Dietary Supplement Samples Research Articles

Fast spectroscopic and multisensor methods for analysis of glucosamine and hyaluronic acid in dietary supplements

There is a lack of fast and inexpensive analytical methods for quantification of key ingredients in dietary supplements. Here we explore the potential of near infrared (NIR) spectrometry, attenuated total reflection infrared (ATR-IR) spectrometry and potentiometric multisensor system (MSS) in quantitative determination of glucosamine and hyaluronic acid in commercial samples of dietary supplements. All three methods have demonstrated their applicability for this task when combined with chemometric data processing. Principal Component Analysis (PCA) revealed similarities across the three techniques, indicating the presence of distinct sample composition. Partial least squares (PLS) models were constructed for glucosamine and hyaluronic acid quantification. The root mean square error of cross validation (RMSECV) for glucosamine quantification varied between 7.7 wt% and 8.9 wt%. NIR spectrometry has demonstrated the best accuracy for hyaluronic acid (RMSECV = 9.9 wt%), while ATR-IR and MSS yielded somewhat worse performance with RMSECV values of 12.1 and 11.3 wt%, respectively. The findings of this study indicated that NIR, ATR-IR and MSS exhibit reduced accuracy in comparison to complex and high-precision analytical techniques. However, they can be employed for the rapid, semi-quantitative evaluation of glucosamine and hyaluronic acid in dietary supplements, with the possibility of integration into routine quality control procedures.

Evaluation of three ginsenoside content in raw materials and ginseng-containing supplements

Ginseng (Panax ginseng) is a traditional medicinal herb commonly used in traditional medicine. It exhibits various beneficial health effects, including tonic, antioxidant, antiinflammatory, antibacterial, cardiovascular disease prevention, anti-obesity, diabetes regulation, central nervous system modulation, and anti-cancer properties. Red ginseng, a processed form of ginseng, is noted for its enhanced pharmacological effects and reduced side effects compared to fresh ginseng. The quality of ginseng and red ginseng is largely determined by the content and ratio of three key ginsenosides: Rb1, Rg1, and Rg3. This study utilized the liquid chromatography with tandem mass spectrometry (LC-MS/MS) method to simultaneously analyze the levels of these three ginsenosides in 16 samples of raw materials extracted from ginseng or red ginseng and 55 dietary supplements containing ginseng or red ginseng extract in Vietnam. The results demonstrated significant variability in the content and ratio of the three ginsenosides across the raw material and dietary supplement samples.

Study on determination of cynarin in dietary supplement containing artichoke by high performance liquid chromatography

There has been no announcement on the standardization and testing of cynarin in dietary supplements containing artichokes in Vietnam. The high-performance liquid chromatography (HPLC) method was developed to determine cynarin in dietary supplements containing artichokes. The sample was extracted twice with 80% methanol solvent and ultrasonicated at 50°C for 20 minutes. Centrifuge at 6000 rpm for 5 minutes, filter, and inject into HPLC system with XBridge C18 column (250 mm x 4,6 mm, 5 µm) and corresponding pre-column, mobile phase consisting of two solvents phosphoric acid 0,1% and acetonitrile eluted according to gradient program, flow rate 1mL/min, detection wavelength 322nm. The calibration curves for cynarin had R2 = 1, and the validation parameters met AOAC standards. The method detection limits and the limit of quantification were 3.00 mg/kg and 10.0 mg/kg, respectively. The validated method was applied to determine cynarin in 15 dietary supplement samples. The content of cynarin varied depending on the manufacturer

Mercury Levels in Selected Medicines and Dietary Supplements in Poland.

Current trends are promoting youth, beauty, health, and fitness. Individuals often seek out remedies, such as medicines or dietary supplements (DS), to achieve these goals. However, highly processed foods, chronic stress, and environmental pollution contribute to the development of civilization diseases. The aim of this study was to evaluate the mercury (Hg) content in medicines and DS that are available in Poland. A total of 139 preparations were tested (75 drugs, 64 DS). The medicines contained preparations belonging to antibacterial, antiviral, antifungal; analgesic, antipyretic, and anti-inflammatory; heart and blood vessel disease preventatives; respiratory tract infections treatment; diuretics; aiding digestion; supplements; antidiarrhoeals; anti-allergics; anti-rheumatics; antibiotics; and others. The tested dietary supplements had an effect on the following: improve the condition of skin, hair, and nails; vitamins; minerals; probiotics; weight loss; special for women; and others. The Hg content of the samples was determined using atomic absorption spectrometry (AAS). The Hg content of all the preparations varied widely (0.1-57.4µg/kg), with a median Hg concentration of 1.2µg/kg. The median Hg concentration for medicines was 0.8µg/kg, prescription medicines having higher Hg concentrations (0.9µg/kg) than over-the-counter (OTC) drugs (0.5µg/kg). For DS, the Hg content was found to be higher than for drugs, at 2.0µg/kg. The herbal preparations showed the highest Hg content among the individual DS groups (3.4µg/kg). The Hg concentrations in the tested drug and DS samples did not exceed acceptable standards. However, if multiple pharmaceutical preparations are taken simultaneously over a long period of time, and there is existing environmental exposure, there is a possibility of Hg concentration accumulation and adverse health effects.

O-Phthalaldehyde Derivatization for the Paper-Based Fluorometric Determination of Glutathione in Nutritional Supplements.

Herein, a new, direct paper-based fluorimetric method is described for the quantitative determination of glutathione (GSH) molecules in nutritional supplements. Briefly, the proposed analytical method is based on the fluorescence emission resulting from the direct and selective chemical reaction of GSH molecules with the derivatization reagent that is o-phthalaldehyde (OPA) in acidic conditions at room temperature. The intensity of the emitted fluorescence on the surface of the analytical paper devices after irradiation with a lamp at 365 nm is proportional to the concentration of GSH and is measured using a smartphone as the detector. This methodology, which is suitable for measurements in laboratories with limited resources, does not require specialized instrumentation or trained personnel. The protocol governing the proposed method is simple and easily applicable. Essentially, the chemical analyst should adjust the value of pH on the surface of the paper by adding a minimal amount of buffer solution; then, after adding a few microliters of the derivatization reagent, wait for the surface of the paper to dry and, finally, add the analyte. Subsequently, the irradiation of the sensor and the measurement of the emitted fluorescence can be recorded with a mobile phone. In the present study, several parameters affecting the chemical reaction and the emitted fluorescence were optimized, the effect of interfering compounds that may be present in dietary supplements was examined, and the stability of these paper sensors under different storage conditions was evaluated. Additionally, the chemical stability of these paper devices in various maintenance conditions was studied, with satisfactory results. The detection limit calculated as 3.3 S/N was 20.5 μmol L-1, while the precision of the method was satisfactory, ranging from 3.1% (intra-day) to 7.3% (inter-day). Finally, the method was successfully applied to three different samples of dietary supplements.

Microscopy, HPTLC, and LC-DAD-Q-ToF validation of nut-based weight-loss dietary supplements, Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut)

Aleurites moluccanus (candlenut) and Bertholletia excelsa (Brazil nut) are marketed as dietary supplements for weight loss. These dietary supplements have been found to sometimes be adulterated with toxic nuts/seeds from Cascabela thevetia, commonly known as yellow oleander or lucky nut. This study emphasizes the key identification parameters to differentiate the genuine and adulterated nuts. Samples were obtained from authenticated sources of the nuts and from commercial sources of dietary supplements. This study examined 38 samples, including voucher and commercial samples. All eight commercial candlenut dietary supplement samples were adulterated. Additionally, two samples sold as Brazil nuts were also found to be adulterated. Other nuts were screened for the presence of Cardiac Glycosides, but none were found to be positive. The presence of yellow oleander was confirmed in all commercial dietary supplement samples marketed as candlenut as well as in commercial samples of Brazil nut. This study provides simple key identification characters using micro-morphology and histochemical localization of cardiac glycosides in the commercial nuts, HPTLC fingerprints, and LC-DAD-Q-ToF analytical parameters to detect and identify adulteration in commercial products.

HPTLC monitoring of illegal antihypertensive and antihistamine compounds in herbal products from the Vietnam market

Given the growing craze for dietary supplements, it is essential to critically examine the safety concerns surrounding their usage. There have been several cases of contaminated food-related mishaps in spite of numerous rules and laws in existence. We thus made an effort to find the existence of five antihistamines and four hypertensive in herbal items from the Vietnamese market, given the rising severity of this issue. High-performance thin-layer chromatography (HPTLC) was used to screen 32 samples, which were typical of the many kinds of herbal products. The investigation included both intra- and inter-day precision as well as repeatability. For all analytes, the devised technique was proven to be exact, with %RSD lower than 6%. The LOD and LOQ of nine compounds were determined to be in the range of 0.15–0.30 mg/g and 0.50–1.00 mg/g, respectively (solid matrix sample); 0.075–0.150 mg/g; and 0.25–0.50 mg/g (liquid matrix sample). The intra-day variation's percentage RSD varies from 1.40 to 5.10. Nonetheless, the inter-day variation's percentage RSD fell between 3.10 and 6.60. As a result, the procedure may be used to analyze herbal dietary supplement samples that are in circulation in order to quality control the herbal products on the Vietnamese market.

Quantification of lactoferrin in dietary supplements using a Heparin affinity clean-up column by HPLC PDA detector

The use of dietary supplements containing lactoferrin is a growing trend. As a result, there is a need for a simple and reliable analytical method to determine the content of lactoferrin in these supplements to ensure food quality. In this study, an HPLC method was developed and validated for determining lactoferrin in dietary supplements using a HiTrap Heparin clean-up column in combination with HPLC. The study involved selecting optimal conditions for extracting lactoferrin from the sample matrix, followed by chromatography conditions using a C4 column (150 mm × 4.6 mm, 3.5 µm). The limit of detection (LOD) and limit of quantification (LOQ) were determined, with the achieved values being 1.2 mg/100g and 4.0 mg/100g, respectively. The method has shown good recovery (99.5–103.4%) and precision (RSD 1.76–3.44%), meeting the method performance requirements outlined in AOAC SMPR 2020.005. The validated method was applied to determine the contents of lactoferrin in dietary supplement samples.

Quantification of elements in dietary supplements by total reflection x‐ray fluorescence and inductively coupled plasma optical emission spectrometry

AbstractThe main purpose of this study was the comparison of the results of quantification obtained via different sample preparation approaches such as microwave‐assisted wet digestion (MAWD) and suspension preparation. Two total reflection x‐ray fluorescence (TXRF) spectrometers equipped with Mo x‐ray tubes were used to compare results obtained via two different paths of sample preparations which would further be compared to the conventional way of analysis by inductively coupled plasma optical emission spectrometry (ICP‐OES) including MAWD. Three dietary supplement samples with different sets and concentrations of elements were analyzed. The benefits and limitations of the simplified path of sample preparation were highlighted. A round‐robin test between TXRF and ICP‐OES was discussed. Accuracy as the percentage of recovery in all measurements ranged from 80 to 120. Precision for all results did not exceed 8% for TXRF and 5% for ICP‐OES. Limits of quantification by TXRF are ranged from 1 to 0.01 mg/pill for different elements. It was shown that suspension preparation of samples might be a useful response to increasing demand for quality control of dietary supplements since it is less time consuming and cost efficient.

Detection of L-lysine in food supplement based on amperometric biosensors

L-lysine is an essential amino acid not synthesized by the body and is used as a nutritional supplement, and is considered an index of the nutritional quality of foodstuffs. The level of L-lysine consumption depends on age, where an imbalance in L-lysine levels can cause certain disease conditions. This study identified the effects of L-lysine contained in food supplements using the yeast-based amperometric biosensor Saccharomyces cerevisiae, which measures dissolved oxygen (DO) levels due to cellular respiration of yeast with an analyte assay sample. The measurements were made by calibrating pure L-lysine at 100, 200 and 300 mM concentrations. The results show that the higher the concentration of L-lysine, the smaller the level of DO remaining detected, where the percentage range of DO is 13.47% - 26.02%. The dietary supplement sample test, namely Curcuma Plus, has an error of 1.01% which states that the biosensor used can detect L-lysine levels in samples with high sensitivity and selectivity and can be applied to the food and health industries. The measurement results are clustered using Principal Component Analysis (PCA) to see the resulting clusters and data patterns.

Paper-based fluorescent sensors from quinoline ligands for distance-based quantification of Zn2+

A series of aminoquinoline derivatives with different N-alkyl substituents were synthesized and used in the development of paper-based fluorescent sensors. In aqueous solutions, the quinoline ligands show strong green fluorescence selectively upon binding to Zn2+ that is clearly observed by naked eyes under blacklight illumination. The paper-based sensors were prepared by depositing the amidoquinoline derivatives in wax-printed channels on filter paper. Developing of Zn2+ samples, deposited below the ligand spots, with an aqueous buffer solution creates green fluorescent lines suitable for distance measurement. The ligands with a tertiary amino group showed better-defined fluorescent lines than those of ligands containing primary and secondary amino groups. The length of the fluorescent lines increases linearly with the amounts of Zn2+ in the range of 2.5–80 nmol that can be easily determined by naked-eye observation or an image processing software. The increase in hydrophobicity of the ligands results in a wider dynamic concentration range of the detection. The paper-based sensor can accurately and conveniently quantify Zn2+ in drinking water, dietary supplement, and fertilizer samples.

Determination of aristolochic acid using a piezoelectric immunosensor based on magnetic carbon nanocomposites

A technique for the determination of aristolochic acid (AA) in food products using a piezoelectric immunosensor is presented. Magnetic carbon nanocomposites (MCNC) were used as the recognition layer of the sensor, on the surface of which protein conjugates of AA were immobilized. Abstract-Methods for the synthesis of Fe3O4 magnetic nuclei and their attachment to the surface of multi-walled carbon nanotubes (CNTs) have been studied. Using IR spectrometry, it was found that the formation of the recognition layer of the sensor occurs due to the formation of covalent bonds between the amino groups of AA conjugates and carboxyl groups of CNTs. The concentrations of protein conjugates based on ovalbumin (OVA) and bovine serum albumin (BSA) (0.3 and 0.2 mg/ml) and the degree of antibody dilution (0.25) were determined, which provide optimal characteristics of the piezoelectric immunosensor. The metrological characteristics of the method for determining AA have been established. The range of determined concentrations of AA and the limit of detection when using a piezoelectric immunosensor with a recognition layer based on MUNA/AA-OVA and MUNA/AA-BSA are (ng/ml): 50 – 400 and 10; 100 – 300 and 50, respectively. The sensor has been tested in the determination of AA in samples of Chinese herbal tea and dietary supplements for weight loss. No acid was found in tea, and in dietary supplements, the acid content is 3.2 μg/g.

Using stable carbon isotope ratio analysis to detect adulteration in red yeast rice dietary supplements

Red yeast rice (RYR) is marketed as a dietary supplement because it contains natural 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), including monacolin K. However, there is concern that some RYR supplements may be adulterated with the pharmaceutical drug lovastatin to enhance health claims. We have developed an optimized method to isolate monacolin K/lovastatin from complex RYR dietary supplement matrices to then test for adulteration in RYR supplements using stable carbon isotope (δ13C) analysis. Samples were initially screened for monacolin K/lovastatin using liquid chromatography with mass spectrometric detection (LC-MS). To ensure the extraction process did not affect the measured isotopic values (i.e., isotopic fractionation effects), neat lovastatin standards were spiked into two types of blank RYR matrices (powder and gel). The monacolin K/lovastatin peaks were detected using high performance liquid chromatography with ultraviolet detection (HPLC-UV) and isolated using fraction collection. Residual matrix components were removed from targeted fractions by solid phase extraction (SPE) using graphitized carbon black cartridges. The resulting isolates were then analyzed using elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) to measure δ13C values. The δ13C values of the extracted lovastatin standards were compared to their respective neat lovastatin δ13C values and demonstrated negligible isotopic fractionation effects. Using this optimized clean up method and carbon isotope analysis, thirty-one samples were screened. Eight RYR dietary supplement samples had >0.8 mg/g of monacolin K/lovastatin, our minimum threshold for analyzing samples using this method. Four of these eight samples had δ13C values greater than −28.3‰, a previously proposed cutoff value for natural monacolin K, indicating likely adulteration. Additionally, five RYR powder samples were analyzed as part of a collaborative study using in-house methods from two laboratories and the data shows acceptable agreement in the δ13C values of monacolin K/lovastatin (differences ranging from ±0.02‰ to ±0.76‰). This optimized method represents a robust, reproducible procedure for detecting lovastatin adulteration in dietary supplements with minimal isotopic fractionation.

Determination of Essential and Non-Essential Elements in Dietary Supplements by Microwave-Induced Plasma Optical Emission Spectrometry: Method Development and Study of Non-Spectral Interferences

Dietary supplements have been used to overcome nutritional deficiencies and the knowledge concerning essential and non-essential elements is an important issue. In this work the suitability of microwave-induced plasma optical emission spectrometry (MIP OES) for the determination of essential and non-essential elements in dietary supplements was evaluated. Twelve dietary supplement samples of several classifications (vitamins/minerals, minerals, amino acids, and botanicals) were digested in their whole form for determination of essential (Ca, Co, Cu, Fe, K, Mg, Mn, Mo, Na, and Zn) and non-essential (Ag, Al, B, Ba, Be, Cd, Cr, La, Li, Ni, Pb, Sr, and V) elements by MIP OES. Potential non-spectral interferences by common concomitants (C, S, K, Na, and Ca) were evaluated, as well as those by residual acidity of digests. The study of non-spectral interferences showed that a signal suppression effect is observed with higher concentrations of Ca, Na, and K. Relatively good robustness was observed considering the presence of C and S, as well as residual HNO3. The limits of quantification (LOQs) were dependent on the sample mass used for decomposition (from 0.6 to 1.6 g in the commercial product) and on the minimum dilution factor. From the results, there was a prevalence of essential and non-essential elements in vitamins and minerals, minerals, and botanicals-based dietary supplements, whereas lower concentrations were found in the dietary supplements based on amino acids. All elements were in a concentration below the recommended dietary allowances (RDAs), exception for those with the concentration intentionally higher. Accuracy of results by MIP OES was evaluated by using standard reference materials (SRM) NIST 1572 and NIST 1575a. In addition, results showed no statistical difference by comparison with those by ICP OES. MIP OES proved to be a suitable technique for the determination of metals in dietary supplements, being a feasible alternative for the quality control of these products.

Simultaneous quantitation of 17 female sex hormones in illegal products by validated LC-high resolution MS and LC-tandem MS methods.

The consumption of food and drugs adulterated with female sex hormones can have an extremely adverse effect on human health. Therefore, developing appropriate monitoring methods for the identification of various exogenous female sex hormones is crucial for minimizing and eliminating the related health risks. Herein, 17 female hormones categorized into two groups, estrogen and progestin, were analyzed using reversed phase LC coupled to Orbitrap or triple quadrupole MS. The fragmentation patterns for all compounds were discovered, and fragmented structures were also derived from them through LC-high resolution MS followed by qualitative sample analysis. In addition, quantitative analysis of 67 samples of illicit drugs and dietary supplements was performed using the validated LC-tandem MS method. Female hormone components were detected in two samples of an unauthorized injectable solution and a tablet-type drug. Medroxyprogesterone was detected in the samples in the range of 96.4-206 ng/g. Notably, eight components similar in structure to steroids were simultaneously detected as male sex hormones by confirming their fragmentation ion patterns using LC-high resolution MS. The developed methods thus offer a dependable, and practically applicable approach for the screening and detection of exogenous female sex hormones in real food and drug samples to ensure public health. This article is protected by copyright. All rights reserved.

Green Analytical Method for Simultaneous Determination of Glucosamine and Calcium in Dietary Supplements by Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection.

The need for analytical methods that are fast, affordable, and ecologically friendly is expanding. Because of its low solvent consumption, minimal waste production, and speedy analysis, capillary electrophoresis is considered a "green" choice among analytical separation methods. With these "green" features, we have utilized the capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C4D) to simultaneously determine glucosamine and Ca2+ in dietary supplements. The CE analysis was performed in fused silica capillaries (50 μm inner diameter, 40 cm total length, 30 cm effective length), and the analytical time was around 5 min. After optimization, the CE conditions for selective determination of glucosamine and Ca2+ were obtained, including a 10 mM tris (hydroxymethyl) aminomethane/acetic acid (Tris/Ace) buffer of pH 5.0 as the background electrolyte; separation voltage of 20 kV; and hydrodynamic injection (siphoning) at 25 cm height for 30 s. The method illustrated good linearity over the concentration range of 5.00 to 200 mg/L of for glucosamine (R 2 = 0.9994) and 1.00 to 100 mg/L for Ca2+ (R 2 = 0.9994). Under the optimum conditions, the detection limit of glucosamine was 1.00 mg/L, while that of Ca2+ was 0.05 mg/L. The validated method successfully analyzed glucosamine and Ca2+ in seven dietary supplement samples. The measured concentrations were generally in line with the values of label claims and with cross-checking data from reference methods (HPLC and ICP-OES).

Изучение биологических свойств и антибиотикорезистентности пробиотических бактерий из Кореи и Японии

The scope of the study is to study the biological properties of dietary supplements line: LactoBalance multiprobiotic, Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, isolation and generic identification of probiotic microorganisms from samples, confirmation of their growth properties and study of their antibiotic resistance. Materials and methods. The study confirmed that the number of probiotic microorganisms in the Lactobalance product line corresponds to those declared by the manufacturer. From biologically active food additives, probiotic microorganisms were isolated, identified and classified according to GOST R 56139-2014, MU 2.3.2.2789-10 [6, 7] and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF). Isolation and cultivation of bifidobacteria strains and thermophilic streptococcus were carried out on a nutrient medium for the cultivation and isolation of bifidobacteria (FBSI SSC PMB, Obolensk, Russia), lactobacilli strains – on a nutrient medium MRS (HiMedia Laboratories Pvt. Limited, India). The growth properties of isolated probiotic microorganisms were studied by passaging them on nutrient media and their resistance to the most clinically significant antibiotics (Amoxicillin + clavulanic acid, Cefixime, Ciprofloxacin, Azithromycin, Clarithromycin, Levofloxacin, Oxacillin) and to the antiprotozoal and antimicrobial substance Metronidazole was determined using 2 methods: disco-diffusion method (DDM) and minimum inhibitory concentration (MIC) using strips. The studies used antibiotic discs and MIC strips manufactured by HiMedia Laboratories Pvt. Limited (India), Liofilchem srl. (Italy). Results. From the studied samples of dietary supplements, probiotic bacteria were isolated and identified (11 strains of bifidobacteria, 7 strains of lactobacilli and 1 strain of thermophilic streptococcus, which corresponds to those declared by the manufacturers). The number of living probiotic microorganisms was determined and their growth properties were confirmed. When studying the bacteria included in Lactobalance, almost all isolated strains and, in general, consortia of bacteria had resistance or low natural sensitivity to cefixime and ciprofloxacin, oxacillin. All lactobacilli were naturally resistant to metronidazole. Among bifidobacteria, the B. longum strain was resistant to metronidazole. All bacteria were highly sensitive to levofloxacin, amoxicillin with clavulanic acid, azithromycin and clarithromycin. As part of Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, 84% of the isolated bacteria, as well as the consortium of bacteria, were resistant or had low sensitivity to ciprofloxacin, cefixime, metronidazole and oxacillin. B. bifidum was resistant to azithromycin and clarithromycin. All isolated bacteria showed sensitivity to amoxicillin with clavulanic acid and levofloxacin, but the consortium of bifidobacteria showed high sensitivity only to amoxicillin with clavulanic acid. The decrease in sensitivity to other antibiotics is associated with the synergy of the properties of individual strains. Conclusion. Based on the results of in vitro studies, it can be concluded that the probiotic bacteria included in the Lactobalance dietary supplement line correspond to the declared species and their quantity and retain their growth properties. When taking all dietary supplements in the Lactobalance line while taking antibiotic therapy with cefixime, ciprofloxacin and oxacillin, as well as taking metronidazole, there is a possibility of colonization of the intestinal mucosa with probiotic strains included in their composition. When taking Neobiotic Lactobalance and Neobiotic Lactobalance Baby/Lactobalance Baby, there is a possibility of colonization of the intestinal mucosa with probiotic strains while taking cefixime, metronidazole, ciprofloxacin, oxacillin, azithromycin and clarithromycin. Key words: probiotics, bifidobacteria, lactobacilli, thermophilic streptococcus, natural antibiotic resistance, minimum inhibitory concentration of antimicrobial drugs

Dietary supplements as a source of anthocyanins

Currently, dietary supplements of plant origin based on raw materials containing anthocyanins are widely used. These compounds belong to the class of flavonoids and are glycosides of the flavylic cation. The properties of anthocyanins are associated with their hypolipidemic, hypoglycemic and antioxidant activity. The total content of anthocyanins should be taken into account when developing recipes for dietary supplements. The qualitative composition of individual anthocyanins is an important criterion for the authenticity of this type of product. The purpose of the research was to study anthocyanin content and composition in some dietary supplements that have undergone the procedure of state registration. Material and methods. 34 samples of dietary supplements based on raw materials containing anthocyanins were analyzed. Determination of the total content of anthocyanin pigments was carried out by differential spectrophotometry. The qualitative composition of individual anthocyanins (anthocyanin profile) was determined by reverse-phase HPLC with photometric detection at 510 nm. The peaks of individual compounds were identified by comparing the chromatogram of the sample with experimental and literary data on the order of elution of the most common anthocyanins. Results. The total content of anthocyanins in the analyzed samples varied in a wide range - from 0.013 to 20.8 mg per serving. The study of the anthocyanin profile showed compliance with the declared composition except two samples: in the first, acai extract was used instead of blueberry extract, in the second, black currant extract instead of acai extract. Despite the presence of anthocyanins in the vast majority of dietary supplements studied, only 33% of them can be positioned as sources of anthocyanins. Conclusion. The use of purified extracts with a high content of anthocyanins could solve the problem of low concentration of bioactive compounds in dietary supplements. The conducted research confirms the need for careful monitoring of the content of anthocyanin pigments in products.

Xác định đồng thời hàm lượng một số vitamin nhóm B bằng phương pháp điện di mao quản sử dụng detector độ dẫn không tiếp xúc (CE-C4D)

The simultaneous determination of vitamin B1, vitamin B5, and vitamin B9 in dietary supplements was investigated by using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D). Optimal conditions included: fused silica capillary inner diameter (ID) 50 µm and total length of 50 cm (effective length of 30 cm); electrolyte solution of 12 mM Arginine/Acetic acid/ 10% Acetonitrile; pH = 7.5; hydrodynamic injection at height of 15 cm in 30 s; separation voltage of 17 kV. Calibration curves were constructed over the range from 1.0 to 100 ppm (vitamin B1) and 2.0 ppm to 100 ppm (vitamin B5, vitamin B9) giving good linear correlation coefficients (R2 > 0.999). The limits of detection (LOD) for vitamin B1, B5 and B9 were 0.3, 0.5 and 0.6 ppm, respectively. The recoveries were ranging from 94.9% to 105.0%. The developed method was applied to simultaneously determine vitamin B1, B5 and B9 in 4 dietary supplement samples. The results of these vitamins in the samples differ from their labels by -11.67% to +12.50%. The CE-C4D results were compared with those obtained by reference UPLC-MS/MS method, showing good agreement between the two methods (relative error < 10.53%).

Determination of Curcuminoids, Piperine, Boswellic Acids and Andrographolides in Food and Dietary Supplements by HPLC.

As use of functional food and herbal combination products is ever increasing, methods for quality control of such preparations are necessary. Moreover, low quality of products can cause either lack of benefit or harm to the consumer. In this work, determination of three curcuminoids, piperine, six boswellic acids and three andrographolides, often used in combination products, was carried out in raw materials and dietary supplements. After extraction optimization using Box-Behnken design, maximum active substance yields were obtained using 81.5% ethanol in hydroethanolic extraction solvent, 30 min sonication time and 60 °C extraction temperature. Afterwards, a high-performance liquid chromatography method was developed and validated, with special attention paid to selectivity, precision and robustness of the method. Lastly, 54 food and dietary supplement samples were analyzed. Most products were bought locally, from credible vendors and they all complied with relevant regulatory requirements. However, products obtained on the Internet contained little to no active substances (24% of samples contained less than 20% declared content), presumably showing no efficacy, or were either found to be likely adulterated or contained very high amounts of active substances, compromising safety in terms of dose-dependent adverse effects (one sample containing andrographolides) and pharmacokinetic interactions (one sample containing piperine). In conclusion, consumers should refrain from purchasing such products from the Internet and obtain them only from verified suppliers such as local pharmacies or health stores. This work demonstrates the first developed method for the analysis of aforementioned combination products, which are on the rise today. The method is simple and robust and can be adapted by most laboratories for routine quality control of the said products. Moreover, the work sheds light on the low quality of several products and signifies the need for increased consumer awareness of dangers of taking such products.