Analysis Of Food Samples Research Articles

Rapid analysis of untreated food samples by gel loading tip spray ionization mass spectrometry.

Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1μgmL-1, 0.005μgmL-1, 0.01μgmL-1; the linearity range 0.1-5μgmL-1, 0.005-0.25μgmL-1, 0.01-1μgmL-1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI-MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples.

Eco-friendly fabrication of novel hydrophobic CMC–C18@MWCNTs nano-sorbent for fat content removal in the analysis of polycyclic aromatic hydrocarbons in fatty-food samples

In this study, carbon nanohybrids was developed by hybridizing carboxymethyl cellulose (CMC) biopolymer with various amounts of multi-walled carbon nanotubes (MWCNTs: 0.2, 0.5, 1, 3, and 5%) in eco-friendly process to produce hydrophobic CMC–C18@MWCNTs, which was then used as a sorbent material for fat content in fatty food samples analysis. The hydrophobic biopolymers were synthesized using an ultrasound-assisted esterification process, and the physicochemical properties were analyzed using FT-IR, XRD, TGA, FE-SEM, and TEM. The performance of the hydrophobic nanocomposites was evaluated by assessing their ability to remove fat content during polycyclic aromatic hydrocarbon (PAHs) analysis in tuna samples. The results showed that CMC–C18–CNT0.2% provided the best peak shapes and highest recoveries for PAHs compounds, ranging between 74.3 and 89.7%, while CMC–C18–CNT5% had the lowest recoveries, ranging between 0 and 35%. Therefore, the lowest amount of MWCNTs was found to be the most efficient for removing fat content with providing high PAHs recovery, while increasing the MWCNTs percentage increased the hydrophobicity and removed PAHs analytes along with fat content. After the investigation, the method was validated using CMC–C18–CNT0.2% in three various levels: 2, 5 and 10 μg kg−1. The obtained results were satisfactory; the average recoveries for all PAHs compounds ranged between 74.3 to 89.7%, and the intra-day precision were estimated by coefficient of variation (%CV), where were less than 10% for all PAHs. The LOD and LOQ were lies between 0.33 to 0.89 μg kg−1 and 1.12 to 1.92 μg kg−1 respectively. For the calibration curve linearity, the correlation coefficient (r2) were higher than 0.999 for all PAHs. Overall, the hydrophobic CMC–C18@MWCNTs are a promising, modifiable, and useful material for fatty food analysis.

Benzidine-based chemosensors for the selective detection of phosphate, carbonate and copper ions: Applications in water and food sample analysis and on-field detection kit

In this work, benzidine-based chemosensors were synthesized. A5R1 had a cage-like structure along with 2-OH binding sites for encapsulation of Cu2+, A5R2 was found to bind with PO43¯ and CO32¯ ion; whereas A5R3 was innocent towards any cations or anions. The LOD for A5R1 with Cu2+ was found to be 2.63 ppm. A5R2 detected PO43¯ and CO32¯ with limit of detections 4.13 ppm and 5.40 ppm respectively. The interference studies indicated that there was no other ion which could restrain the analysis. Job’s Plots showcased the 1:2 binding of the receptors with the analyte ion(s). The practical applicability of the probes was demonstrated by on-field detection kit and test-strip fabrication with colour change chart. Logic gate formulation with active simulation governed by the reversibility studies envisaged the reversibility and reusability of the probe and its solicitation in making electric devices. Furthermore, spiking studies proved the application of the receptors for convenient analyte detection in real-life food and water samples.

Fluorescence turn-on detection of arsenite in rice and seawater samples using bisphosphonate-functionalised carbon quantum dots

ABSTRACT In this paper, we illustrate an efficient and simple fluorescence (FL) sensing approach for the specific determination of arsenite (As(III)) in aqueous solution by alendronate-functionalised carbon quantum dots (A-CQDs) as a turn-on fluorescent probe. A-CQDs exhibit linear FL turn-on response towards the increasing concentration of As(III) analyte with a limit of detection of 0.007 µM and a linear range of 0.03–1.87 µM. The selectivity study demonstrates that the A-CQDs are very selective for As(III) detection, even at a higher concentration of other interfering ions. The sensing pathway for the sensitivity of A-CQDs assay to quantify As(III) ions is expected to rely on the chelation-enhanced FL (CHEF) mechanism between A-CQDs and the analyte. This mechanism is verified by the density functional theory methodology. The practical application of this simple and reliable sensor is demonstrated by assaying As(III) in rice and seawater samples, which confirms that A-CQDs have good potential for real sample analysis in food and environmental samples.

A novel photoelectrochemical aptasensor based on 3D flower-like g-C3N4/BiOI p-n heterojunction for the sensitive detection of kanamycin

BackgroundKanamycin (KAN) residues in animal-derived foods continuously enter the human body, which will pose serious threats to human health such as hearing loss, nephrotoxicity and other complications. Therefore, to sensitively detect KAN residues by a reliable technology is extremely urgent in food quality and safety. Compared with traditional methods being limited by cost and complexity, photoelectrochemical (PEC) biosensors benefit from some merits such as rapid response, excellent sensitivity and good stability. In this study, the construction of a highly efficient PEC platform to realize KAN residues detection is discussed. ResultsHerein, a novel p-n heterojunction consisting of flower-like BiOI microspheres and graphite carbon nitride (g-C3N4) nanoflakes was developed to establish a PEC aptasensor for KAN detection at 0 V. The prepared g-C3N4/BiOI heterostructure showed not only significantly enhanced PEC activity due to the larger specific surface area but also greatly increased charge separation efficiency owing to the strong internal electric field. Meanwhile, using g-C3N4/BiOI as a highly efficient photoactive material for binding amine-functionalized aptamers to capture KAN, the photocurrent signals showed a ‘turn off’ mode to achieve the sensitive detection of KAN. The proposed PEC aptasensor exhibited linear response for KAN from 5 × 10−9 to 3 × 10−7 mol L−1 with a low detection limit of 1.31 × 10−9 mol L−1, and satisfactory recoveries (97.44–107.38 %) were obtained in real food samples analysis. SignificanceThis work presented a novel p-n heterojunction-based PEC aptasensor with strong selectivity and stability, rendering it allowed to detect KAN in animal-derived foods including milk, honey and pork. Additionally, the detection range satisfied the MRLs for KAN specified by the national standards, demonstrating the potential application for food analysis. The study provides a new insight into the development of efficient and practical biosensors for antibiotic residues detection.

Highly active Mn2O3-Fe3O4 catalyst with abundant metal-oxygen bonds for real time sensing of carbendazim in environmental samples

In agriculture, a benzimidazole-based fungicide of carbendazim (CBZ) is widely used for disease control in fruits and vegetables. However, its toxicity raises concerns about potential harm to humans from consuming contaminated food. In this study, we developed an eco-friendly manganese iron oxide (Mn2O3-Fe3O4) catalyst via coprecipitation, employing with high temperature annealing (MFO-A) and calcination (MFO-C) techniques. Comparative physical and chemical characterization demonstrated that MFO-A performed better than MFO-C. The prepared catalyst was employed to modify a glassy carbon electrode (GCE) in order to enable electrochemical CBZ sensing through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimized experimental condition, the sensor achieving a lower limit of detection (LOD), limit of quantification (LOQ), and sensitivity are 0.027 ng/L, 0.084 ng/L, and 1.57 µA (ng/L)–1 cm−2. The sensor demonstrated excellent selectivity, repeatability, reproducibility, and storage stability with acceptable recovery rate. The effectiveness of the present sensor was further validated through real-time analysis of environmental and food samples, highlighting its potential for enhancing environmental safety.

A dual-mode fluorometric and colorimetric sensor based on N-doped carbon dots for selective and sensitive detection of nitrite in food samples

A highly sensitive and selective nitrite sensing platform based on nitrogen-doped carbon quantum dots (N-CDs), by means of a headspace single drop microextraction process, was constructed for dual-mode fluorometric and visual colorimetric determination of nitrite. In this system, the two-channel selective sensing of nitrite was achieved at the same time, with color ranging from colorless to red and N-CDs fluorescence quenching gradually. Meanwhile, gaseous NO was generated from the redox chemical vapor generation process and further extracted into a single drop, which effectively improving the analytical sensitivity and alleviating the matrix interference. By fluorescence and colorimetry, the limits of detection were calculated to be 0.03 and 0.08 μg mL−1, respectively, while 0.8 μg mL−1 nitrite was discernable by the naked eye. This method was utilized to analysis of diversified real food samples (vegetables, milk and ham), and the results were proved to be nearly consistent with a standard method. Furthermore, the storage conditions of vegetable juice have also been explored.

Sensitive and selective antioxidant curcumin analysis using anionic surfactant modified glassy carbon electrode

This paper presents a sensitive and selective curcumin (CCM) voltammetric procedure using a glassy carbon electrode covered with asodium dodecyl sulfate layer (GCE/SDS) in 0.2 M CH3COOH. The developed sensor and the behavior of CCM on its surface were investigated by voltammetric and impedance techniques. According to the results, the GCE/SDS shows electrocatalytic properties in relation to oxidation of CCM and the redox Fe(III)/Fe(II) system. The concurrent process of preparing sensors and conducting CCM measurements is marked by its ease of implementation, minimal reagent usage, and affordability. The use of CCM accumulation at 0 V for 120 s allows gaining the linearity of the calibration curve from 0.001 to 20.0 nM, with an extremely low LOD of 0.00027 nM. Ultimately, the established procedure was effectively employed for the analysis of food samples, including spice extracts and energy shots, and the results are consistent with chromatography measurements.

Natural Polymer Encapsulated Zeolitic Imidazolate Framework-12 Composite toward Electrochemical Sensing of Antitumor Agent.

Encapsulation of natural polymer pectin (Pec) into a zeolitic imidazolate framework-12 (ZIF-12) matrix via a simple chemical method toward anticancer agent gallic acid (GA) detection is reported in this work. GA, a natural phenol found in many food sources, has gained attention by its biological effects on the human body, such as an antioxidant and anti-inflammatory. Therefore, it is crucial to accurately and rapidly determine the GA level in humans. The encapsulation of Pec inside the ZIF-12 has been successfully confirmed from the physiochemical studies such as XRD, Raman, FTIR, and XPS spectroscopy along with morphological FESEM, BET, and HRTEM characterization. Under optimized conditions, the Pec@ZIF-12 composite exhibits wide linear range of 20 nM-250 μM with a detection limit of 2.2 nM; also, it showed excellent selectivity, stability, and reproducibility. Furthermore, the real sample analysis of food samples including tea, coffee, grape, and pomegranate samples shows exceptional recovery percentage in an unspiked manner. So far, there is little literature for encapsulating proteins, enzymes, metals, etc., that have been reported; here, we successfully encapsulated a natural polymer Pec inside the ZIF-12 cage. This encapsulation significantly enhanced the composite electrochemical performance, which could be seen from the overall results. All of these strongly suggest that the proposed Pec@ZIF-12 composite could be used for miniaturized device fabrication for the evaluation of GA in both home and industrial applications.

Assessment of food safety in Baghdad, Iraq: A two-year analysis of food samples received by the nutrition research institute

Assessment of food safety in Baghdad, Iraq: A two-year analysis of food samples received by the nutrition research institute

Real-time, ultra-sensitive and label-free detection of OTA based on DNA aptamer functionalized carbon nanotube field-effect transistor

Ochratoxin A (OTA), widely recognized as a mycotoxin contaminant across various food products, poses significant health risks attributed to its nephrohepatotoxic and carcinogenic effects. Consequently, detecting OTA is crucial for ensuring food safety and preventing mycotoxicosis. In our study, we employed a carbon nanotube field-effect transistor (CNT FET) functionalized with DNA aptamers for targeted OTA detection. The sensor achieved a remarkably low detection threshold of 0.2 femtomolars (fM) in phosphate-buffered saline (PBS), enabling real-time detection of OTA over a broad concentration spectrum spanning from 8 fM to 80 pM. This research confirmed the sensor’s superior selectivity by effectively distinguishing OTA from non-target fungal toxins and showcased its rapid analysis capabilities across diverse complex matrices. Utilizing homogenized liquids from ten representative food samples for analysis, the sensor delivered real-time responses within 100 s, accurately identifying varying OTA concentrations down to 80 fM. In conclusion, this biosensor provides a label-free, highly sensitive, and rapid detection method for OTA, introducing novel solutions for effective mycotoxin surveillance in food safety. This biosensor also paves the way for the creation of a multiplex platform for concurrent monitoring of multiple fungal toxins.

Gold Nanoparticle-Coated Magnetic Graphene Oxide as a Dual-Mode Immunochromatographic Biosensor for Enrofloxacin Residue Analysis in Food Samples

Gold Nanoparticle-Coated Magnetic Graphene Oxide as a Dual-Mode Immunochromatographic Biosensor for Enrofloxacin Residue Analysis in Food Samples

Texture Analysis of Food Samples Used for the Evaluation of Masticatory Function.

Introduction Food questionnaire surveys are often used to evaluate masticatory function. In daily clinical practice in Japan, a survey is performed using a list of food groups suitable for the Japanese diet. The foods on the list were categorized into five food groups based on their mastication index. The patient's masticatory function is determined by the food groups that can be eaten. The masticatory index, which indicates chewability, was defined based on the percentage of 110 denture wearers who responded that they could eat food normally. A survey with this list is useful because of its simplicity; however, there is a lack of objective data on the physical properties of food samples. Consequently, to make the results of the food questionnaire survey more objective indicators, we performed a texture analysis of the food samples on the list. Methods We performed a texture analysis of 93 samples from 77 food items on the list. Compression tests were performed using a texture analyzer, and hardness, cohesiveness, adhesiveness, viscosity, and gumminess were calculated by a texture profile analysis. Results Even with the same ingredients, the results differed depending on the presence or absence of food skin, the direction of pressing (vertical or horizontal), cooking methods, and temperature differences. However, the masticatory index was negatively correlated with hardness (-0.4157, p<0.001) and gumminess which is determined as the product of hardness×cohesiveness (-0.4980, p<0.001). Conclusion This study suggests that the masticatory index indicating chewability may be related to the hardness and cohesiveness of food samples. Even for foods with the same hardness, the degree of difficulty in forming a food mass is expected to vary depending on differences in cohesiveness. Moreover, the presence or absence of food skin, the direction of food fibers, cooking methods, and temperature differences change the physical properties of the food. Therefore, the composition and structure of the foods or eating habits of patients should be taken into consideration when conducting a food questionnaire survey.

Fluorescent Molybdenum Disulfide Quantum Dots for Sensitive Detecting Curcumin in Food Samples through FRET Mechanism.

A selective and sensitive fluorometric assay was developed for specific determination of curcumin (Cur) based on fluorescence resonance energy transfer (FRET) between molybdenum disulfide quantum dots (MoS2 QDs) and Cur. The MoS2 QDs were prepared via a one-step hydrothermal protocol using sodium molybdate dihydrate, L-cysteine (Cys) as precursors, and sodium cholate (SC) as a modification agent. The as-prepared MoS2 QDs possessed maximum fluorescence emission at 460nm with a 20% of fluorescence quantum yield (FQY). It was found that the fluorescence of MoS2 QDs could be quantitatively quenched by Cur through FRET mechanism. Therefore, Cur could be detected in the range of 0.1-20µg mL- 1 with a detection limit of 5 ng mL- 1. Additionally, the developed MoS2 QDs based fluorescent assay has been successfully applied for real food sample analysis with satisfactory results.

Tailored fluorophore design: Enhancing selectivity for cyanide ion sensing in water and food samples, and innovative device development

A rigid fluorophore unit of Julolidine/coumarin fused with an indolium-conjugated system was built for the immediate and effective recognition of cyanide ions in a 90 % aq. DMSO solution. The probes are capable of displaying better sensitivity/selectivity for the cyanide ion over a wide range of other interfering ions. The probe JI showed an instant colorimetric variation, whereas the modified probe JCI showed both colorimetric and fluorimetric variation with cyanide ion. The observed detection limit values indicated excellent sensitivity of the probe to the cyanide ion. HRMS and 1H NMR studies confirmed that the mechanism of detection of CN− is via the nucleophilic attack on the electron-deficient indolium moiety of the molecule. Moreover, the probes are well proficient in selective recognition of cyanide in various real time applications (test strips, electronic sensor kit, food and water sample analysis).

A modified Prussian blue biosensor with improved stability based on the use of self-assembled monolayers and polydopamine for quantitative L-glutamate detection.

Aminiature L-glutamate (L-Glu)biosensor is describedbased on Prussian blue (PB) modification with improved stability by using self-assembled monolayers (SAMs) technology and polydopamine (PDA). A gold microelectrode (AuME) was immersed in NH2(CH2)6SH-ethanol solution, forming well-defined SAMs via thiol-gold bonding chemistry which increased the number of deposited Prussian blue nanoparticles (PBNPs) and confined them tightly on the AuME surface. Then, dopamine solution was dropped onto the PBNPs surface and self-polymerized into PDA to protect the PB structure from destruction. The PDA/PB/SAMs/AuME showed improved stability through CV measurements in comparison with PB/AuME, PB/SAMs/AuME, and PDA/PB/AuME. The constructed biosensor achieved a high sensitivity of 70.683 nAµM-1cm-2 in the concentrationrange 1-476µM L-Gluwith a low LOD of 0.329µM and performed well in terms of selectivity, reproducibility, and stability. In addition, the developed biosensor was successfully applied to the determination of L-Glu in tomato juice, and the results were in good agreement with that of high-performance liquid chromatography (HPLC). Due to its excellent sensitivity, improved stability, and miniature volume, the developed biosensor not only has a promising potential for application in food sample analysis but also provides a good candidate for monitoring L-Glu level in food production.

A novel premixing strategy for highly sensitive detection of nitrite on paper-based analytical devices

BackgroundNitrite has been involved in many food processing techniques and its excessive consumption is closely related to the development of different diseases. Therefore, highly sensitive detection of nitrite is significant to ensure food safety. ResultThis study presents a simple and novel strategy for the highly sensitive detection of nitrite in food using paper-based analytical devices (PADs). In this proposed strategy, the nitrite present in the sample undergoes efficient diazotization when initially mixed with sulfanilamide solution before reacting with N-(1-naphthyl) ethylenediamine dihydrochloride (NED) coated on the detection region of the PAD, leading to the maximum production of colored azo compounds. Specifically, within the concentration range of 0.1–20 mg/L, the LOD and LOQ for the nitrite assay using the premixing strategy are determined as 0.053 mg/L and 0.18 mg/L, respectively which significantly surpass the corresponding values of 0.18 mg/L (LOD) and 0.61 mg/L (LOQ) achieved with the regular Griess reagent analysis. SignificanceThe study highlights the critical importance of the premixing strategy in nitrite detection. Under optimized conditions, the strategy demonstrates an excellent limit of detection (LOD) and limit of quantification (LOQ) for nitrite detection in eight different meat samples. In addition to its high precision, the strategy is applicable in the field of nitrite analysis. This strategy could facilitate rapid and cost-effective nitrite analysis in real food samples, ensuring food safety and quality analysis.

A dual-mode fluorometric and smartphone-based colorimetric sensor for cyanide detection using tungsten disulfide quantum dots and silver nanoparticles

In this study, tungsten disulfide quantum dots (WS2 QDs) and silver nanoparticles (AgNPs) were applied to establish a dual-mode fluorometric and smartphone-based colorimetric sensor for the determination of cyanide ions (CN⁻). We indicated that the fluorescence intensity of WS2 QDs was quenched by AgNPs as a result of the inner filter effect (IFE) mechanism. Moreover, the quenched fluorescence intensity of WS2 QDs switched on again in the presence of CN⁻ due to the interaction between AgNPs and CN⁻, leading to destroy AgNPs, diminishing their yellow color and reducing their IFE on WS2 QDs. Based on these facts, we established a turn-off-on fluorometric (with a range of 0.5–30 and detection limits of 0.17 µM) and smartphone-based colorimetric sensor (with 5–500 µM and detection limits of 1.2 µM) for CN⁻ measurement. The sensor was exploited for CN⁻ analysis in water and food samples with satisfactory results. The established dual sensor benefits from both methods advantages such as the high sensitivity of fluorometric sensors as well as simple and visual detection of smartphone-based colorimetric sensors. Additionally, our developed smartphone-based colorimetric sensor can be used as a portable sensor for the sensitive, rapid and low-cost analysis of CN⁻ in the field.

Improved Indophenol Titration Method for Ascorbic Acid Using a Dropper and Electronic Balance: Enhanced Convenience and Efficiency

The analysis of ascorbic acid using the 2,6-dichloroindophenol (DCIP) titration method is a well-established technique, but requires the skilled handling of a burette for accurate measurements. In the present study, we propose a modified DCIP titrimetric method that replaces the burette with a dropper and employs an electronic balance to measure the titrated amount by weight. The dropper used can be flexibly selected, allowing for a wide range of drop sizes, from large to very small. This modification offers several advantages, including lower skill requirements, a 43% reduction in the analysis time, a 50% decrease in sample/reagent consumption, and the ability to prepare DCIP standard solutions tailored to the concentration of ascorbic acid in the sample being analyzed. Our analysis of several food samples using this improved method showed that inherent issues of the DCIP method, such as determining the titration end point, could not be resolved. Nevertheless, the improved titration method remains more convenient and adaptable than the original approach using a burette, enabling quick and accurate analysis, especially for unskilled analysts.

An introductory review on the application of principal component analysis in the data exploration of the chemical analysis of food samples.

Principal component analysis (PCA) is currently one of the most used multivariate data analysis techniques for evaluating information from food analysis. In this review, a brief introduction to the theoretical principles that underlie PCA will be given, in addition to presenting the most commonly used computer programs. An example from the literature was discussed to illustrate the use of this chemometric tool and interpretation of graphs and parameters obtained. A list of recently published articles will also be presented, in order to show the applicability and potential of the technique in the food analysis field.