Rapid Quantitative Analysis of Acetamiprid Residue in Crude Palm Oil Using Sers Coupled with Random Frog (Rf) Algorithm
SSRN Electronic Journal
Translocation of pesticide residues in cabbage
Effect of sequential multi-frequency ultrasound washing processes on quality attributes and volatile compounds profiling of fresh-cut Chinese cabbage
LWT, 2019
Abstract The objective of the current investigation was to assess the microbial quality, physicoc... more Abstract The objective of the current investigation was to assess the microbial quality, physicochemical parameters, volatiles profile and sensory quality of fresh-cut Chinese cabbage samples exposed to dual frequency ultrasound (DFU1: 20–40 kHz; DFU2: 20–60 kHz; and DFU3: 40–60 kHz) and triple frequency ultrasound (TFU: 20–40–60 kHz) washing processes. The natural microbiota (total bacteria, yeasts and molds), physicochemical quality (instrumental colour, texture, electrolyte leakage, and microstructure), volatile compounds and sensorial quality (texture, colour, odour, appearance and general acceptability) were determined. Counts of total bacteria, yeast and molds were significantly reduced (P 1) and were considered as aroma active compounds (AACs) contributing substantially to the core aroma profile of the Chinese cabbage. Finally, DFU washing according to an affective sensory tests on treated samples, presented positive sensory characteristics with better general acceptability compared to TFU washing.
Dietary exposure to chlorinated pesticide residues in fruits and vegetables from Ghanaian markets
Journal of Food Composition and Analysis, 2016
Abstract Analysis of 400 fruit and vegetable samples obtained from open and closed markets in Acc... more Abstract Analysis of 400 fruit and vegetable samples obtained from open and closed markets in Accra, Ghana was carried out employing a multi-residue method based on solid-phase extraction followed by gas chromatography–mass spectrometry. Generally, the data showed that most of the fruit and vegetable samples analysed contain residues of the monitored pesticides below the accepted maximum residue limit ( MRL ) as adopted by the Food and Agricultural Organization/World Health Organization (FAO/WHO) Codex Alimentarius Commission (CAC), although some pesticide residues were not detected in some of the fruit and vegetable samples. The results obtained further revealed that 20% of the fruit and vegetable samples were above MRL , 73% were below MRL and 7% contained no detectable level of the monitored pesticides. Estimation of dietary intake of pesticides from fruit and vegetables revealed that, pesticides detected in fruits and vegetables did not cause dietary intake risks. The results recommend the need for regular monitoring for pesticide residues of a greater number of samples for long periods, especially in fruit and vegetables, to protect consumers’ health.
The unambiguous identification and quantification of hazardous materials is of increasing importa... more The unambiguous identification and quantification of hazardous materials is of increasing importance in many sectors such as waste disposal, pharmaceutical manufacturing, and environmental protection. One particular problem in waste disposal and chemical manufacturing is the identification of solvents into chlorinated or non-chlorinated. In this work we have used Raman spectroscopy as the basis for a discrimination and quantification method for chlorinated solvents. Raman spectra of an extensive collection of solvent mixtures (200+) were collected using a JY-Horiba LabRam, infinity with a 488 nm excitation source. The solvent mixtures comprised of several chlorinated solvents: dichloromethane, chloroform, and 1,1,1-trichloroethane, mixed with solvents such as toluene, cyclohexane and/or acetone. The spectra were then analysed using a variety of chemometric techniques (Principal Component Analysis and Principal Component Regression) and machine learning (Neural Networks and Genetic Programming). In each case models were developed to identify the presence of chlorinated solvents in mixtures at levels of ~5%, to identify the type of chlorinated solvent and then to accurately quantify the amount of chlorinated solvent.
Journal of the American Oil Chemists' Society, 1983
A screening method has been developed for simultaneous determination of aflatoxin B1 and ochratox... more A screening method has been developed for simultaneous determination of aflatoxin B1 and ochratoxin A in olive oil. The technique includes extraction of both mycotoxins with aqueous methanol, clean‐up using lead acetate, partitioning in chloroform, and thin layer chromatography. The detection limits achieved are, respectively: 4 μg aflatoxin B1 and 40 μg ochratoxin A/kg. 60 samples of crude farm olive oil were analyzed using this method: three of them contained traces of ochratoxin A while none was contaminated with aflatoxin B1.
SERS-based sensor coupled with multivariate models for rapid detection of palm oil adulteration with Sudan II and IV dyes
Journal of Food Composition and Analysis
Fraud detection in crude palm oil using SERS combined with chemometrics
Food Chemistry
Edible crude palm oil (CPO) is a vital oil utilized in various industries, including food, pharma... more Edible crude palm oil (CPO) is a vital oil utilized in various industries, including food, pharmaceuticals, and domestic cooking. Unfortunately, reports of CPO adulteration with harmful Sudan dyes have surfaced over the years. Surface-enhanced Raman spectroscopy (SERS) and chemometrics were employed to detect Sudan dyes adulteration in CPO within 900 - 1800 cm- 1 Raman peak. The concentration of Sudan dyes detected in CPO samples ranged between 0.005 and 4 ppm. The principal component analysis (PCA) model detected Sudan II and Sudan IV in CPO with 99.88 and 99.90% accuracy. Linear discriminant analysis (LDA) and K-Nearest Neighbors (KNN) also recorded high detection rates of Sudan II and IV dyes in CPO. Sudan II and IV dyes could be detected at 0.0028 ppm and 0.0019 ppm by this sensor. The performance of the Au@Ag SERS sensor was comparable to that of HPLC. This study proved SERS and chemometrics can be used to authenticate edible CPO.
Rapid Detection and Prediction of Norfloxacin in Fish Using Bimetallic Au@Ag Nano-Based SERS Sensor Coupled Multivariate Calibration
Food Analytical Methods
Norfloxacin is an antibiotic in the fluoroquinolone family licenced for use in animals. However, ... more Norfloxacin is an antibiotic in the fluoroquinolone family licenced for use in animals. However, residues in animal products can have negative consequences for consumers. As a result, residue detection in various food matrices must be considered. Norfloxacin accumulates in animal-derived foods, causing deleterious consequences in humans such as foetal deformity, renal failure and drug resistance. A built-in SERS-Au@Ag nanosensor coupled with GA-PLS was used to rapidly detect norfloxacin in the specimen of the spiked fish muscles due to the threat to human lives. A detection limit of 2.36 × 10−5 μg/mL was realized in the spiked fish muscle sample for norfloxacin compared to the European Commission’s maximum threshold level of 100 μg/kg, indicating the sensor’s ability to detect and quantify norfloxacin at a relatively lower level. The recovery rates (RC) and coefficient of variation (CV) measured in the spiked fish muscle samples for norfloxacin analytes and their standard solutions were between 99.70–105.00% and 0.17–5.21%, respectively. The low CV values imply the reproducibility of the obtained data. The constructed model recorded residual predictive deviations (RPD) greater than three (3), demonstrating the robustness and resilience of the developed genetic algorithm-partial least squares (GA-PLS) model. GA-PLS-built models predicted all results within 4.07 s, which indicates the nanosensor’s ability to rapidly detect norfloxacin in fish to guarantee safety and public health. The SERS probe holds promise for rapid quantification of norfloxacin at microgram per milliliter level in fish to guarantee safety in commerce.
Thunnus albacares protein-mediated synthesis of water-soluble Copper nanoclusters as sensitive fluorescent probe for Ferric ion detection
Journal of Molecular Structure, 2022
Evaluating the Effects of Gamma Irradiation and Storage Period on the Phytochemical Stability of Some Selected Spices on the Ghanaian Market
The aim of this study was to assess the effect of gamma irradiation treatment and storage period ... more The aim of this study was to assess the effect of gamma irradiation treatment and storage period on the phytochemical stability of some spices ( Eugenia caryophyllata , Xylopia aethiopica and Aframomum melegueta ) on the Ghanaian market. The radiation processing was carried out on dose levels of 0, 5, 10 and 20kGy over a period of four months. The irradiated and control samples were analyzed for Total flavonoids, Total Phenolics, Vitamin C and DPPH radical-scavenging activity for both aqueous and ethanolic extracts with the exception of Vitamin C. The study revealed that gamma irradiation did not compromise on the innate phytochemical stability of the spice samples; however storage period showed significant effects on the phytochemical indices of the spice
Journal of Photochemistry and Photobiology A: Chemistry, 2020
Facile preparation of fluorescent carbon quantum dots from denatured sour milk and its multifunct... more Facile preparation of fluorescent carbon quantum dots from denatured sour milk and its multifunctional applications in the fluorometric determination of gold ions, in vitro bioimaging and fluorescent polymer film
Aims: Soluble solids content (SSC) is an essential indicator for evaluating the internal quality ... more Aims: Soluble solids content (SSC) is an essential indicator for evaluating the internal quality of fresh jujube, which can be used to classify the quality grade of fresh jujube. Methods: In this study, SSC was determined as the research index of the internal quality in Lingwu long jujube to classify their quality grade. The online rapid nondestructive grading device for jujube quality was designed, including the design of the hardware system and a software system. The performance of the device was evaluated by additional samples. Results: By grading external samples, the correct rate of classification of SSC was 86.7% (the first, second, and third grade were 100, 85.7, and 71.4%, respectively), and the residual predictive deviation (RPD) value of optimal model was 2.8 (>2.5). Conclusions: The acquired results revealed that, the device could be used in production. Practical Applications In this study, we developed an online nondestructive sugar grading device for fresh jujubes, including the design of hardware systems, the development of software systems. NIR spectroscopy technique coupled with chemometric selection method of characteristic variables were used to build a prediction model for SSC in fresh jujubes. In addition, the model and device were evaluated by external samples, the accuracy of the result was high, and it could be used for the grading of the sugar content of fresh jujube and could potentially extend the quality parameter grading applied to other fruit. This study provided the basis for the development of nondestructive rapid grading system related to the quality of fruit and vegetable. 1 | INTRODUCTION The jujube (Zizyphus jujube Mill) fruit belongs to the genus Ranunculaceae, which is native to China and has a long history of cultivation. Jujube is rich in sugar, fat, protein, minerals, vitamins, and other nutrients (
Near-infrared (NIR) spectroscopy as an emerging analytical technique was used for the first time ... more Near-infrared (NIR) spectroscopy as an emerging analytical technique was used for the first time to quantitatively detect the watercore degree and soluble solids content (SSC) in apple. To reduce the data processing time and meet the needs of practical application, the variable selection methods including synergy interval (SI), successive projections algorithm (SPA), genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS) were used to identify the characteristic variables and simplify the models. The spectral variables closely related to the apple bioactive components were used for the establishment of the partial least squares (PLS) models. The predictive correlation coefficient (R p), root mean square error of prediction (RMSEP), and residual predictive deviation (RPD) were used to estimate the performance of the models. The CARS-PLS models displayed the best prediction performance using 600-1000 nm spectra with R p , RMSEP, and RPD values of 0.9562, 1.340% and 3.720 for apple watercore degree; 0.9808, 0.327 o Bx and 4.845 for apple SSC, respectively. These results demonstrate the potential of the NIR transmittance spectroscopy technology for quantitative detection of SSC and watercore degree in apple fruit.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
We investigated the impact of sonochemical action and the reaction of Hermetia illucens larvae me... more We investigated the impact of sonochemical action and the reaction of Hermetia illucens larvae meal protein (HILMP) as regards enzymolysis under varied enzyme concentration and temperature to explain the mechanism and effect of sonication on molecular conformation, limits of kinetics, free-Gibbs energy, and antioxidative capacity. Control treatment was used for comparison. The results showed sonochemical treatment enhanced HILMP-enzymolysis efficiency at various enzyme volume, and temperature. Enzymolysis-kinetics revealed sonochemical treatment increased the rate constant (p < .05) by 17.21%, 25.06%, 26.91%, and 41.38% at 323, 313, 303, and 293 K, respectively. On free-Gibbs, sonochemical treatment reduced the reactantsreactivity energy, enthalpy, and entropy by 30.53%, 35.05%, and 10.71%, respectively (p < .05). Changes in spectra of UV and fluorescence, and micrographic imaging indicated alterations of HILMP by sonochemical treatment. Antioxidative activity of sonochemically-treated HILMP increased, compared to control. Thus, sonochemical treatment may be beneficial in the production of edible insect proteins with smaller molecular weights for different food and/or pharmaceutical applications. Practical applications Sonochemical pretreatment of HILMP positively impacted it enzymolysis rate-reaction, stability of reaction products, structure, and bioactivity. Thus, the technique may be beneficial to industry in the processing/development of new (bioactive/pharmaceutical) products involving enzymolysis of edible insects (e.g., Hermetia illucens) protein; particularly at such a time where edible insects are projected to be a source of protein for human nutrition and livestock in the next few years.
Model development for soluble solids and lycopene contents of cherry tomato at different temperatures using near-infrared spectroscopy
Postharvest Biology and Technology, 2019
Abstract The near-infrared (NIR) spectrometer is a powerful tool for rapid nondestructive testing... more Abstract The near-infrared (NIR) spectrometer is a powerful tool for rapid nondestructive testing of fruit, foodstuff and agricultural products in the laboratory. However, traditional NIR spectrometers are large and inconvenient to implement for online detection, and it is sensitive to external environmental factors such as temperature, which can affect products with high water content and decrease accuracy of measurements. A mixed temperature correction method and external parameter orthogonal (EPO) method combining portable NIR spectrometer, in terms of applicability, complexity and predictive performance of the algorithm, was used to reduce the effect of temperature changes on the NIR spectra of soluble solids and lycopene in cherry tomatoes. Of a total of 176 samples, 120 and 840 spectra for 120 samples were tested at 5, 10, 15, 20, 25, 30 and 35 °C. The remaining 56 samples were used to test the prediction effect of samples at different temperatures. The EPO method has better prediction results than the mixed temperature correction model, for external multi-temperature samples, the R P of the soluble solids content was 0.8988, and the RMSEP was 0.292%, the R P of the lycopene content was 0.8023 and the RMSEP was 7.45 mg/kg, indicating that the EPO method had a good correction effect for temperature. Moreover, fewer samples were required for modeling. A portable NIR spectrometer that was developed by the EPO method revealed no significant difference between the predicted value and the standard value of 15 external samples by t-test. Therefore, the EPO method can be used to reduce the effect of temperature on the NIR spectra of cherry tomatoes and is of great significance for the real-time online detection of the fruit by a portable NIR spectrometer, and it may be useful for online rapid detection of the internal quality of other fruit.
Hermetia illucens (edible insect) larvae protein, and hydrolysates were prepared using three pret... more Hermetia illucens (edible insect) larvae protein, and hydrolysates were prepared using three pretreatment modes (conventional, fixed-frequency ultrasonic, and sweep-frequency). Protein subunit scores, microstructure, antioxidative activity, and techno-functional property of the respective isolates and hydrolysates were investigated. Alkaline protease hydrolysis significantly enhanced protein solubility, but impaired the emulsifying property and foaming stability. Isolates and hydrolysates treated by ultrasound exhibited highest antioxidative effect, and showed excellent solubility and foam expansion over wide (2-12) pH, likened the conventional. Ultrasonic, particularly sweep-frequency, treated hydrolysates overall showed superior solubility, foam, and antioxidative (ABTS, Superoxide scavenging, and Ferric-reducing) capacity than the remaining modes and isolates (p<0.05). Treatment type influenced microstructure, functional attributes and antioxidative capacity of hydrolysates and isolates. Thus, functional/antioxidative property could be improved or modified for different food applications based on elected treatment. H. illucens isolate and hydrolysate preparations thereof could suitably be used in development of novel food formulations.
The study investigated the effect of sonication conditions on antioxidant activity of Hermetia il... more The study investigated the effect of sonication conditions on antioxidant activity of Hermetia illucens larvae meal protein hydrolysates. Three-factor three-level: pH (7-9), time (10-30 min), and temperature (25-55°C) were optimized. Box-Behnken's design was applied to optimize sonication treatment. Ferrous ion chelating activity (ICA), DPPH-radical scavenging activity (DPPHRSA), Hydroxyl radical scavenging activity (HRSA), and cupric ion chelating activity (CCA) were considered as responses. Findings demonstrated that sonication preceding enzymolysis significantly impacted on ICA, DPPHRSA, HRSA, and CCA. ANOVA showed the determination coefficient (R 2) were 0.98 (ICA), 0.99 (DPPHRSA), 0.98 (HRSA), and 0.88 (CCA); demonstrating that the models were reasonably fit with experimental results. Optimum sonication conditions were pH (9), time (29.84 min), and temperature (54.93°C). For these conditions, the experimental data obtained [ICA (37.84%), DPPHRSA (43.19%), HRSA (71.01%), and CCA (68.93%)] were consistent with predicted values, higher than control, and supported by protein subunits, fluorescence spectra and microstructure. Practical applications With a rich nutrient profile, edible insects are potential ingredient for food applications. Hermetia illucens is one of the most encouraging edible insect species for incorporation in food products as it has several benefits to the environment, coupled with the already available knowhow for their rearing. With the prediction that in the next few decades insects will be reliable source of protein for humans and livestock, it is logical that the antioxidants activity of insect larvae meal proteins are investigated for new product development. Ultrasound is reported to enhance enzyme action in the preparation of bioactive hydrolysates/peptides. The present study showed that the use of ultrasonication pretreatment in the enzymatic hydrolysis of HILMP to generate hydrolysates with antioxidant constituents was efficient (likened to conventional approach). The study outcome could help the food and/or pharmaceutical industry to advance new bioactive products/ functional foods from HILMP hydrolysates.
A system composed of upconversion nanoparticles (UCNPs) and N,N-diethyl-p-phenylenediamine (EPA) ... more A system composed of upconversion nanoparticles (UCNPs) and N,N-diethyl-p-phenylenediamine (EPA) is shown to be a useful probe for highly sensitive and selective fluorometric determination of ferric ion. The fluorescence of the UCNPs (under the 980 nm excitation) has peaks at 546, 657, 758 and 812 nm. EPA is readily oxidized by Fe(III) to generate a dye with a peak at 552 nm. This causes an inner filter effect on the fluorescence peaks at 546 nm, whereas the emissions at 657, 758 and 812 nm remained unchanged. Therefore, the iron concentration can be quantified by measurement of the ratio of fluorescence at 546 and 758. Under optimal condition, the ratio drops linearly in the 0.25 to 50 μM. Fe(III) concentration ranges, with a detection limit of 0.25 μM. The method is highly selective and was applied to the analysis of spiked samples (wastewater) where it gave recoveries of between 100.9 and 107.3%; and RSD values between 0.8 and 1.4%. Results are approximately the same as those obtained by AAS.
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