Soft Drink Samples Research Articles

Poly(N-isopropylacrylamide-co-N,N′-methylene bisacrylamide) monolithic column embedded with γ-alumina nanoparticles microextraction coupled with high-performance liquid chromatography for the determination of synthetic food dyes in soft drink samples

The present work proposes a study of the synthesis of poly(N-isopropylacrylamide-co-N,N′-methylene bisacrylamide) monolithic column embedded with γ-alumina nanoparticles and its applications to the extraction of synthetic food dyes in soft drink samples. The monolithic column was synthesized inside fused silica capillaries using thermally initiated free-radical polymerization with N-isopropylacrylamide (NIPAAm) as the monomer, N,N′-methylene bisacrylamide (MBAAm) as the cross-linker, dimethylsulfoxide (DMSO) and dodecanol as the porogen. γ-Alumina nanoparticles were introduced to prevent the swelling of the organic polymer and enhance the loading capacity. In order to obtain optimum experimental conditions, sample pH, sample flow rate, sample volume, eluent flow rate were investigated. Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. When applied to the determination of four synthetic food dyes (Tartrazine, Sunset Yellow, Allura Red, and Azorubine) in soft drink samples, satisfactory recoveries were obtained in the range of 90.4–109.2%.

One-step electrochemical approach for the preparation of graphene wrapped-phosphotungstic acid hybrid and its application for simultaneous determination of sunset yellow and tartrazine

We have demonstrated a one-step and effective electrochemical method to prepare graphene (GN) layer-wrapped phosphotungstic acid (PTA) hybrid on the surface of glassy carbon electrode (GCE) using graphene as an electron transfer mediator. The PTA coupled with graphene provides good selectivity and high sensitivity for the simultaneous determination of two synthetic food colorants, sunset yellow and tartrazine, exhibiting as well-defined oxidation peaks in differential pulse voltammetry with a peak potential separation of ca. 260mV. The detection limit was found to be 0.5μgL−1 for sunset yellow and 30.0μgL−1 for tartrazine. The interference of some common food additives was studied and it was concluded that application of this method for the determination of sunset yellow and tartrazine in several commercial soft drink samples led to satisfactory results. This study provides useful further evidences for the development of portable sensors for food additives.

Development and Validation of a Green High Performance Liquid Chromatographic Method for the Determination of Some Artificial Sweeteners and Caffeine in Soft Drinks

A simple and green high performance liquid chromatographic method was developed to determine the acesulfame K, saccharin, aspartame, and caffeine content in soft drinks without the use of toxic organic solvents. Separation was carried out on a C18 column using ethanol–phosphate buffer as the mobile phase at 0.8 mL/min. Optimum separation was achieved in 15 min. Acesulfame K, saccharin, aspartame, and caffeine were detected at 225, 217, 217, and 280 nm, respectively. The calibration curves were linear (correlation coefficient ≥0.999) in the selected range of each analyte. The limit of detection was 0.024 mg/L for acesulfam K, 0.011 mg/L for saccharin, 0.024 mg/L for caffeine, and 0.014 mg/L for aspartame. The relative standard deviations in inter and intra-laboratory precision studies varied from 0.44% to 1.61%. Recoveries of the analytes from spiked diet cola samples were between 98.40% and 100.25%. The validated method was found to be accurate and precise in the working calibration range. The developed analysis method was applied to 56 soft drink samples and was statistically compared with a conventional method by using test material. In conclusion, the developed HPLC analysis method provided more accurate values than the conventional analysis method.

Comparison of six multiclass classifiers by the use of different classification performance indicators

Classification problems are very important, and generally, the question is which is the best model. Several classification performance indicators including the classification accuracy value (ACC), Cohen's kappa (KAPPA), or the area under the ROC curve (AUC) are used to answer this question. There are non‐parametric comparative methods such as the sum of ranking differences method. The objective of this work was to find the best classification method to classify four soft drink samples and four model samples, which differ from each other only in the sweetener composition. Model samples were used to be basic samples for comparison with the commercial soft drinks. Six different classification methods were compared according to their classification performance. A corrected classification accuracy value (corrected ACC) was developed for the purpose and was introduced. This value takes into account the similarities between the classes. The results showed that the ACC value and the KAPPA values give similar results in our case. The best three models according to the ACC, KAPPA, and AUC were “K‐nearest neighbor,” “random forest,” and “discriminant analysis.” However, the corrected ACC value showed a bit different ranking, and the random forest model was neglected from the good models. The confusion matrices of the models confirmed the ranking according to the corrected ACC value. The results showed that the best classification model was the K‐nearest neighbor for the available samples, and the corrected ACC value is a useful classification performance indicator. Copyright © 2012 John Wiley & Sons, Ltd.

Assay of Tartrazine Dye Concentration in Foodstuff Products by New Potentiometric Carbon Paste Electrode

Tartrazine (E102) dye (Na3TZ) in real samples was determined by a new modified carbon paste electrode based on Tartrazine-Cetryltrimethyl ammoniumbromide (TZ-CTAB) as a chemical modifier. The construction, performance, and applications of E102 dye carbon paste electrode are described. The best performance was exhibited by the electrode having the paste containing 3.0 wt% ionexchangers (TZ-CTAB), 46.2 wt% graphite and 50.8 wt% dioctyl phthalate (DOP). The modified electrode showed a near-Nernstian slope of 18�1±0�5 mV over the concentration range of 8�3× 10−7−1�0×10−2 M with the limit of detection 4�7×10−7 over the pH range 3.2–7.6. The proposed sensor revealed good selectivities over a wide variety of anions and sugars. The developed electrode was applied to the potentiometric determination of tartrazine ion in its aqueous solution and in different kinds of foodstuffs: Solid jelly (strawberry and custard) powder samples and soft drink (orange) samples with satisfactory results. The proposed potentiometric method offers the advantages of simplicity, accuracy, automation feasibility and applicability to turbid and colored sample solutions.

Study on the occurrence of pesticide residues in fruit-based soft drinks from the EU market and morocco using liquid chromatography–mass spectrometry

While a plethora of regulation is available for pesticide control in fruits, vegetables, baby food or drinking water, scarce attention is still devoted to derivate products, which may contain these commodities as an ingredient, such as fruit-based soft drinks. A recent study (García-Reyes, Gilbert-López, Molina-Díaz, & Fernández-Alba, 2008) revealed the presence of relatively large concentrations of pesticides on a study carried out on 100 fruit-based soft drink samples, purchased from 15 different countries. In this work, a follow-up study on the occurrence of multiclass pesticides in fruit-based soft drinks is presented. This new monitoring program was undertaken on fruit-based soft drink samples from different European Union countries and also from Morocco. To accomplish the monitoring program, a liquid chromatography electrospray time-of-flight mass spectrometry method was used for the determination of 30 representative multiclass pesticides in fruit-based soft drinks, including the most frequently detected post-harvest fungicides. Sample treatment was based on solid-phase extraction (SPE) using polymer-based SPE cartridges. The identification and confirmation of the compounds was based on retention time and accurate mass measurements of the protonated molecules ([M + H]+) and their main fragment ions. Isotopic profile was also used for the confirmation of compounds containing halogen atoms in their structure (e.g. imazalil, prochloraz). The proposed method was successfully applied to 94 fruit-based soft drink samples obtained during 2009–2010 from 10 European countries and from Morocco. Residues of up to eleven different pesticides were detected. As in the previous studies, soft drink samples addressed pesticide residues in the μg L−1 concentration level (from 0.1 to 36.1 μg L−1), particularly from post-harvest fungicides that are usually present in the peel of citrus fruits (carbendazim, imazalil, imazalil metabolite, prochloraz, thiabendazole and buprofezin). Therefore, the exposure to these chemicals through these beverages still remains (90% of positive samples in the present study) and unambiguous specific regulations are still to be established.

A Single Platinum Microelectrode for Identifying Soft Drink Samples

Cyclic voltammograms recorded with a single platinum microelectrode were used along with a non-supervised pattern recognition, namely, Principal Component Analysis, to conduct a qualitative analysis of sixteen different brands of carbonated soft drinks (Kuat, Soda Antarctica, H2OH!, Sprite 2.0, Guarana Antarctica, Guarana Antarctica Zero, Coca-Cola, Coca-Cola Zero, Coca-Cola Plus, Pepsi, Pepsi Light, Pepsi Twist, Pepsi Twist Light, Pepsi Twist 3, Schin Cola, and Classic Dillar’s). In this analysis, soft drink samples were not subjected to pre-treatment. Good differentiation among all the analysed soft drinks was achieved using the voltammetric data. An analysis of the loading plots shows that the potentials of −0.65 V, −0.4 V, 0.4 V, and 0.750 V facilitated the discrimination process. The electrochemical processes related to this potential are the reduction of hydrogen ions and inhibition of the platinum oxidation by the caffeine adsorption on the electrode surface. Additionally, the single platinum microelectrode was useful for the quality control of the soft drink samples, as it helped to identify the time at which the beverage was opened.

An Ozone Reactor Design with Various Electrod Configurations

Environmental pollution is increasing, including water pollution due to industrial and household. To overcome this, there are three main concerns, namely the policy and environmental management, environmental awareness of society, and utilization of appropriate technologies to overcome pollution. This study is an attempt to overcome the problems of environmental pollution by designing, creating, and applying appropriate technology to make Ozone reactor with high-voltage corona discharge plasma technology. There are some methods of electrod configuration, namely wire-cylinder, spiral-cylinder, wire-cylinder with Dielectric Barrier Discharge (DBD), and spiral-cylinder with DBD. Corona discharge occurs between high-voltage electrod of each configuration ionize Oxygen flowed in the reactor, thus generating plasma and forming Ozone. The test of four Ozone reactors have been done by wastewater treatment in the form of soft drink samples, obtain the fading colors of wastewater, which is increasingly fade over many cycles of waste treatment process conducted in Ozon reactor. Based on comparison of four of Ozone reactor, it is obtained waste water treatment more maximal on reactor Ozone configuration of spiral-cylinder electrod with DBD. Keywords: Ozone reactor, electrods configuration, corona discharge, wastewater DOI: http://dx.doi.org/10.11591/ijece.v1i2.79

Sequential Injection Chromatography as Alternative Procedure for the Determination of Some Food Preservatives

Sequential injection chromatography for the determination of benzoic acid (BA), sorbic acid (SOA), and salicylic acid (SA) has been investigated. Separation was performed on a monolithic C-18, (5 × 4.6 mm) column which is normally used as a guard column, with 1% acetonitrile: ammonium acetate buffer pH 4.5 as a mobile phase at a flow rate of 1.20 mL/min at ambient temperature and with the UV detection at 235 nm. Under the conditions, separation of the three compounds was achieved within less than 3 min. Linear calibrations were found to be 1–100 mg/L for the three: BA, SOA, and SA with detection limits of 1.9, 0.7, and 0.3 mg/L. The developed procedure was demonstrated to be an effective alternative fast and simple method for the analysis of food, fruit juice, syrup, and soft drink samples.

Juice from king palm (Archontophoenix alexandrae) leaf sheathes: chemical characterisation and use in soft drink formulation

SummaryThe heart of palm is a food extracted from several species of palm trees. Only 10–20% of the raw material is transformed into canned hearts of palm, therefore this agro‐industry generates a large quantity of solid residue. The aim of this work was to extract and characterise a juice produced from this solid residue. This extract is compared with the traditional fruit juices (orange and pineapple juices), obtaining higher contents of minerals, such as magnesium (22.80 mg/100 g) and potassium (276.90 mg/100 g), phenolic compounds (gallic, 3,4‐dihydroxybenzoic, chlorogenic, syringic and caffeic acids) and high free radical scavenging capacity (expressed as 2,2‐diphenyl‐1‐picrylhydrazyl), which suggest high antioxidant activity. Additionally, a new soft drink was formulated using this king palm juice as its main ingredient. The soft drink samples formulated with this juice had high sensory acceptability and high intention of consumption, which suggests an important and low‐cost application for this industrial residue.

Determination of Artificial Sweeteners in Beverages and Special Nutritional Products Using High Performance Liquid Chromatography

This paper presents two high performance liquid chromatographic (HPLC) methods used for the separation and determination of artificial sweeteners aspartame, acesulphame K, sodium saccharin, and sodium cyclamate in beverages and special nutritional products (special food intended for specific population groups). All four compounds are soluble in aqueous solutions and can easily be separated and determined by HPLC with a diode array detector (DAD). The first method involved separation of aspartame, acesulphame K, and sodium saccharin on a C18 column with an isocratic elution of phosphate buffer and acetonitrile as mobile phase. The second method was used to separate sodium cyclamate on a C18 column with methanol and water as mobile phase. Under optimum conditions, both methods showed good analytical performance, such as linearity, precision, and recovery. The methods were successfully applied for the analysis of real samples of soft drinks and special nutritional products.

Application of cetyltrimethylammonium bromide – graphene modified electrode for sensitive determination of caffeine

An electrochemical sensor based on a cationic surfactant cetyltrimethylammonium bromide (CTAB) – dispersed graphene (Gr) system for sensitive detection of caffeine is presented. The electrochemical behavior of caffeine on the modified glassy carbon electrode was investigated by cyclic voltammetry and differential pulse voltammetry. The results showed that the modified electrode exhibited good electrocatalytic activity to the oxidation of caffeine. Under the optimized experimental conditions, caffeine was detected in the concentration range from 0.3 to 100 µmol L–1 with a detection limit of 91 nmol L–1 at a signal-to-noise ratio = 3. The biosensor exhibited some advantages over other electrochemical sensors, such as long-term stability, satisfactory recovery (98.1%−102.3%), and good reproducibility (RSD = 5.1%). The practical application of the developed method was verified in soft-drink sample analysis.

Highly sensitive and accurate screening of 40 dyes in soft drinks by liquid chromatography–electrospray tandem mass spectrometry

A method combining solid phase extraction with high performance liquid chromatography–electrospray ionization tandem mass spectrometry was developed for the highly sensitive and accurate screening of 40 dyes, most of which are banned in foods. Electrospray ionization tandem mass spectrometry was used to identify and quantify a large number of dyes for the first time, and demonstrated greater accuracy and sensitivity than the conventional liquid chromatography–ultraviolet/visible methods. The limits of detection at a signal-to-noise ratio of 3 for the dyes are 0.0001–0.01 mg/L except for Tartrazine, Amaranth, New Red and Ponceau 4R, with detection limits of 0.5, 0.25, 0.125 and 0.125 mg/L, respectively. When this method was applied to screening of dyes in soft drinks, the recoveries ranged from 91.1 to 105%. This method has been successfully applied to screening of illegal dyes in commercial soft drink samples, and it is valuable to ensure the safety of food.

Hollow-fiber liquid–liquid–solid micro-extraction of lead in soft drinks and determination by graphite furnace atomic absorption spectrometry

A novel hollow-fiber liquid–liquid–solid micro-extraction technique based on simultaneous liquid–liquid micro-extraction and solid phase micro-extraction using a polypropylene microporous membrane has been developed. The applicability of the proposed procedure was evaluated by extraction of Pb(II) from aqueous solutions and soft drinks. The parameters affecting the extraction efficiency were optimized using multivariate methodology, and the analytical features were established. Under optimized conditions, Pb(II) was concentrated for 20 min on three microporous membrane hollow fibers of 6 mm of length each, placed into 20 mL of sample containing 60 μL of toluene and ammonium O,O-diethyl dithiophosphate. The fibers were introduced directly into the graphite furnace as a solid sample, and the analyte was thermally desorbed from the fiber and atomized using ruthenium as a permanent modifier. A detection limit of 7 ng L −1 Pb was obtained for soft drink samples and good repeatability was found for all samples. The enrichment factor varied between 22 and 66, depending if only one or all three hollow fibers were used for the determination of lead. The results suggest that the proposed procedure represents a simple and low-cost micro-extraction alternative rendering adequate limits of quantification for the determination of Pb(II) in soft drink samples.

Determination of THMs in soft drink by solid-phase microextraction and gas chromatography

In this study, a simple and fast method was developed for the analysis of trihalomethanes (THMs) in soft drink samples using headspace solid-phase microextraction coupled with gas chromatography (HS-SPME–GC). The influence of factors, such as, extraction temperature, extraction time, addition of sodium chloride and agitation speed on extraction yield was studied through an univariate experimental design strategy. Satisfactory recoveries (⩾90%) and precision, calculated as the relative standard deviations (RSD⩽11%), were obtained. The limit of detection (LOD) between 0.22 and 0.46μgL−1 was achieved for THMs along with a wide linear range of concentrations. The applicability of the proposed method was demonstrated by analysing 74 real soft-drink samples. Since no matrix effects were observed, quantification could readily be carried out by external calibration with deionized water standards.

Multiclass determination of pesticides and priority organic pollutants in fruit-based soft drinks by headspace solid-phase microextraction/gas chromatography tandem mass spectrometry

In this work, a simple, environmentally friendly, rapid and reliable GC-MS/MS method has been developed for the determination of 45 organic contaminants (32 pesticides and 13 PAHs) in fruit-based soft-drinks. The proposed method consists of a solventless sample treatment procedure based on headspace solid-phase microextraction using a fiber of polyacrylate (PA), followed by identification and quantitation of the target pesticides by gas chromatography-tandem mass spectrometry (GC-MS/MS) using a triple quadrupole analyzer in the multiple reaction monitoring (MRM) acquisition mode. Several parameters of the automated extraction were studied including the incubation time, temperature, sample volume and type of SPME fibers. The identification and confirmation of the compounds were based on the retention time matching along with the presence (and relative abundances ratio) of three characteristic MRM transitions (except for PAHs, in which two transitions were used). Fruit-based soft drinks spiked at 100 ng L−1 yielded average recoveries in the range 75–113% with RSD (%) below 15% (n = 8). The obtained limits of detection varied in the range 0.1–180 ng L−1. The proposed method was successfully applied to the analysis of 26 market purchased fruit-based soft drink samples collected mainly in Spain, but also in some other countries, showing its potential applicability and revealing the presence of some of the target species in the ng L−1 range (from 1.5 to 320.8 ng L−1).

Simultaneous determination of diethylene glycol, diethylene glycol monoethyl ether, coumarin and caffeine in food items by gas chromatography

A simple gas chromatography–flame ionisation method was initially developed for the simultaneous determination of the prohibited flavours, namely diethylene glycol (DEG), diethylene glycol monoethyl ether (DEGME) and coumarin in food samples. The analytes were extracted using methanol, and was sonicated for 10min. The extracts were filtered and directly injected into the GC unit that was fitted with a capillary ATTM-AQUAWAX column. Caffeine, which was found in some of the soft drink samples were also successfully separated. Excellent separation of these flavours and caffeine was achieved in about 23min. Limit of detection, linear range, and reproducibility of the retention time were evaluated. Average recoveries in the ranges of 93.44–97.54% (RSD, 2.68%) for DEGME, 92.99–101.45% (RSD, 2.99%) for DEG, 90.64–100.00% (RSD, 1.99%) for coumarin and 94.62–97.50% (RSD, 2.54%) for caffeine were obtained. None of the food items analysed was found to contain coumarin, DEG or DEGME. However, of the 35 soft drinks and fruit juices that were analysed, eleven samples were found to contain caffeine, but only one exceeded the legal limit.

Determination of preservatives by integrative coupling method of headspace liquid-phase microextraction and capillary zone electrophoresis

An integrative coupling method of headspace liquid-phase microextraction (HS-LPME) and capillary zone electrophoresis (CZE) was proposed in this paper. In the method, a separation capillary was used to create a microextraction droplet of the running buffer solution of CZE, hold the droplet at the capillary inlet, extract analytes of sample solutions in the headspace of a sample vial, inject concentrated analytes into the capillary and separate the analytes by CZE. The proposed method was applied to determine the preservatives of benzoic acid and sorbic acid in soy sauce and soft drink samples, in which the running buffer solution of 50 mmol/L tetraborate (pH 9.2) was directly used to form the acceptor droplet at the capillary inlet by pressure, and the preservatives in a 6-mL sample solution containing 0.25 g/mL NaCl were extracted at 90 °C for 30 min in the headspace of a 14-mL sample vial. Then the concentrated preservatives were injected into the capillary at 10 cm height difference for 20 s and separated by CZE. The enrichment factors of benzoic acid and sorbic acid achieved 266 and 404, and the limits of detection (LODs) were 0.03 and 0.01 μg/mL (S/N = 3), respectively. The recoveries were in the range of 88.7–105%. The integrative coupling method of HS-LPME and CZE was simple, convenient, reliable and suitable for concentrating volatile and semi-volatile organic acids and eliminating matrix interferences of real samples.

Simultaneous determination of aspartame, cyclamate, saccharin and acesulfame-K in soft drinks and tabletop sweetener formulations by capillary electrophoresis with capacitively coupled contactless conductivity detection

Capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C 4D) was used for simple, rapid, and simultaneous determination of aspartame, cyclamate, saccharin and acesulfame-K in commercial samples of soft drinks and tabletop sweetener formulations. A buffer solution containing 100 mmol L −1 tris(hydroxymethyl)aminomethane (TRIS) and 10 mmol L −1 histidine (His) was used as background electrolyte (BGE). A complete separation of the analytes could be attained in less than 6 min. The limits of detection (LOD) and quantification (LOQ) were considered better than those usually obtained by CE with photometric detection. Recoveries ranging from 94% to 108% were obtained for samples spiked with standard solutions of the sweeteners. The relative standard deviation (RSD) for the analysis of the samples with the CE-C 4D method varied in the range of 1.5%–6.5%.

Sources of low concentrations of bisphenol A in canned beverage products.

Although migration from can coatings is likely the source of bisphenol A (BPA) for the canned soft drink products with relatively high BPA concentrations, questions have been raised concerning the exact sources of BPA for those canned soft drink products with low BPA concentrations. Information is also needed for BPA concentrations in canned beer products to conduct proper exposure assessment for BPA under the Government of Canada's Chemicals Management Plan. In this work, 22 soft drink samples and 16 beer samples in both cans and plastic and/or glass bottles were analyzed for BPA. BPA was not detected in any of the soft drink samples in either plastic or glass bottles except for one product with a BPA concentration (0.018 microg/liter) close to the limit of quantification (0.015 microg/liter). BPA was detected in all of the corresponding soft drink products in cans, indicating that migration from can coatings is the likely source for BPA in canned products. Because considerable interference with ions m/z 213 and m/z 228 from sample matrices was observed for all beer samples, BPA concentrations in beer samples were measured using the ion m/z 270 instead. BPA was detected in only one of the seven beer products in glass bottles (0.054 microg/liter) but was detected in all corresponding beer samples in cans at low concentrations ranging from 0.081 to 0.54 microg/liter, indicating that migration from can coatings is likely the source of BPA in canned beer products.