Food Samples Research Articles

Design and fabrication of self-calibration colorimetric/fluorescence/SERS tri-modal optical sensor for highly rapid and accurate detection of mercury ions in foods

The improvement of detection accuracy without loss of rapidity and sensitivity by optical sensors in complex food analysis is still full of challenges owing to the matrix interference. Herein, a novel and simple self-calibration colorimetric/fluorescence/surface-enhanced Raman spectroscopy (SERS) tri-modal optical sensor based on aminated Rhodamine 6G (R6G-NH2) was developed for highly rapid, sensitive, and accurate detection of Hg2+ in food samples. The high recognition specificity of R6G-NH2 for Hg2+ can be achieved through the metal chelation interaction between Hg2+ and -NH2, -COOH groups in R6G-NH2 with formation of R6G-NH2-Hg2+-R6G-NH2 complex. The DFT and FDTD simulations were adopted to confirm the theoretical feasibility in Hg2+ detection by tri-modal optical. Under the optimum conditions, the analytical method based on self-calibration tri-modal optical sensor for Hg2+ detection was established with promising properties (rapidity, linearity, linear range, LOD, and LOQ), providing a strategy in rapid, selective, sensitive, and accurate detection for food safety.

Genotypic Antimicrobial Resistance Profiles of Diarrheagenic Escherichia coli and Nontyphoidal Salmonella Strains Isolated from Children with Diarrhea and Their Exposure Environments in Ethiopia.

Antimicrobial resistance (AMR) poses a significant global threat, particularly in low- and middle-income countries, such as Ethiopia, where surveillance is limited. This study aimed to predict and characterize the AMR profiles of diarrheagenic Escherichia coli (DEC) and nontyphoidal Salmonella (NTS) strains isolated from human, animal, food, and environmental samples using whole genome sequencing. A total of 57 NTS and 50 DEC isolates were sequenced on an Illumina NextSeq 550. The ResFinder and PointFinder tools were employed to identify antimicrobial resistance genes (ARGs) and point mutations. Salmonella serotypes were determined using SeqSero. The analysis identified at least one ARG in every NTS sample and 78% of the DEC isolates, with 22 distinct ARGs in the NTS samples and 40 in the DEC samples. The most prevalent ARGs were aac(6')-Iaa and aph(3')-Ib, which predict aminoglycoside resistance in 100% of NTS and 54% of DEC isolates, respectively. Other commonly identified ARGs include sul2, aph(6)-Id, blaTEM-1B , and tet(A), which confer resistance to folate inhibitors, aminoglycosides, β-lactams, and tetracycline. Some ARGs predicted phenotypic multidrug resistance in both DEC and NTS isolates. All identified β-lactam ARGs, except for blaTEM -1D, conferred resistance to more than three antibiotics. Interestingly, blaCTX- M-15 was found to confer resistance to nine antibiotics, including third-generation cephalosporins, in 18% of DEC and 3.5% of NTS isolates. DEC isolates from children exhibited the highest ARG diversity. Notably, genes such as aph(3″)-Ib, aph(6)-Id, sul2, and tet(A) were detected across all sample types, including water sources, although some ARGs were exclusive to specific sample types. Point mutations mediating AMR were detected in several genes, with mutations associated with nucleotide substitution being the most frequent. This genotypic AMR profiling revealed the presence of widespread drug-resistant NTS and DEC strains in Ethiopia. Robust and sustained AMR surveillance is essential for monitoring the emergence and spread of these resistant pathogens.

How does viewing food products in 2D or 3D affect consumer evaluations?

This study examines the influence of changes in visual information (2D vs. 3D) and product characteristics (healthy vs. unhealthy) on consumer purchase intention, expected satiety, and expected volume with regard to food products. The participants were asked to answer a questionnaire for each food sample displayed in 2D or 3D. The results reveal that the 3D food model has significantly higher scores for expected volume and satiety than does the 2D model, along with a significant interaction between visual information and product characteristics. For healthy foods, the expected volume, expected satiety, and purchase intention were significantly higher in the 2D than in the 3D model. For unhealthy foods, scores for the three variables were significantly higher in the 3D than in the 2D food model. This indicates an inverse relationship based on the healthiness of the food product. The study posits that changing the visual information from 2D to 3D strengthened the image of healthy and unhealthy foods as having low and high volumes, respectively, resulting in a more favorable purchase intention. The results of this study advance our understanding of the applicability of different image types when promoting food products, thereby enabling and guiding well-informed decisions of online retailers and other stakeholders in the design of food products for advertisements and other purposes in the food service industry.

Locally acquired typhoid fever outbreak linked to chronic carriage in Ottawa, Canada, 2018-2022.

In Canada, Salmonella enterica serovar Typhi infections are uncommon and typically travel-related. In November 2021, Ottawa Public Health identified a link between two typhoid fever cases, with no recent history of international travel, to the same grocery store ready-to-eat counter. This report describes the outbreak response to a rare occurrence of chronic S. Typhi carriage in Ottawa, Ontario, Canada and provides recommendations for investigations of small-scale protracted outbreaks. We administered exposure questionnaires using a single interviewer approach, tested stool samples of contacts and food handlers, inspected food premises, collected food samples and reviewed takeout receipts. Social network, spatial and whole genome sequencing analyses were used to investigate additional possible links between cases. Seven people with typhoid fever and onset from October 2018 to May 2022 were linked to an asymptomatic chronic S. Typhi carrier. Whole-genome sequencing confirmed that all eight isolates matched the outbreak cluster. All cases and carrier resided within an eight km radius in Ottawa. The chronic carrier worked as a food handler at various locations of a grocery store chain, including the implicated ready-to-eat counter. Transmission occurred via food handling, shared workspaces and social and household networks. The chronic carrier was excluded from food handling until successful completion of treatment and clearance testing. We overcame the challenges of a small but prolonged outbreak by identifying an asymptomatic carrier using a multi-method approach including whole genome sequencing and social network analysis.

Electrochemical determination of 5-heneicosylresorcinol using a disposable molecularly imprinted polymer-modified screen-printed electrode

Alkylresorcinols serve as critical biomarkers for whole-wheat grains, and their precise analysis is essential for authenticating and monitoring the quality of whole-wheat products. In this study, we developed a novel electrochemical sensor by using a disposable screen-printed electrode for the sensitive and selective detection of 5-heneicosylresorcinol (AR21). To enhance the sensor’s sensitivity and selectivity, multilayered Ti3C2Tx (m-Ti3C2Tx) nanomaterials were incorporated into the electrode in conjunction with molecularly imprinted polymers. Under optimized conditions, the sensor exhibited a linear detection range of 0.005 to 100 mg·L−1, with a detection limit of 3.98 μg·L−1 for AR21. Furthermore, the sensing platform demonstrated remarkable selectivity for AR21 when compared to structurally similar compounds, along with excellent reproducibility and stability. Validation studies with real wheat food samples confirmed the effectiveness of the proposed method, underscoring its potential as a rapid and portable solution for the assessment of whole-grain foods.

Quantification of polystyrene microplastics in water, milk, and coffee using thermogravimetry coupled with Fourier transform infrared spectroscopy (TGA-FTIR)

Rapid quantification of plastic contaminants, particularly microplastics (MPs), in foods is a challenge. This study introduces a novel method using Fourier transform infrared spectroscopy coupled with thermogravimetric (TGA-FTIR) and chemometric analysis for the quantification of MPs in foods. A model study was performed using polystyrene (PS) MPs (1 μm) added to various foods, namely, water, milk, and coffee without any pretreatment. Foods were spiked with PS microbeads at different concentrations, heated in a TGA, and FTIR spectra of the gases evolved from the TGA were collected over time. The FTIR spectral data were used to construct a Gram-Schmidt profile and identify the characteristic PS peak. The spectrum corresponding to the peak maxima was extracted to represent the specific PS concentration. A dataset of selected spectra and their associated PS concentrations was preprocessed prior to calibration and cross-validation using PLS regression models, for each food matrix studied. The results showed that the PLS models reliably predicted the PS content in water, milk, and coffee with R2CV above 0.96, and RMSECV between 0.045 and 0.07 mg. Multivariate detection limit intervals (LODmin/LODmax) were 0.041/0.085 mg for water, 0.061/0.128 mg for milk and 0.06/0.101 mg for coffee. This method is simple to operate, relatively rapid, and most importantly, does not require sample pretreatment. This research also suggests that the analysis is applicable to a broad range of food samples, and it is suitable for quantifying MPs and nanoplastics regardless of size and shape. The chemometric approach also shows its potential for automation in daily detection and quantification of MPs in food safety control.

Nanopore-assisted ELISA for ultrasensitive, portable, and on-site detection of ricin

Effective detection technologies in food safety with the merits of portable and on-site detection potential are always in pressing demand. Herein, we developed a nanopore-assisted Enzyme-linked immunosorbent assay (NELISA) platform, which innovatively introduced hairpin DNA (HP DNA) probes as reaction substrates. This innovation of substrates effectively avoided the inherent limitations of colorimetric signals (i.e., low sensitivity and inaccurate results) and greatly improved the sensitivity and accuracy of NELISA platform. The alkaline phosphatase (ALP)-modified detection antibody (ALP-Ab2) can specifically bind to ricin and hydrolyze the phosphate groups modified on the HP DNA probes. Nanopore recordings demonstrated that two states of probes produced highly distinguishable nanopore events, enabling the qualitative and quantitative detection of ricin. This NELISA platform fully combined the specificity of ELISA with the ultra-sensitivity, and unique single-molecule fingerprint recognition of nanopore, showing a great on-site detection potential. This method achieved the ultrasensitive and reliable detection of ricin down to 2.46 fg/mL, which enhanced the detection sensitivity by at least 106-fold compared to traditional ELISA. Furthermore, the proposed method was capable of accurately detecting ricin in real food samples with satisfactory recoveries.

A cotton swab platform for fluorescent detection of aluminum ion in food samples based on aggregation-induced emission of carbon dots.

A novel portable cotton swab based on nitrogen-doped carbon dots (NCDs) for Al3+ detection was constructed for the first time. NCDs with bright green fluorescence were prepared by hydrothermal method with phenylhydrazine hydrochloride and 3-hydroxy-2-naphthoic acid hydrazide as precursors. The surface of NCDs was exposed to abundant functional groups (such as amino, carboxyl, hydroxyl, etc.), which was helpful for the formation of complexes between NCDs and Al3+. In the presence of Al3+, the aggregation of NCDs obviously induced their fluorescence enhancement due to the aggregation-induced emission (AIE) of NCDs. Furthermore, the quantum yield (QY) of NCDs was enhanced by 12 times with Al3+, and the fluorescence lifetime was increased by 7.54ns. The fluorescence intensity was linearly correlated with the concentration of Al3+ (2.5-300μM), and the limit of detection was 0.76μM. Moreover, for the portable way, cotton swabs were successfully employed to construct the sensors for the detection of Al3+ in food samples. This proposal haspotential for the application in food analysis.

Probe-based dual-chip digital loop-mediated isothermal amplification for the simultaneous detection of Staphylococcus aureus and Salmonella enteritidis in livestock and aquatic products

Staphylococcus aureus and Salmonella are common pathogens causing foodborne diseases, posing a serious threat to food safety. Accurate detection of foodborne pathogens is particularly critical. This study developed a probe-based dual-chip digital loop-mediated isothermal amplification (cdLAMP) technique that enables the simultaneous detection of Staphylococcus aureus and Salmonella in food samples. The chip contains 20,000 wells, each with a micro-reaction unit volume of approximately 1 nL. The dual-detection is achieved through the dual-color fluorescence channel equipped on the imaging analyzer. Compared with qPCR, the cdLAMP demonstrates superior sensitivity. In the detection of pure cultures and spiked food samples, the detection limit of two foodborne pathogens is 2 CFU/mL. In the detection of field samples, it is capable of detecting single colonies of both pathogens. The dynamic detection range spans 5 logs. In conclusion, the probe-based cdLAMP technique emerges as a user-friendly tool for detecting foodborne pathogens, providing a powerful platform for food safety testing.

The effectiveness of information, education, and communication (IEC) methods on food safety and hygiene among food vendors during Ramadan

Background: During Ramadan 2023, only 4.7% of the 104 snack and food outlets in Jakarta, Indonesia, at the Cilandak District Primary Health Center met hygiene and sanitation standards. The inspections involved supervising cleanliness, implementing HACCP (Hazard Analysis & Critical Control Point), and counseling on the implementation of health and food safety practices. Purpose: To evaluate the impact of information, education, and communication (IEC) methods on food safety and hygiene practices among street food vendors during Ramadan. Method: A quantitative design with a quasi-experimental approach, an information, education, and communication (IEC) methods on food safety and hygiene for food vendors during the month of Ramadan consisting of one group. The study had two steps: first, it inspected food outlets before and after an educational intervention using a health environment inspection (eIKL PaJan) form; secondly, it tested food samples using a rapid test. Three outlets were randomly selected from each of the five sub-districts, and the data was analyzed using a paired T-test. The level of statistical significance was set at an alpha level of 0.05. Results: Fifteen "takjil" snack vendors were evaluated, and most had non-conformity scores. The highest non-conformity scores were due to hand hygiene issues and lack of knowledge about food safety. After the intervention, the mean score of knowledge about safe food handling increased from 57.5 to 75.9, with p<0.001 indicating an increase in awareness of food safety perceptions. Of the fifteen food samples tested, six showed the presence of formalin in the rapid test. However, subsequent testing at the laboratory revealed that the samples were free of formalin. Conclusion: Our study highlights a significant public health concern: enhancing awareness can bolster the safety, cleanliness, and knowledge of snack food outlet proprietors. This could positively affect the economy, human resource quality, and health through the implementation of food security practices.

Antibacterial activity of lactic acid bacteria isolated from traditionally fermented food against food pathogen

Aim: To evaluate the antibacterial activity of lactic acid bacteria against selected food pathogens (Escherichia coli and Staphylococcus aureus). Method: A total of twenty (20) traditionally fermented food samples were purchased from a market in Owerri metropolis. Isolation and identification of lactic acid bacteria (LAB) were conducted using standard microbiological techniques. LAB was identified using standard morphological and biochemical tests. They were tested against food pathogens using the Agar well diffusion method. Results: The isolated lactic acid bacteria include Lactobacillus fermentum, Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum and were label as SP1, SP2, SP3, and SP4 respectively. The isolated LAB species had a considerable inhibitory effect on food borne pathogens. Cell free supernatant of four species were tested for antagonistic activity at 24hrs and 48hrs incubation time. Cell free supernatant from 48hrs broth of SP1 showed the highest zone of inhibition on Escherichia coli (28mm) while the cell free supernatant from 24hrs broth of SP4 showed the lowest zone of inhibition on Staphylococcus aureus (13 mm). Conclusion: The antimicrobial activity increases with time. LAB demonstrated high antimicrobial properties against food borne pathogens. This potential can be employed as starters in food industry to inhibit food spoilage microbes and contaminants.

Comparison of Different Solid-Phase Microextraction Formats Dedicated to the Analysis of Volatile Compounds-A Comprehensive Study.

The coupling of Solid-Phase Microextraction (SPME) technology with gas chromatography (GC) has a well-established and successful history. Traditionally, SPME fibers have been the most popular form thanks to their versatility and the ease with which they can be fully automated. However, alternative geometries for SPME have been developed over the years, beginning with Stir Bar Sorptive Extraction (SBSE) and later evolving into Thin-Film SPME (TF-SPME) devices. Each of these formats offers distinct advantages and disadvantages, which are explored in this study. The primary objective of this study was to comprehensively compare available forms of SPME devices, with a special focus on the advantages of TF-SPME, a novel microextraction method particularly suited for the analysis of odorants in food. The study involved analyzing a standard mixture of 11 key food odorants, representing a range of polarities, to evaluate the efficiency of TF-SPME devices in terms of the number of analytes extracted. Furthermore, four types of TF-SPME devices were compared against each other in both standard mixtures and actual food samples. The final stage of the study employed GCxGC-ToFMS analysis to showcase the potential of the most efficient HLB-TF-SPME device in the non-targeted analysis of complex samples, exemplified by unfiltered wheat beer. This analysis demonstrated the significant capability of HLB-TF-SPME in capturing and identifying a wide range of volatile compounds in complex matrices.

Monitoring of Bacillus spore-forming dynamics through flow cytometry.

The plate counting method is a traditional and widely accepted technique for live cell counting, often employed for Bacillus enumeration and spore forming rate calculations. However, this method requires at least 12 h to generate results, making it unsuitable for real-time monitoring of bacterial growth status and spore transformation rate. Bacillus thuringiensis crystals, produced during sporulation, are widely used as microbial pesticides, with high demand for industrial scale production. Variations in cultivation conditions and harvest timing during large-scale pore production of Bacillus thuringiensis significantly affect spore forming rate, impacting crystallization yield. Nevertheless, there is a lack of real-time monitoring methods for spore conversion rate. Flow cytometry (FCM), a well-established technique for single-cell analysis in eukaryotic cells, has been successfully applied in bacterial detection in environmental and food samples. In this study, we introduced a rapid flow cytometry-based method for determining spore forming rate of Bacillus thuringiensis, with two nucleic acid dyes, SYTO24 and LDS751. The method enables dynamic monitoring of spore, vegetative cell, and viable but non-culturable/dead cell proportions during the whole cultivation process, and spore forming rate could be gained within 30 min. Data of spore forming rate by FCM method is consistent with that by plate counting method, offering a faster and more efficient approach for assessing sporulation status in industrial Bacillus thuringiensis microbial pesticide production.

Fabrication of a high-sensitivity electrochemical immunosensor by the oriented immobilization of engineered nanobody on nanofibrous membrane.

Anew type of label-free electrochemical immunosensor for the high-sensitivity determination of parathion was developed based on the oriented immobilization of nanobody (VHH9) on agold nanoparticle-loaded polyvinyl alcohol/citric acid nanofiber membrane-modified electrode. The morphology characterization and assembly process of the modified materials were investigated using scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Under the optimum conditions, the label-free electrochemical immunosensor for parathion exhibited a linear range of 0.0015-6400ng/mL and a low detection limit of 0.48pg/mL, the signal response of which was 10 times higher than that of the randomly immobilized VHH9. The immunosensor possessed high selectivity, good repeatability and reusability (keeping above 90% of its initial activity after repeating 8 times), and stability (remaining 90% after 9weeks of storage). Finally, the average recoveries of parathion from food samples were 93.76-105.73% with the coefficient of variation being 2.65-6.85%, showing good correlation with UPLC (R2 = 0.9950). Therefore, our nanobody immobilization protocol is simple and effective and proves the potential to be utilized as a promising candidate for sensing platform.

A Novel Approach for Colorimetric Detection of Glyphosate in Food Based on a Split Aptamer Nanostructure and DNAzyme Activity.

Glyphosate has become the most widely used herbicide worldwide in recent years. There are many concerns about toxicity and mutagenicity from long-term use of glyphosate in humans and animals. Therefore, the methods that can help in easy and quick detection of this chemical compound in food and water are critical. In this work, a biosensor was fabricated by combining the enzymatic properties of a specific DNA G-quadruplex and selectivity of a split aptamer to detect glyphosate in foods and water in a quick and simple colorimetric manner. The color change in this method is based on the oxidation of TMB by the G-quadruplex enzyme and the function of aptamer to trap glyphosate, which is visible to the naked eye in the presence and absence of the herbicide. The biosensor showed its high performance in various real samples of water and foods and provided a detection limit of 1.37 nM (R² = 0.9899) with a linear response range of 100 to 400 nM of glyphosate. This biosensor can provide an innovative, cheap and fast approach for the detection and monitoring of glyphosate in various foods and water.

Occurrence and diversity of Campylobacter species in diarrheic children and their exposure environments in Ethiopia

Campylobacter is a major zoonotic foodborne pathogen that poses a significant public health threat, particularly among children and immunocompromised individuals. However, data on the occurrence and sources of Campylobacter infection remain scarce in Ethiopia. This study assessed the occurrence, diversity, and relationships between Campylobacter from diarrheic children and potential exposure sources using whole-genome sequencing. Through case-based tracing, animal, food, and environmental samples were collected from Harar town and Kersa district between November 2021 and January 2023. Campylobacter was identified using selective media, and DNA was extracted and sequenced with the Illumina NextSeq 550 instrument. Sequence reads were analysed using bioinformatics tools. The overall Campylobacter prevalence in the exposure sources was 5.5%, with 6.0% in urban and 5.0% in rural settings. Campylobacter detection was 1.8 times more likely in household samples (8.7%; OR = 1.8; 95% CI: 0.7–4.5) than in samples from marketplaces. The occurrence of Campylobacter in food was 4.2%, with no significant differences across the meat, milk, and other food categories. The likelihood of Campylobacter contamination in the environment was 5.8 times higher in the presence of poultry (17.7%; OR = 5.8; CI: 1.1–30.6) compared to shoats. Sequence analysis identified a low Campylobacter spp. diversity comprising only C. jejuni and C. coli, which were characterized by 8 distinct sequence types (STs). Phylogenetically, the majority of the sequenced case isolates were clustered with isolates from either caretakers, environmental exposures, or both. In conclusion, Campylobacter was detected in various exposure sources of diarrheic children, and its occurrence did not differ significantly between Kersa and Harar or among food items. The majority of isolates shared MLST profiles and clustered together, demonstrating the involvement of multiple vectors in the transmission of the pathogen. Genome-based integrated studies supported by an attribution model are recommended to determine the relative contribution of each source.

Selection and immobilization of the optimal phytase-producing probiotic: a comparative in silico analyses of five autochthonous lactic acid bacteria

Phytic acid and its salts are the major storage form of both phosphate and myo-inositol, especially in cereals. Phytic acid chelates multivalent cations, which decreases the solubilized form of these nutrients and their dietary bioavailability for absorption and assimilation. Increasing micronutrient bioavailability from the economic phytate-rich food can be achieved by subjecting this food to fermentation by phytase-producing bacteria. A total of 8 lactic acid bacteria were isolated from different fermented food samples. Among the bacteria tested for their ability to produce phytase, only five isolates were selected as promising producers. The results revealed that isolate No. 4 produced the highest phytase levels of 411 U/mL. The five isolates were differentially able to tolerate acidic, alkaline, heat, surfactant, osmotic, bile, and pancreatic enzyme stresses, with the superiority of isolate No. 4, which demonstrated the most desirable probiotic potentials as confirmed by principal component analysis (PCA), heat map, and network analysis. Isolate No. 4 was identified by 16S rRNA sequencing and later confirmed as Pediococcus pentosaceus strain NMP4762Ch under the accession number MZ413646. Moreover, the active cells of P. pentosaceus were immobilized in alginate; the reusability of the immobilized active cells resulted in continuous production with an optimum phytase activity of 432.0 U/mL after 14 days, which decreased with time to reach 142.5 U/mL after 56 days. The maximum shelf stability was also observed, 557.5 U/mL, after 14 days and declined with time, reaching 133.5 U/mL by the end of the 56th day. Since humans don’t naturally produce phytase, utilizing probiotics for phytase production is important to combat mineral deficiencies.

The 1H HR-NMR Methods for the Evaluation of the Stability, Quality, Authenticity, and Shelf Life of Foods

1H High-Resolution Nuclear Magnetic Resonance (1H HR-NMR) spectroscopy is a powerful analytical methodology used in various fields, including food science. In the food science field, NMR combined with the principles of metabolomics can provide detailed information about a food’s molecular composition, structure, dynamics, and interactions within food matrices, making it invaluable for assessing changes during storage, processing, and shelf life. This entry aims to list the main applications of one-dimensional 1H HR-NMR methods in the field of food science, such as their use in the assessment of the stability, quality, authenticity, and shelf life of food samples. Several kinds of foods are taken into consideration to give a huge overview of the potentiality of the methods.

Validation of the Peel Plate Staphylococcus Aureus (SA) Test for Enumeration of S. aureus in Selected Foods and Non-cultured Dairy Products: AOAC Performance Tested MethodSM 082401.

The microbial testing platform, Peel Plate™, was developed with Baird Parker ingredients for Staphylococcus aureus (SA) specificity. After rehydrating with 1 mL of the diluted food sample, Peel Plate SA is incubated for 24-48 h at 35-37 °C and observed for purple colonies. A validation study was performed to evaluate Peel Plate SA for enumeration of S. aureus in selected foods and non-cultured dairy products for Performance Tested MethodsSM (PTM) certification. Peel Plate SA was evaluated in inclusivity/exclusivity and matrix studies, product consistency, stability, and robustness testing. Non-fat dried milk, frozen raw cod fish, corned beef, frozen raw vegetables, potato salad, vegetable soup, frozen unshelled raw shrimp and baby food (apple, cinnamon, and granola) were evaluated in the matrix studies comparing Peel Plate SA to U.S. and international reference methods. Three levels of contamination along with non-inoculated controls were tested for each matrix. Peel Plate SA detected 49 of 50 S. aureus isolates tested. Of the 38 exclusivity species tested, none were detected. In the matrix studies, the Peel Plate SA results were determined to be equivalent to the reference method results by paired statistical analysis. In an accelerated stability study, the shelf-life of Peel Plate SA was shown to be stable for 12 months. Equivalence was demonstrated between different production lots. Small changes to critical test parameters did not significantly affect the Peel Plate SA results. Peel Plate SA is a ready-to-use method for enumeration of S. aureus in a variety of foods and non-cultured dairy products. As with reference methods, colonies Peel Plate SA colonies should be isolated and confirmed with differentiation tests such as catalase and strong coagulase positive. The data were reviewed by the PTM Program and certification was granted for the Peel Plate SA method PTM 082401.

Measuring palatability of pet food products: Sensory components, evaluations, challenges, and opportunities.

The pet food industry is a growing business launching a variety of new products in the market. The acceptability or preference of pet food samples has traditionally been measured using either one-bowl or two-bowl tests. Academic researchers and professionals in the pet food industry have explored other methods, including the cognitive palatability assessment protocols and the ranking test, to evaluate more than two samples. A variety of approaches and perspectives were also utilized to predict palatability and key sensory attributes of pet foods, including descriptive sensory analysis by human-trained panelists and pet food caregivers' perceptions of pet food. This review article examined a range of testing methods for evaluating the palatability of pet foods, specifically targeting products for dogs and/or cats. It outlined the advantages and disadvantages of each method. Additionally, the review provided in-depth insights into the key sensory attributes of pet foods and the methodologies for assessing palatability. It also explored pets' behavioral responses and facial expressions in relation to different pet foods. Furthermore, this review discussed current challenges and future opportunities in pet food development, including the use of instrumental analyses and artificial intelligence-based approaches.