Acid In Beverages Research Articles

Cuprospinel decorated biopolymer functionalized CNFs based electrocatalytic platform integrated with grid search optimized neural network for detection of vital amino acid in beverages

An electrocatalytic platform based on a novel nanocomposite integrated with a grid search-optimized neural network (GSNN) was proposed for intelligent sensing of tryptophan. The cuprospinel-decorated chitosan-functionalized carbon nanofibers (CuFe2O4/Chit-CNFs) fabricated on a disposable electrode revealed exceptional electrocatalytic activity with a low detection limit (2 nM) and good sensitivity (79.18 μAμM−1 cm−2) over a broad linear range (0.05–152.55 μM). Cyclic voltammetry and differential pulse voltammetry were employed, and the sensing mechanism of tryptophan entails its electrocatalytic oxidation, where the synergistic impact of CuFe2O4 and Chit-CNFs boosts electrochemical response owing to their high surface area and conductivity. GSNN-based intelligent sensing returned a root mean square error (RMSE) of 2.76 and a mean absolute error (MAE) of 1.12. Moreover, the sensor's performance was tested on samples from apple juice, tomato juice, pineapple juice, and milk for assessing practicality, demonstrating recovery between 96.93 and 101.06 % and maximum relative standard deviation of 2.63 %. The proposed sensor showcased excellent selectivity, repeatability, reproducibility, and stability.

Evaluation of the effects of storage time and temperature on the beverages

Beverages are an important part of the food sector their storage is also one of the most critical issues. This study investigated the effects of different storage temperatures and times on physicochemical properties, flavonoid and organic acid contents of soda, sherbet and ice tea produced by adding sour grape concentrate. Changes in the flavan-3-ol content of ice tea were also measured during the storage period. The beverages were stored in three different conditions, cold storage (~4°C), room temperature (~24°C) and controlled storage (20±1°C), for six months and analyzed every two months. Storage temperatures and time affected the total soluble solids and acidities of the beverages (p≤0.05). Tartaric acid decreased during storage, especially during the first two months in sherbets. Ice tea and soda drinks were found more stable than sherbets. The malic acid was found the major organic acid in beverages. Flavonoid content in ice tea was higher than others. The flavonoid concentrations of ice tea stored at 20 and 24°C and of sherbet at 4°C were statistically significant as a function of storage time while these values were not significant for ice tea stored at 4°C and of sherbet at 20 and 24°C (p≤0.05). Concentrations of flavan-3-ols varied with storage conditions. The levels of epicatechin, epigallocatechin and epigallocatechin gallate in ice tea samples decreased between an average of 43.72 and 71.15% at the end of six months of storage. Principal component analysis separated two months storage from other storage periods and perfectly discriminated the studied flavan-3-ols except catechin. Soluble solid and brix-acid ratio also dissociated similarly to flavan-3-ols.

A novel fluorescence sensor based on Al3+-mediated aggregation of gold nanoclusters for determination of citric acid in beverages.

This paper revealed a new strategy for citric acid (CA) detection using aggregation-induced emission (AIE)-based fluorescent gold nanoclusters (AuNCs). AuNCs was synthesized using glutathione (GSH) as the template and reducing agent and used as the fluorescent probe to detect CA under aluminum ion (Al3+) mediation. The fluorescence intensity of AuNCs increased about 4 times with the addition of Al3+, but the enhanced fluorescence was quenched after the addition of CA. Based on this fluorescence phenomenon, an "on-off" fluorescence strategy was designed for the sensitive determination of CA and a linear detection range for CA was achieved within 0-80.0 μM. In addition, the developed probe exhibited high selectivity and accuracy for determination of CA. The mechanism of fluorescence enhancement and quenching of AuNCs was explored in detail. The established probe was used successfully for CA detection in beverages. The spiked recoveries from 97.50% to 103.67% were gratifying, which indicated the probe had potential prospects for detecting CA in food.

Sensitive method for determination of benzoic acid in beverages and food samples using air–assisted hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction

A simple, reliable and rapid air–assisted hydrophobic deep eutectic solvent-based dispersive liquid–liquid microextraction (AA-HDES-DLLME) was developed for analysis of benzoic acid in various beverages and food samples. The final determination stage was performed via UV–visible spectrophotometry. The key parameters (extraction time, HDES type and volume, dispersant volume, pH and sample volume) of the AA-HDES-DLLME method were optimized in detailed using Box–Behnken design. Analysis of variance was used for statistical analysis. Under the optimized conditions, limit of detection (12.1 μg L−1), limit of quantification (40 μg L−1), linearity range (40–1000 μg L−1), and preconcentration factor (140) were determined. While the accuracy of the AA-HDES-DLLME method was investigated with the standard addition approach, its precision was investigated with intraday/interday studies. The method proved to be effective for routine analytical practice for a wide variety of samples. The novelty of the AA-HDES-DLLME method is that it enables the extraction of benzoic acid without the need for heating or centrifugation steps. In this way, the AA-HDES-DLLME method enabled selective extraction of benzoic acid in a shorter time and using less energy compared to similar studies.

HPLC Method for the Determination of Benzoic acid in samples of commercial children’s food in the Markets of Aden -Yemen

The objective of this study was to determine the quantities of benzoic acid in some local and imported food products for the distributed children in Aden, Yemen. Samples of different food products for children (32) using HPLC method, were collected in August 2022, from different supermarkets in Aden, Yemen. Chromatographic separation was achieved using a C-18 column (EXCGL 120 ODS-A) and acetate buffer pH=4.4 - methanol (65:35) as mobile phase, 1 ml/min flow rate and UV detection at 233 nm. The results show that quantities of benzoic acid in studied samples varies greatly starting from 1.778 ppm to 849.295ppm, All samples of group II beverages and Juices samples and group III jam samples were under the study contain concentrations of benzoic acid within the limits allowed by standards of Yemeni and World Health Organization and the estimated maximum allowable benzoic acid in beverages, Juices and jam to 1000 ppm. All samples of the groups I and V cakes and food for children mainly manufacturers of grain, The samples that were under the study contain concentrations of benzoic acid and it is difficult to compare the amount of benzoic acid in samples of two groups with international standards, regional and local non-existence. All samples of the group IV dry milk and cheese samples under study contain concentrations of benzoic acid within the limits allowed according to the standard specifications of Yemen and specifications of the World Health Organization (WHO), which determined the maximum allowable of benzoic acid in dry milk at 50 ppm and the maximum allowed for benzoic acid in the cheese is 2000 ppm, except for sample No. 28 contains a concentration is higher than the allowable limit.

Exploring the potential of cellulose autofluorescence for optical detection of tannin in red wines

The growing demand for opto-electronic devices within an automated landscape has opened up new opportunities for harnessing sustainable cellulose materials for sensors technology. Cellulose, a versatile material, enables its combination with other materials, but in most of these applications, cellulose is typically employed as support or substrate, while its inherent autofluorescence remains largely underexplored for sensors. In light of this context, this study delves into the autofluorescence characteristics of pristine cellulose nanocrystals extracted from wood via enzymatic route for optical sensors tailored to detect tannins. By fine-tuning the experimental setup, photoluminescence (PL) emission bands were scrutinized across three distinct spectral regions, namely 300–400 nm, 400–500 nm and 550–700 nm. The proposed mechanism reveals the occurrence of dynamic fluorescence quenching, which enabled the selective monitoring of tannins in red wines across a dynamic range spanning from 10 to 1060 μg mL−1. This sensing platform provided a limit of detection (LoD) of 6.1 μg mL−1. Notably, the sensing platform's efficacy was validated with remarkable recovery rates of 99.7 % and 95.3 % when subjected to testing with cabernet sauvignon and tannat wines. These findings emphasize the sensing platform's potential for monitoring tannic acids in beverages and food products.

A fluorescent dual-emitting platform for fluorescent “turn-on” ratiometric detection of ascorbic acid in beverages utilizing luminol-embedded iron-based metal–organic frameworks

A fluorescent dual-emitting platform for fluorescent “turn-on” ratiometric detection of ascorbic acid in beverages was developed utilizing luminol-embedded iron-based metal–organic frameworks (luminol@Fe-DOBDC MOFs). Luminol@Fe-DOBDC MOFs with fluorescent emissions at 430 nm and 540 nm under excitation wavelength of 365 nm were applied to detect ascorbic acid on the basis of ascorbic acid triggering the reduction of Fe3+ into Fe2+. In the presence of ascorbic acid, fluorescent intensity at 540 nm was increased significantly while fluorescent intensity at 430 nm was changed slightly. Two emission peaks separated by 110 nm can eliminate environmental interferences by built-in self-calibration of ratiometric signal, enhancing the sensitivity and accuracy. The increasing ratiometric fluorescent intensity (I540 nm/I430 nm) has linear relationship with the concentration of ascorbic acid from 0.2 to 30 μM with limit of detection of 70 nM. It is an efficient, sensitive and accurate platform to detect ascorbic acid in commercial beverages using transition-metal-based MOFs.

Advanced electrochemical platform for simple and rapid quantification of tannic acid in beverages using batch injection analysis with amperometric detection

In this work, an advanced electrochemical platform was developed for the simple, rapid and sensitive determination of the polyphenolic compound tannic acid in various beverages using the combination of batch injection analysis with amperometric detection on a screen-printed carbon electrode. Several experimental parameters (pH of supporting electrolyte, detection potential, dispensing rate, injected volume, stirring) were consistently evaluated. The most favorable analytical performance in terms of sensitivity, selectivity, repeatability and sampling frequency was obtained in Britton-Robinson buffer pH 5.0 at a detection potential of +0.6 V vs. Ag/AgCl, a dispensing rate of 204 µL/s and an injected volume of 80 µL under stirring condition (1500 r.p.m.). The presented platform has advantages for routine analysis including portable and small-scale experimental setup, low sample consumption (∼100 µL), simple sample preparation (dilution in supporting electrolyte), high sampling frequency (180 injections per hour), low limit of detection (80 nM) and suitable precision (RSD = 4.2% for 10 μM tannic acid, n = 20). The applicability of the method was verified by analyzing several beverage samples (tea, wine) in spike-recovery assay with the recovery values for tannic acid ranging from 94 to 101 %.

Probiotic Whey-Based Beverages from Cow, Sheep and Goat Milk: Antioxidant Activity, Culture Viability, Amino Acid Contents.

Recently, the demand for goat and sheep cheese has increased mainly because of its nutritional and health benefits. As a result, an enormous amount of whey from various animal species is produced as a waste/by-product. The production of functional probiotic fermented beverages from different types of whey protein concentrates (WPC) could be a good way to valorize whey. Meanwhile, reduced environmental pollution and economic sustainability will be provided. In this study, probiotic beverages enriched with 1% kiwi powder were produced from goat, sheep, and cow WPC (15%). Moreover, Streptococcus salivarius subsp. thermophilus and the probiotic bacteria Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis were used for fermentation. The results showed that WPC significantly increased the protein content and acidity of beverages (p < 0.05). Production with WPC also improved the viability of probiotic bacteria and S. thermophilus, total phenolic compound (TPC), and antioxidant activity of beverages. The highest viability of probiotic bacteria (9.67 log CFU/mL for Bb-12 and, 9.35 log CFU/mL for L. acidophilus) was found in beverages produced from goat WPC. In addition, WPC increased the free amino acid content of beverages, and the highest essential amino acids and branched-chain amino acids were found in beverages produced from goat WPC as 146.19 mg/100 g and 70.31 mg/100 g, respectively (p < 0.05). Consequently, while production with goat, cow, and sheep WPC improved quality compared to the control, beverages produced from goat WPC excelled. The production of a functional probiotic beverage with goat WPC is promising for dairy technology.

Straightforward smartphone assay for quantifying tannic acid in beverages based on colour change of Eu3+/polyethyleneimine complex

Tannic acid (TA)—a natural product—is a polyphenol derivative that occurs in certain kinds of beverages. A large amount of TA could give rise to an unpleasant flavour and could negatively affect the human body by causing stomach irritation, abdominal pain, nausea, vomiting, and even death. Thus, the need exists for a simple TA detection procedure that meets specific criteria such as on-site analysis, portability, and affordability. Herein, we present a new TA assay, which is based on the fluorescent quenching effect of an efficient fluorophore, and which comprises a smartphone-integrated homemade reader system. The fluorescent polyethyleneimine-derivatised polymer (FP), a strong emitter at 510 nm, was synthesised with the aid of a facile sonication method. In the presence of Eu3+ ions, TA quenches the fluorescence of the FP via electrostatic interaction. A smartphone was used to capture an image of the FP undergoing fluorescence for conversion to RGB values. The blue channel was chosen for further analysis because it offered the highest R2-value compared to the red and green channels. We verified these results using a commercial spectrofluorometer and calculated the limit of detection of this assay as 87 nM and 20 nM for the homemade reader and spectrofluorometer, respectively. The detection range for TA with the proposed assay is 0.16–66.66 μM. The application of the proposed method to real beverage samples for TA detection demonstrates its analytical applicability.

Development of a paper-based chromogenic strip and electrochemical sensor for the detection of tannic acid in beverages

The nutritive and immunogenic potential of fresh and processed food commodities is largely dependent on the antioxidant capacity and total polyphenolic content. Polyphenols plays a major role in maintaining cellular homeostasis, activation of signaling pathways to initiate immune responses and in the prevention of cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases. Several chromatographic and spectrophotometric methods are used for the identification and quantification of phenolic compounds present in food products and beverages. Here, an electrochemical sensor and a point-of-test paper-based chromogenic strip for the detection of tannic acid in beverages and food products has been developed. The electrochemical sensor showed linear voltametric correlation with a sensitivity of 7.97 × 10−7 A/mM.mm2, whereas, the paper-based chromogenic strip has a detection limit of 0.024 mM. The developed strip and electrochemical sensor have potential to be employed by regulatory agencies and industries for on-site analysis of polyphenolic content in beverages and food products to ensure food safety and quality assessment.

Concise analysis of γ-hydroxybutyric acid in beverages and urine by capillary electrophoresis with capacitively coupled contactless conductivity detection using 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid as background electrolyte

γ-Hydroxybutyric acid (GHB), a neurotransmitter or neuromodulator in the human central nervous system, is often abused in drug-facilitated sexual assaults due to its euphoric and sedative effects. While the analysis of GHB has received continuous attention, its inherent characteristics pose challenges. In the current study, capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D) was built, and Good's buffers were evaluated as the background electrolytes for CE separation and C4D detection. On this basis, a simple and efficient CE-C4D method was developed for GHB analysis. Through theoretical discussion and experimental optimization, the separation of GHB and related positional isomers α-hydroxybutyric acid (AHB) and β-hydroxybutyric acid (BHB) was achieved within 4 min using 150 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as the running buffer. Under the optimized condition, the relative standard deviations of migration time and peak area were less than 1.1% and 4.5%, indicating good precision. The C4D signal of GHB showed a good linear relationship with GHB concentration in the range of 3-300 µM with a determination coefficient of 0.9997, and the detection limit was calculated to be 0.37 µM based on the signal-to-noise ratio of three. Furthermore, liquid-liquid extraction (LLE) and solid-phase extraction (SPE) were comparatively studied for sample matrix purification. Combined with the optimized SPE procedure, the developed CE-C4D method has been successfully applied for the determination of exogenous GHB in spiked beverages and endogenous GHB in human urine.

Simultaneous determination of four organic acids in beverages by capillary electrophoresis coupled with ultraviolet detector

A simple and rapid capillary electrophoresis method with direct ultraviolet (UV)&amp;nbsp;detection was set up for the determination of four organic acids in beverages. The method&amp;nbsp;included dilution and filtration as simple sample preparation steps. The electrophoretic&amp;nbsp;separation and detection of oxalic, malic, citric and lactic acids in wines and beers were&amp;nbsp;performed in 8 min. For the method validation, linearity, detection and quantification limits,&amp;nbsp;repeatability and recovery in wine and beer matrices were studied. Good linearity was&amp;nbsp;observed from 25 to 500 mg/L for all acids excluding lactic acid, for which it started from&amp;nbsp;50 mg/L. The limits of quantitation of oxalic, malonic and citric acid were set 9.5 to 28.5&amp;nbsp;mg/L. Repeatability of this method was from 3.2 to 7.3%, recoveries ranged from 90.1 to&amp;nbsp;110.1%. The validated method was applied to the analysis of different wines and beers and&amp;nbsp;showed great variability in their composition.

Method for the accurate determination of phytic acid in beverages by liquid chromatography-mass spectrometry after methylation with (trimethylsilyl) diazomethane

Phytic acid (PA) plays different roles in various fields of study, yet current analytical methods for PA detection are still unsatisfactory. A novel method has been presented for the determination of PA in beverages, based on complete methylation in combination with liquid chromatography-mass spectrometry (LC-MS) analysis. By treatment with (trimethylsilyl) diazomethane, all the polybasic acid groups in PA were converted to the corresponding ester, and thus the corresponding derivative was easily analyzed by LC-MS. The addition of ethylenediamine tetraacetic acid (EDTA) to the derivative solution improved the sensitivity and the reproducibility in the PA analysis. Under optimized parameters, the linear range of the PA detection was 0.5–100 μg/L, the limit of detection was 0.075 μg/L, the limit of quantitation was 0.25 μg/L, and the recovery range was 81.3–119.7 %. The PA content was determined for 13 commercially available beverage samples, and experimental results showed that this method provided a practical and reliable method for the detection of PA across diverse beverage matrices.

Benzoic Acid Based Beverages: Health Implications

Soft drinks nowadays are becoming an important part of the modern diet consumed in many communities worldwide and are available in the market virtually in the same form almost anywhere around the globe. Additives such as antioxidants and preservatives are usually added to soft drinks to increase their shelf life. Several acids such as benzoic and ascorbic acid are used in beverages to prevent oxidation and degradation of matrix. Literature documented that combination of these preservatives in soft drinks results in benzene formation. Moreover, benzene has long been reported to inflict many public health problems. This review elucidated different health consequences such as hematological, neurological, reproductive and carcinogenic effects of exposure to benzene. Liver and kidney derangements were also reported from different epidemiological and experimental studies. Therefore, we suggest that combination of ascorbic acid and benzoic acid in beverages should be avoided by small scale and industrial manufactures. A closer monitoring of these preservatives in beverages by regulatory agencies is highly needed.

Heteroditopic chemosensor to detect γ-hydroxybutyric acid (GHB) in soft drinks and alcoholic beverages.

Drug-Facilitated Sexual Assault (DFSA) is a problem of considerable dimensions on a global scale. Among the different compounds used in DFSA assaults, 4-hydroxybutyric acid (GHB) is one of the most elusive due to its physical and biological characteristics. Therefore, the development of real-time detection methods to detect GHB not only in drinks but also in urine is very important for personal and social security. Here, we report two new heteroditopic chemosensors capable of recognizing and detecting GHB in soft drinks, alcoholic beverages and synthetic urine. The compounds have two moieties: a trifluoroacetyl group and a thiourea, which are able to interact respectively with the hydroxyl and the carboxylic groups present in the GHB structure. In addition, the distance between these two groups has been optimized to allow a double interaction which guarantees the recognition even in very competitive media such as beverages or urine samples.

Analysis of citric acid and D-isoascorbic acid in beverages by High performance liquid chromatography

In this study, high performance liquid chromatography (HPLC) was used to analysis the content of citric acid and D-isoascorbic acid in beverages. The samples were separated by C18 chromatography column, 0.1 % phosphoric acid solution was used as the mobile phase with the flow rate of 0.5 mL/min, the column temperature was 35 °C, and the detection wavelength was 210 nm. The results showed that the content of citric acid and D-isoascorbic acid has a good linear correlation (r&gt;0.99) within the range of 50 μg to 200 μg. The selectivity, recovery and precision of citric acid and D-isoascorbic acid were suitable. Meanwhile, this method could be used to detect the content of citric acid and D-isoascorbic acid in beverages.

Ag+–3,3′,5,5′-tetramethylbenzidine as a probe for colorimetric detection of ascorbic acid in beverages

A novel and sensitive method for ascorbic acid (AA) determination utilizing Ag+–3,3′,5,5′-tetramethylbenzidine (TMB) as a colorimetric probe was proposed.

Novel Potentiometric 2,6-Dichlorophenolindo-phenolate (DCPIP) Membrane-Based Sensors: Assessment of Their Input in the Determination of Total Phenolics and Ascorbic Acid in Beverages

In this work, we demonstrated proof-of-concept for the use of ion-selective electrodes (ISEs) as a promising tool for the assessment of total antioxidant capacity (TAC). Novel membrane sensors for 2,6-dichlorophenolindophenolate (DCPIP) ions were prepared and characterized. The sensors membranes were based on the use of either CuII-neocuproin/2,6-dichlorophenolindo-phenolate ([Cu(Neocup)2][DCPIP]2) (sensor I), or methylene blue/2,6-dichlorophenolindophenolate (MB/DCPIP) (sensor II) ion association complexes in a plasticized PVC matrix. The sensors revealed significantly enhanced response towards DCPIP ions over the concentration range 5.13 × 10−5–1.0 × 10−2 and 5.15 × 10−5–1.0 × 10−2 M at pH 7 with detection limits of 6.3 and 9.2 µg/mL with near-Nernstian slope of −56.2 ± 1.7 and −51.6 ± 2 mV/decade for sensors I and II, respectively. The effects of plasticizers and various foreign common ions were also tested. The sensors showed enhanced selectivity towards DCPIP over many other phenolic and inorganic ions. Long life span, high potential stability, high reproducibility, and fast response were also observed. Method validation was also verified by measuring the detection limit, linearity range, accuracy, precision, repeatability and between-day-variability. The sensors were introduced for direct determination of TAC in fresh and canned juice samples collected from local markets. The obtained results agreed fairly well with the data obtained by the standard method.

A simple and highly-available microextraction of benzoic and sorbic acids in beverages and soy sauce samples for high performance liquid chromatography with ultraviolet detection

A simple and highly-available air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification (AA-DLLME-OPS) was developed as new approach for pretreatment of complex sample matrix. Menthol was investigated as novel extractant for the AA-DLLME-OPS. In this procedure, a cloudy solution of fine molten menthol droplets is formed when a mixture of molten menthol and aqueous sample is rapidly aspirated into a dispenser and injected into an extraction vial. In the AA-DLLME-OPS, air bubbles promote molten menthol dispersion into aqueous sample phase. Finally, the obtained mixture is cooled and menthol phase is solidified because of the low melting point, which facilitates collection for analysis. To demonstrate the efficiency of the suggested approach, the AA-DLLME-OPS procedure was applied for the HPLC-UV determination of benzoic and sorbic acids as proof-of-concept analytes in beverages and soy sauce samples. The procedure developed provides microextraction of benzoic and sorbic acids from samples with recovery from 93 to 105% and from 96 to 101%, respectively. Under optimal experimental conditions the linear detection ranges were found to be 0.1–150 mg L−1 for benzoic acid and 0.05–100 mg L−1 for sorbic acid with LODs calculated from a blank test, based on 3σ, 0.03 mg L−1 and 0.02 mg L−1, respectively.