provide an inside into the quality of commercial vitamin B cosmetics and highlight the importance of stability testing in the formulation of quality, efficient, and safe cosmetics.

High-Performance Thin Layer Chromatography Method for Simultaneous Estimation of Water-Soluble Vitamins: Analytical Method Development, Validation and Applications

Vitamins are pivotal ingredients in dietary supplements and nutraceutical products. Since many vitamins are unstable and rapidly degraded, it’s crucial to keep track of their loss throughout processing and storage. Monitoring hydrophilic vitamins may be more crucial than monitoring those lipophilic vitamins because the body does not maintain them as well. There seems to be a need for an all-encompassing method to estimate hydrophilic vitamins. In this study, we have developed a high-performance thin layer chromatography method for estimation of four water-soluble vitamins simultaneously using HPTLC silica-gel 60GF254 plates and ethyl acetate: methanol: hydrochloric acid (0.1N) (8.5:1:0.5 v/v/v) as a mobile phase, which was successfully validated as per the ICH guideline. All the validation parameters were within the acceptable range established by the ICH guideline. The method is precise, reproducible, easy, reliable, and applicable for the estimation of water-soluble vitamins in marketed products. To best of our knowledge, it is simpler, less time-consuming, and more economical than other approaches that have been published for the same purposes

A High-Throughput HILIC-MS-Based Metabolomic Assay for the Analysis of Polar Metabolites.

Mass spectrometry (MS)-based metabolomics approaches have been used for characterizing the metabolite content and composition of biological samples in drug discovery and development, as well as in metabolic engineering, and food and plant sciences applications. Here, we describe a protocol routinely used in our laboratory to conduct a metabolic profiling of small polar metabolites from biological samples. Metabolites can be extracted from each sample using a methanol-based single-phase extraction procedure. The combination of LC-based hydrophilic interaction liquid chromatography (HILIC) and a hybrid quadrupole-time of flight (Q-ToF) mass spectrometer allows the comprehensive analysis of small polar metabolites including sugars, phosphorylated compounds, purines and pyrimidines, nucleotides, nucleosides, acylcarnitines, carboxylic acids, hydrophilic vitamins and amino acids. Retention times and accurate masses of metabolites involved in key metabolic pathways are annotated for routine high-throughput screening in both untargeted and targeted metabolomics analyses.

Effect of soybean lipophilic protein–methyl cellulose complex on the stability and digestive properties of water–in–oil–in–water emulsion containing vitamin B12

This study aimed to evaluate the effects of soybean lipophilic protein (LP)–methyl cellulose (MC) complex on W/O/W emulsions embedded with hydrophilic vitamin B 12 . The LP–MC complex was characterized by emulsifying properties and scanning electron microscopy. W/O/W emulsions were characterized by microdistribution, rheology and stability analysis. The nutrient release behavior of W/O/W emulsions was examined by using in vitro digestion experiments. Microstructural and rheological analyses suggested that the LP–MC complex increased the viscoelasticity of W/O/W emulsions and formed a strong gel network on the droplet surface. W/O/W emulsions exhibited excellent encapsulation efficiency during storage time and showed sustained-release behavior during in vitro digestion when W 1 /O:W 2 was 4:6 and LP:MC was 3:1. These findings contribute to the development of a new W/O/W emulsion system based on the stabilization of the LP–MC complex. They can also be used to provide protection and realize the sustained release of loaded nutrients. • LP–MC complex is first used as a emulsifier of external water phase emulsifier. • LP can be tightly adsorbed on oil droplets. • LP–MC complex can improve the stability of W/O/W emulsion better than Tween 20. • W/O/W emulsion stabilized by LP–MC complex performs well during in vitro digestion.

Smart Vitamin Micelles as Cancer Nanomedicines for Enhanced Intracellular Delivery of Doxorubicin.

Chemotherapy is one of the most effective treatments for cancer. However, intracellular delivery of many anticancer drugs is hindered by their hydrophobicity and low molecular weight. Here, we describe highly biocompatible and biodegradable amphiphilic vitamin conjugates comprising hydrophobic vitamin E and hydrophilic vitamin B labeled with dual pH and glutathione-responsive degradable linkages. Vitamin-based micelles (vitamicelles), formed by self-assembly in aqueous solutions, were optimized based on their stability after encapsulation of doxorubicin (DOX). The resulting vitamicelles have great potential as vehicles for anticancer drugs because they show excellent biocompatibility (>94% after 48 h of incubation) and rapid biodegradability (>90% after 2.5 h). Compared with free DOX, DOX-loaded vitamicelles showed a markedly enhanced anticancer effect as they released the drug rapidly and inhibited drug efflux out of cells efficiently. By exploiting these advantages, this study not only provides a promising strategy for circumventing existing challenges regarding the delivery of anticancer drugs but also extends the utility of current DOX-induced chemotherapy.

The Effects of Commercial Freezing on Vitamin Concentrations in Spinach (Spinacia oleracea)

Commercial food processing has had a significant impact on reducing food spoilage and increasing accessibility to nutrient-dense vegetables. The commercial freezing process, in particular, has given producers the ability to store vegetables with minimized risk of microbial and enzymatic spoilage. Despite the effectiveness of freezing as a preservation method, there is evidence that pre-freezing procedures and prolonged storage can reduce the concentration of vitamins present within certain vegetables. Spinach, one of the most widely produced and consumed vegetables, is particularly susceptible to nutrient loss during the commercial freezing process due to its large surface area and high mineral content. This review summarizes the known effects of the freezing process on hydrophilic and lipophilic vitamins including vitamin C, thiamin, riboflavin, β-carotene, and α-tocopherol. There are two key mechanisms that lead to decreased vitamin concentrations, with the first being attributed to pre-freezing processes including washing and blanching which favours the leaching of hydrophilic vitamins. The second mechanism of vitamin loss is attributed to residual enzymatic activity during storage, where the degree of residual activity can be partially attributed to differences in blanching protocols and freezing practices. Understanding the mechanisms and extent of vitamin loss that the commercial freezing process imparts on leafy green vegetables can help inform future research on improved food processing methods that minimize nutrient loss. Implementing procedures that maintain nutrient retention in frozen vegetables has the potential to assist individuals in achieving their recommended daily intakes of micronutrients.

Synthesis of casein-γ-polyglutamic acid hydrogels by microbial transglutaminase-mediated gelation for controlled release of drugs.

Casein-based hydrogels were reported as biodegradability, biocompatibility, and non-toxic materials that had potential in drug delivery. At present, we prepared two kinds of casein/γ-PGA hybrid hydrogels, 1/5 and 1/9, based on the ratio of γ-PGA to casein. The hydrogels were crosslinked by microbial transglutaminase (MTG), the physicochemical properties of the casein/γ-PGA hydrogels were investigated by scanning electron microscopy (SEM) observation, differential scanning calorimetry (DSC) analysis, texture analysis, swelling ratio test, and stability test. The hydrogels showed a well-interconnected sparse and porous structure. The 1/5 casein/γ-PGA hydrogel was much stable, hard, and cohesive than the 1/9 casein/γ-PGA hydrogel, and the 1/5 casein/γ-PGA hydrogel showed a higher swelling ratio and lower degradation rate. To investigate in vitro release behavior, we chose the hydrophilic vitamin B12 and hydrophobic aspirin as the model drugs incorporated into the casein/γ-PGA hydrogels. The 1/5 casein/γ-PGA hydrogel exhibited a good drug release behavior.

Association of low vitamin B12 in Trigeminal Neuralgia Patients Visiting Peshawar Dental College

Background: Vitamin B12 is also known as cobalamin and is a hydrophilic vitamin, it is involved in metabolism of every cell of the body. It is a cofactor in DNA synthesis RNA, hormones, proteins, and lipids, and in both fatty acid and amino acid metabolism. Low levels of serum vitamin B12 may trigger pain in patients suffering from trigeminal neuralgia. Methylcobalamin, a form of Vitamin B12, protects against neurological diseases and aging. Mauro showed that high doses of methylcobalamin are needed to regenerate neurons as well as the myelin sheath that protects nerve axons and the peripheral nerves.Objective: The prime focus of this study was to report the frequency of low serum Vitamin B12 level in Identified Trigeminal Neuralgia patients visiting Peshawar Dental College and Hospital and to find the effect of gender on low serum vitamin B12 levels.Methods: A total of 90 known trigeminal neuralgia patients seeking treatment at the Department of Oral Medicine, Peshawar Dental College and Hospital were enrolled. All patients were advised to carry out serum Vitamin B12 level in laboratory. Data were analyzed by SPSS version 19. The statistical significance was set up at p <0.05.Results: Out of 90 known trigeminal neuralgia patients, 58.8% were females and 41.1% were males. 43.3% females and 27.0%males had low serum Vitamin B12 levels. No statistical significant difference between gender and low serum vitamin B12 level was found.Conclusions: Study confirms that gender has no effect on low serum levels of B12 in trigeminal neuralgia patients and a highproportion of trigeminal neuralgia patients had a low serum vitamin B12 levels.

The B-complex vitamins related to energy metabolism and their role in exercise performance: A narrative review

ObjectiveThe present review aims to clarify the relationship of thiamine, riboflavin, and niacin to exercise performance. NewsThe B vitamins thiamine (vitamin B1), riboflavin (vitamin B2), and niacin (vitamin B3) are hydrophilic vitamins that play a fundamental role as coenzymes in enzymatic reactions of energy metabolism. The increase in energy demand during physical exercise can alter the requirements for these vitamins. Prospects and projectsThis study is a narrative review which selected and analyzed studies that investigated how the vitamins thiamine, riboflavin, and niacin can affect sports performance in both humans and experimental animal models. ConclusionThe research shows that supplementation with these vitamins does not necessarily produce ergogenic effects. Despite their fundamental roles in anabolic pathways, only the intake of thiamine-derivative substances showed some positive effects on exercise performance and fatigue. Isolated riboflavin supplementation did not show positive effects, while there is evidence that high niacin intake can harm exercise performance. Some studies found an increase in excretion and a decrease in the blood levels of these vitamins after exercise, but the results are inconsistent. However, different pharmacokinetics, doses or dosing frequency, and administration route of the supplemented substances can influence the results. There are few studies of B-vitamins and exercise, and most of them are not recent. New studies, with systematically controlled protocols, are necessary to elucidate the real effects of thiamine, riboflavin, and niacin in exercise performance.

Fish oil-gelatin core-shell electrospun nanofibrous membranes as promising edible films for the encapsulation of hydrophobic and hydrophilic nutrients

In this work, fish oil-gelatin core-shell electrospun nanofibrous membranes (ENMs) were explored as edible films for the encapsulation of hydrophobic fish oil and hydrophilic vitamin C (VC). The results demonstrated that fish oil-VC/gelatin core-shell ENMs could be successfully fabricated by a monoaxial emulsion electrospinning technique. The addition of VC didn't change core-shell structure but increased fragility of nanofibers. Excessive VC/gelatin mass ratios (≥4:20) increased the nanofiber adhesiveness during the storage at room temperature. No obvious chemical interactions occurred among fish oil, gelatin, and VC in the core-shell ENMs. VC addition decreased the loading capacity and had no obvious effects on encapsulation efficiency of fish oil in the ENMs. VC not only prevented lipid oxidation but also converted lipid hydroperoxides to other products during the electrospinning process. Fish oil-VC/gelatin core-shell ENMs were not disintegrated in ultrapure water but were disintegrated into particles in both gastric and intestinal fluids. The fish oil release from fish oil-VC/gelatin core-shell ENMs and disintegrated particles in the simulated intestinal phase of the gastrointestinal tract model and in the simulated intestinal model showed triphasic behaviors. This work provided a potential route to develop functional foods with encapsulation of both hydrophobic and hydrophilic nutrients.

New zwitterionic HP-β-CD-PEI-MPC polymer used as a transdermal penetration enhancer

In this study, a new kind of zwitterionic hydroxypropyl-β-cyclodextrin-polyethyleneimine grafted 2-methylallyloxyethyl phosphorylcholine (HP-β-CD-PEI1800-MPC) transdermal penetration enhancer was successfully synthesized, and its feasibility for promoting transdermal absorption of the hydrophilic drug Vitamin B12 was evaluated. The enhancer was synthesized by epoxy ring-opening and the Michael addition reaction, and its structure was confirmed by nuclear magnetic resonance spectrum (1HNMR). The penetration enhancing effect of HP-β-CD-PEI1800-MPC on hydrophilic vitamin B12 was evaluated by transdermal experience in vitro. A skin irritation experiment and histopathological observations of skin sections with hematoxylin and eosin (H&E) and Masson staining were performed to analyze the safety of HP-β-CD-PEI1800-MPC. A preliminary study was conducted on the promoting mechanism of the transdermal enhancer using laser Raman spectroscopy, ATR-FTIR and DSC. The transdermal depth and distribution of the enhancer in skin were examined by fluorescence labeling. In vitro transdermal permeation was determined by Franz cells, and the cumulative drug content through skin was measured by HPLC. All the data showed that HP-β-CD-PEI1800-MPC could be a safe and effective penetration enhancer for topical drug delivery.

Antioxidant Effect of Vitamins in Olive Oil Emulsion

In this study, water-in-extra virgin olive oil emulsions were enriched with vitamins. Water-in oil emulsions are heterogeneous systems able to solubilize both hydrophilic and hydrophobic compounds. Thus, hydrophilic vitamin C and lipophilic vitamin E were loaded separately or together in emulsion. A suitable emulsion composition was selected after considering different surfactant (mono and diglycerides of fatty acids, E471; sorbitan monooleate, Span 80; polyoxyethylene sorbitan monooleate, Tween 80) and water concentrations. The most appropriate emulsion, for the high stability, resulted the one containing concentrations of Span 80 1% w/w and water 1% w/w. The antioxidant effect of vitamins in emulsions was studied considering the variation of the peroxide values during storage. The oxidation reaction was slowed down in emulsions containing vitamin C, but it was quickened by the loading of vitamin E for its high concentration. In emulsions containing vitamin E, indeed, the peroxide values were higher than in emulsions prepared in the absence of vitamins or in oil. The antioxidant activity generated by the co-loading of vitamin C and E was very effective to the point that in presence of high amounts of vitamins the peroxide values did not change in about 40 days of storage, due to the vitamin E regeneration by vitamin C.

Physical Properties of an Ionic Liquid Composed of Two Water-Soluble Vitamins and Enhanced Skin Permeation of Both Vitamins

A highly viscous substance was prepared by evaporating an ethanol solution containing two hydrophilic vitamins; vitamin C, and vitamin B6. The viscous substance and physical mixture of the two vitamins were tested using a differential scanning calorimeter and an X-ray diffractometer. The highly viscous substance was found to be a liquid crystal (LC) made of these two hydrophilic vitamins. Determination by proton nuclear magnetic resonance measurement suggested that intramolecular hydrogen bonding in vitamin B6 was eliminated by the LC formation. This LC compound showed high solubility in 1,3-butanediol (almost 87%). Much higher skin permeation of both vitamin C and B6 was also observed from the LC compound than that from the physical mixture. The present LC compound containing vitamin C and vitamin B6 may be useful for pharmaceutical and cosmeceutical applications.

Bio-metal-organic frameworks for molecular recognition and sorbent extractionof hydrophilic vitamins followed bytheir determination usingHPLC-UV.

A bio-metal-organic framework (bio-MOF) derived from the amino acid L-serine has been prepared in bulk form and evaluated as sorbent for the molecular recognition and extraction of B-vitamins. The functional pores of bio-MOF exhibit high amounts of hydroxyl groups jointly directing other supramolecular host-guest interactions thus providingthe recognition of B-vitamins in fruit juices and energy drinks. Single-crystal X-ray diffraction studies reveal the specific B-vitamin binding sites and the existence of multiple hydrogen bonds between these target molecules and the framework. It offered unique snapshots to accomplish an efficient capture of these solutes in complex aqueous matrices. Four B-vitamins (thiamin, nicotinic acid, nicotinamide, and pyridoxine) were investigated. They were eluted from the sorbent with phosphate buffer at pH7 and analyzed by HPLC with UV detection. The sorbent was compared with commercial C18 cartridges. Following the procedure, acceptable reproducibility (RSD values < 14%) was achieved, and the detection limits were in the range 0.4 to 1.4ngmL-1. The method was applied to the analysis of energy drink and juice samples and the recoveries were between 75 and 123% in spiked beverage samples. Graphical abstractA bio-MOF as SPE sorbent was prepared and applied to the extraction of B-vitamins in fruit juices and energy drinks.

In vitro ispitivanje antioksidativne aktivnosti preparata ruzmarinske kiseline i meda

Disrupted balance between free radicals and antioxidants leads to a pathophysiological state of oxidative stress, which is the underlying cause of many diseases. Since some synthetic antioxidants show some potentially adverse effects, many studies aim to find natural antioxidants. Secondary plant metabolites, such as polyphenols, phenolic acids, which include rosmarinic acid, terpenes and terpenoids have antioxidative properties and can be found in different hydrosols and honey. The aim of this study is to evaluate the in vitro antioxidative activity of the supplement based on hydrosol mixture, rosmarinic acid and honey. A series of diluted (100%, 50%, and 25%) supplements were added to the serum pool, collected from healthy donors. A second series of samples was prepared with the same amounts of supplement and addition of tert-Butyl hydroperoxide (TBH) as a prooxidant. Alongside these samples, sera samples with Trolox (hydrophilic vitamin E analog) and Trolox with TBH were prepared. All these samples were tested for the following oxidative stress parameters: total antioxidative status (TAS), paraoxonase-1 (PON-1), total sulfhydryl groups content (SHG), total oxidative status (TOS), prooxidative-antioxidative balance (PAB) and advanced oxidation protein products (AOPP). TAS/TOS ratio was calculated as a quantitative measurement of antioxidative and oxidative substances ratio in the serum. Antioxidative parameters TAS, SHG, TAS/TOS ratio and prooxidant/antioxidant balance parameter PAB, were not significantly different for the supplemened samples with and without the addition of TBH, which indicates that the supplement keeps its antioxidative properties, despite the addition of TBH. The supplement showed significant antioxidative properties as a result of the synergistic effect of rosmarinic acid, terpenes, and terpenoids from hydrosols and polyphenols and other antioxidant substances from honey.

Investigation of Active and Inactivated Yeast Cells by Scanning Electrochemical Impedance Microscopy

AbstractScanning electrochemical microscopy (SECM), electrochemical impedance spectroscopy (EIS) and scanning electrochemical impedance microscopy (SEIM) were used to investigate electrochemical activity of active and inactivated yeast Saccharomyces cerevisiae cells. SEIM experiment was performed using a unique electrochemical impedance spectrometer with a fast Fourier transform (FFT‐EIS) function, which enabled simultaneously perturb/evaluate electrochemical system at 50 frequencies. This allowed very quick observing the differences between impedance spectra, which were taken every few seconds. Therefore, we were able to apply SEIM for relatively fast determination of electrochemical impedance dependence on the distance between ultramicroelectrode (UME) and surface modified by immobilized yeast cells. It was determined that electrochemical activity and ‘breathing’ (a consumption of dissolved oxygen) of yeast can be electrochemically observed when the distance between UME and surface of yeast cells is in the range from 0 μm to 25 μm. Therefore, 25 μm is the maximum distance suitable for efficient investigation of yeast cell activity when experiments are performed in FFT‐SEIM mode. Charge transfer resistance of active and inactivated yeast cells was determined using EIS. It was calculated that charge transfer resistance of active yeast cells is 1.5 times lower than that of inactivated yeast cells. Lipophilic vitamin K3 (Vit‐K3) and hydrophilic vitamin K1 (Vit‐K1) were mixtured and used as redox mediators for charge transfer from yeast cells.