Authenticity Testing Research Articles

Rapid analysis of meat floss origin using a supervised machine learning-based electronic nose towards food authentication

Authentication of meat floss origin has been highly critical for its consumers due to existing potential risks of having allergic diseases or religion perspective related to pork-containing foods. Herein, we developed and assessed a compact portable electronic nose (e-nose) comprising gas sensor array and supervised machine learning with a window time slicing method to sniff and to classify different meat floss products. We evaluated four different supervised learning methods for data classification (i.e., linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), k-nearest neighbors (k-NN), and random forest (RF)). Among them, an LDA model equipped with five-window-extracted feature yielded the highest accuracy values of >99% for both validation and testing data in discriminating beef, chicken, and pork flosses. The obtained e-nose results were correlated and confirmed with the spectral data from Fourier-transform infrared (FTIR) spectroscopy and gas chromatography–mass spectrometry (GC-MS) measurements. We found that beef and chicken had similar compound groups (i.e., hydrocarbons and alcohol). Meanwhile, aldehyde compounds (e.g., dodecanal and 9-octadecanal) were found to be dominant in pork products. Based on its performance evaluation, the developed e-nose system shows promising results in food authenticity testing, which paves the way for ubiquitously detecting deception and food fraud attempts.

Isotope Fingerprinting as a Backup for Modern Safety and Traceability Systems in the Animal-Derived Food Chain.

In recent years, due to the globalization of food trade and certified agro-food products, the authenticity and traceability of food have received increasing attention. As a result, opportunities for fraudulent practices arise, highlighting the need to protect consumers from economic and health damages. In this regard, specific analytical techniques have been optimized and implemented to support the integrity of the food chain, such as those targeting different isotopes and their ratios. This review article explores the scientific progress of the last decade in the study of the isotopic identity card of food of animal origin, provides the reader with an overview of its application, and focuses on whether the combination of isotopes with other markers increases confidence and robustness in food authenticity testing. To this purpose, a total of 135 studies analyzing fish and seafood, meat, eggs, milk, and dairy products, and aiming to examine the relation between isotopic ratios and the geographical provenance, feeding regime, production method, and seasonality were reviewed. Current trends and major research achievements in the field were discussed and commented on in detail, pointing out advantages and drawbacks typically associated with this analytical approach and arguing future improvements and changes that need to be made to recognize it as a standard and validated method for fraud mitigation and safety control in the sector of food of animal origin.

Clustering of Tadalafil API Samples According to their Manufacturer in the Context of API Falsification Detection

This paper reports the results of the active pharmaceutical ingredient (API) fingerprint study, organised by the General European Official Medicines Control Laboratory Network (GEON), on tadalafil. A classical market surveillance study, evaluating compliance to the European Pharmacopoeia, was combined with a fingerprint study, the latter to obtain characteristic data for the different manufacturers, allowing the network laboratories to conduct authenticity tests for future samples, as well as to detect substandard and falsified samples.In total, 46 tadalafil API samples from 13 different manufacturers were collected. For all samples fingerprint data was collected through analysis of impurities and residual solvents, mass spectrometric screening, X-ray powder diffraction and proton nuclear magnetic resonance (1H-NMR). Chemometric analysis revealed that all manufacturers could be characterised based on the impurity, residual solvent and 1H-NMR data. Future suspicious samples in the network will therefore be analysed with these techniques in order to attribute the sample to one of the manufacturers. If the sample cannot be attributed, a more profound investigation will be necessary to reveal the origin of the sample. In cases where the suspect sample is claimed to be from one of the manufacturers included in this study, analysis can be limited to the test distinguishing that manufacturer.

Identification of sunflower, rapeseed, flaxseed and sesame seed oil metabolomic markers as a potential tool for oil authentication and detecting adulterations.

Testing the composition, quality and authenticity of edible oils is crucial to safeguard the consumers' rights and health. The aim of our study was to identify oil-specific markers to enable the differentiation and authentication of sunflower, sesame, flaxseed and rapeseed oils, and to evaluate their antioxidant activity, total phenolic and carotenoid content. A metabolomic approach based on liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry was employed for marker discovery. Spectrophotometric method was used for determination of antioxidant activity, total phenolic and carotenoid content. 76 oil samples from the four different manufacturers were examined. We identified 13 oil-specific markers for sunflower seed oil, 8 for rapeseed oil, 5 for sesame seed oil and 3 for flaxseed oil, their retention times, accurate masses, and characteristic fragment ions are reported. The abundances of the markers for each plant species were found to vary depending on the oil producer and the product batch. Significant differences in antioxidant activity, total phenolic and carotenoid content were also observed both between oils and within oil type. The highest total phenolic content (84.03 ± 4.19 to 103.79 ± 3.67 mg of gallic acid/kg) and antioxidant activity (245.67 ± 7.59 to 297.22 ± 2.32 mg Trolox/kg) were found in sesame seed and flaxseed oils, respectively. Identified metabolic markers can be used as qualitative markers to confirm the authenticity or to detect adulterations of oils. Composition, properties and authenticity testing should be more rigorous for food products marketed as health-promoting.

A systematic review of DNA-based methods in authentication of game and less common meat species.

Despite the numerous studies on food safety and authenticity, especially for meat and meat products, not enough studies have been conducted focusing exclusively on game species and other unusual meat animals. As a result of the European horse scandal, the horse is currently the target of many meat authenticity studies. With this review, we aim to present various DNA-based methods that have been used by researchers to identify, detect, and quantify game, uncommon meat animals, and wildlife species. Polymerase chain reaction (PCR) is considered the standard method for DNA analysis in meat authenticity testing. However, in this paper, we present several other methods that may or may not involve the PCR technique. For this purpose, we systematically reviewed 131 articles selected according to various criteria such as target animal species, method of analysis, year of publication, and so forth. The result of our study shows the most studied game and uncommon meat species, PCR- and non-PCR-based methods for game meat analysis, and DNA-based methods in wildlife conservation. With this study, researchers can find detailed information about frequent game species used as adulterants for regular meat products and the DNA-based techniques to identify them.

Discovery and Optimization of Neutralizing SARS-CoV-2 Antibodies Using ALTHEA Gold Plus Libraries™.

We recently reported the isolation and characterization of anti-SARS-CoV-2 antibodies from a phage display library built with the VH repertoire of a convalescent COVID-19 patient, paired with four naïve synthetic VL libraries. One of the antibodies, called IgG-A7, neutralized the Wuhan, Delta (B.1.617.2) and Omicron (B.1.1.529) strains in authentic neutralization tests (PRNT). It also protected 100% transgenic mice expressing the human angiotensin-converting enzyme 2 (hACE-2) from SARS-CoV-2 infection. In this study, the four synthetic VL libraries were combined with the semi-synthetic VH repertoire of ALTHEA Gold Libraries™ to generate a set of fully naïve, general-purpose, libraries called ALTHEA Gold Plus Libraries™. Three out of 24 specific clones for the RBD isolated from the libraries, with affinity in the low nanomolar range and sub-optimal in vitro neutralization in PRNT, were affinity optimized via a method called "Rapid Affinity Maturation" (RAM). The final molecules reached sub-nanomolar neutralization potency, slightly superior to IgG-A7, while the developability profile over the parental molecules was improved. These results demonstrate that general-purpose libraries are a valuable source of potent neutralizing antibodies. Importantly, since general-purpose libraries are "ready-to-use", it could expedite isolation of antibodies for rapidly evolving viruses such as SARS-CoV-2.

Test-taking strategy use by Chinese young EFL learners in an authentic international standardized English test

The current study examined language test-taking strategies used by Chinese young learners of English as a foreign language (EFLs) in an authentic international standardized English test–Cambridge Young Learners English Test: Flyers Test. It adopted a mixed-methods approach: the quantitative part was a survey administered to 138 participants, and the qualitative part consisted of think-aloud sessions and retrospective interviews with six participants (three were high-achievers and three were low-achievers). The quantitative results show that in general, children adopted metacognitive test-taking strategies more frequently than cognitive test-taking strategies irrespective of language skills; and the high-achievers used test-taking strategies more frequently than their low-achievers. The two-way interaction effects between levels of test performance ☓ strategy type and between language skills ☓ strategy type were also significant. The qualitative results demonstrate that the high-achievers not only used a broader range of cognitive strategies than low-achievers, they also used the same metacognitive strategies at an in-depth level and in a more sophisticated way than low-achievers. The results of the study suggest that expanding Chinese young EFL learners’ repertoire of test-taking strategies and modeling desirable ways of using strategies may help them improve their test-taking strategy use.

Family capital, social stratification, and access to higher education: An empirical study in mainland China.

This paper employs Bourdieu's theory of capital-focusing on family cultural, social, and economic capital-to research the early-stage mechanism through which access to higher education is formed. While all three types of capital play a significant role in acquiring higher education, most studies tend to focus on just one type of capital. In recent years, domestic scholars have also analyzed in detail the family factors affecting children's access to higher education (CAHE); however, they have not yet explained the mechanism by which these factors influence CAHE, and authentic tests are rare. Therefore, based on existing research, this paper uses the theoretical concept of family capital to reveal how contemporary Chinese families affect their CAHE. This paper analyzes the relationship between family capital, social stratification, and access to higher education opportunities using an econometric model based on baseline data from the China Family Panel Studies (CFPS) from 2010 to 2020, with 10,318 participants, including 4,419 females and 5,899 males. The results of a binary logistic regression analysis show that the possession of family cultural and economic capital has a direct positive influence on CAHE. Children from the elite stratum often benefit more from the accumulation of family cultural capital. Moreover, although it does not form a distinct stratum, the possession of family social capital also significantly influences children's access to higher education. Driven by China's political, economic, and social environment, some children from the blue-collar stratum have a comparative advantage in terms of access to higher education. The possession of family capital is an important factor in the stratification of CAHE, and cultural capital is the most influential type of capital. Parents with a low level of education should be encouraged to become engaged in schools and communities to take professional courses in assisted learning, emotional counseling, decision-making, and voluntary service.

Toward the Non-Targeted Detection of Adulterated Virgin Olive Oil with Edible Oils via FTIR Spectroscopy & Chemometrics: Research Methodology Trends, Gaps and Future Perspectives.

Fourier-Transform mid-infrared (FTIR) spectroscopy offers a strong candidate screening tool for rapid, non-destructive and early detection of unauthorized virgin olive oil blends with other edible oils. Potential applications to the official anti-fraud control are supported by dozens of research articles with a "proof-of-concept" study approach through different chemometric workflows for comprehensive spectral analysis. It may also assist non-targeted authenticity testing, an emerging goal for modern food fraud inspection systems. Hence, FTIR-based methods need to be standardized and validated to be accepted by the olive industry and official regulators. Thus far, several literature reviews evaluated the competence of FTIR standalone or compared with other vibrational techniques only in view of the chemometric methodology, regardless of the inherent characteristics of the product spectra or the application scope. Regarding authenticity testing, every step of the methodology workflow, and not only the post-acquisition steps, need thorough validation. In this context, the present review investigates the progress in the research methodology on FTIR-based detection of virgin olive oil adulteration over a period of more than 25 years with the aim to capture the trends, identify gaps or misuses in the existing literature and highlight intriguing topics for future studies. An extensive search in Scopus, Web of Science and Google Scholar, combined with bibliometric analysis, helped to extract qualitative and quantitative information from publication sources. Our findings verified that intercomparison of literature results is often impossible; sampling design, FTIR spectral acquisition and performance evaluation are critical methodological issues that need more specific guidance and criteria for application to product authenticity testing.

The Development of an Authentic Technology-Based Test for Measuring Economic Competence

The Development of an Authentic Technology-Based Test for Measuring Economic Competence

Morphological, Physiological and Biohchemical Identification of Nitrogen Fixing Mesorhizobium in Chickpea

Chickpea is the world’s second most important legume, and it can be nodulated with a variety of rhizobial species to generate root nodules. The current study investigated the isolation, cultural, and biochemical characterization of several strains of root nodulating bacteria from different locations of Yavatmal districts. The serial dilution approach was used for isolation. Bacterium Mesorhizobium is a gram- negative, aerobic, non-spore producing, motile rods with circular, convex, whitish pink, and glistering colonies with an entire edge. The biochemical characterization of five different strains of bacteria revealed that the catalase, methyl red, urease, and triple sugar iron and citrate utilization test yielded positive results. Based on morphological, biochemical, and physiological characters most of the characteristics were found like the Mesorhizobium spp. The physical and biochemical properties of five different isolates of bacteria were analyzed to determine their taxonomic position, and the authentication test revealed that the strain of rhizobium bacteria is Mesorhizobium spp.

Development of Non-Targeted Mass Spectrometry Method for Distinguishing Spelt and Wheat.

Food fraud, even when not in the news, is ubiquitous and demands the development of innovative strategies to combat it. A new non-targeted method (NTM) for distinguishing spelt and wheat is described, which aids in food fraud detection and authenticity testing. A highly resolved fingerprint in the form of spectra is obtained for several cultivars of spelt and wheat using liquid chromatography coupled high-resolution mass spectrometry (LC-HRMS). Convolutional neural network (CNN) models are built using a nested cross validation (NCV) approach by appropriately training them using a calibration set comprising duplicate measurements of eleven cultivars of wheat and spelt, each. The results reveal that the CNNs automatically learn patterns and representations to best discriminate tested samples into spelt or wheat. This is further investigated using an external validation set comprising artificially mixed spectra, samples for processed goods (spelt bread and flour), eleven untypical spelt, and six old wheat cultivars. These cultivars were not part of model building. We introduce a metric called the D score to quantitatively evaluate and compare the classification decisions. Our results demonstrate that NTMs based on NCV and CNNs trained using appropriately chosen spectral data can be reliable enough to be used on a wider range of cultivars and their mixes.

DNA barcoding seafood products for export from the Philippines

Accurate and responsible identification and labeling as a precautionary measure to ensure health safety and sustainability in fish and fishery products consumption is an issue that is taken seriously in global trade operations. In the Philippines, the Consumer Act (Republic Act 7394) mandates that all products should be properly labeled as to its accurate nature, quality and quantity. More innovative and reliable way to assess species identity and authenticity testing in commercial fishery export products in the country is needed. A survey of the export fishery products was conducted to assess whether the species indicated on the labels is correct using DNA barcoding. Tissue samples belonging to different product categories were collected from registered and accredited exporting companies from Metro Manila, Metro Cebu, General Santos City and Palawan. A total of 189 samples was sequenced and identified. Eighty six (86) or 45.50% were accurately labeled, eighty eight (88) or 45.56% were partially labeled and fifteen (15) or 7.94% were mislabeled. Mislabeled products were found to occur in Metro Manila (7 or 3.70%), in Metro Cebu (1 or 0.53%) and General Santos City (7 or 3.70%). Forty five (45) samples out of the 189 or 23.81% identified were from prepared and preserved, and cured. This study showed that DNA barcoding can identify products even those that have undergone processing and preservation, and that it is an effective tool in the detection of seafood mislabeling, which can be used for traceability and regulatory activities of government agencies to monitor seafood trade.

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

Creating Secure File Systems in Open-Source Operating Systems

The relevance of this study is determined by insecure data storage on personal computers, as it is the main operating system that performs authentication and file access control. Bypassing these security rules is possible in case of using another open-source operating system on the same personal computer. The aim of this work is the research and development of file encryptors, disk encryptors and file system encryptors. Each of them has its shortcomings which manifest themselves during development. Combining the advantages of file encryptors and file system encryptors helped to overcome those shortcomings. The userspace filesystem library was used for this purpose. The study involved the methods aimed at designing and developing the Udev daemon file system for Linux using the OpenSSL library. The file system design was mathematically modelled and formally verified through a test parser. The file system also has its own authentication and authorization procedures to provide uniform access across multiple operating systems. The Udev daemon file system is the result of this work. Each file is encrypted with a separate key to protect against cryptanalysis. This key is encrypted with the owner’s private key, thereby enabling him/her to change the ownership. The passphrase is used to decrypt the user’s private key. The developed file system has passed authentication and access control testing successfully. The file system shows best performance with file sizes 1 KB to 256 MB. Encryption-caused performance degradation was also measured and found to be within acceptable limits. This Udev daemon stackable file system is available for all Unix clones with OpenSSL libraries. The prospects for further work are the development of a file system using several combined methods from a list of existing design and development methods for file systems.

Pork liver tissue-specific peptide markers for food authenticity testing and adulteration detections

A liquid chromatography-mass spectrometry bottom-up proteomic approach was applied for the detection and identification of proteins from liver tissues. We identified 74 unique pork liver peptide markers that are resistant to the thermal processing of food. These peptides are derived from 43 proteins, which perform various functions in the liver. Roasted and sterilised pâté-type products with a pork liver content ranging from 6% to 51% were examined to select the most reliable pork liver peptide markers that survive unmodified in complex processed food matrices. Of the 74 specific heat-stable peptides detected in pure liver tissue, five (GDAPEEEVSLSK, ALTAELEAVGK, TFYLNVLNEEER, AQFGQPEILLGTIPGTGGTQR and VIAPGFNALEQILQSTAGK) were the best candidates to confirm the presence of liver tissue in highly processed meat products. We have identified unique tissue-specific markers that enable rapid and specific identification of pork liver in processed food and may contribute to the development of new methods for testing food authenticity.

How to Design a Relatively Authentic Language Test?

How to Design a Relatively Authentic Language Test?

Impact of genus (Geotrigona, Melipona, Scaptotrigona) on the targeted 1H-NMR organic profile, and authenticity test by interphase emulsion of honey processed in cerumen pots by stingless bees in Ecuador

The biodiversity of Ecuadorian stingless bees is almost 200 species. Traditional pot-honey harvest in Ecuador is mostly done from nests of the three genera selected here Geotrigona Moure, 1943, Melipona Illiger, 1806, and Scaptotrigona Moure, 1942. The 20 pot-honey samples collected from cerumen pots and three ethnic honeys “abeja de tierra”, “bermejo”, and “cushillomishki” were analyzed for qualitative and quantitative targeted 1H-NMR honey profiling, and for the Honey Authenticity Test by Interphase Emulsion (HATIE). Extensive data of targeted organic compounds (41 parameters) were identified, quantified, and described. The three honey types were compared by ANOVA. Amino acids, ethanol, hydroxymethylfurfural, aliphatic organic acids, sugars, and markers of botanical origin. The number of phases observed with the HATIE were one in Scaptotrigona and three in Geotrigona and Melipona honeys. Acetic acid (19.60 ± 1.45 g/kg) and lactic acid (24.30 ± 1.65 g/kg) were particularly high in Geotrigona honey (in contrast to 1.3 g/kg acetic acid and 1.6 g/kg lactic acid in Melipona and Scaptotrigona), and with the lowest fructose + glucose (18.39 ± 1.68) g/100g honey compared to Melipona (52.87 ± 1.75) and Scaptotrigona (52.17 ± 0.60). Three local honeys were tested using PCA (Principal Component Analysis), two were assigned with a correct declared bee origin, but “bermejo” was not a Melipona and grouped with the Scaptotrigona cluster. However after HCA (Hierarchical Cluster Analysis) the three honeys were positioned in the Melipona-Scaptotrigona cluster. This research supports targeted 1H-NMR-based profiling of pot-honey metabolomics approach for multi-parameter visualization of organic compounds, as well as descriptive and pertained multivariate statistics (HCA and PCA) to discriminate the stingless bee genus in a set of Geotrigona, Melipona and Scaptotrigona honey types. The NMR characterization of Ecuadorian honey produced by stingless bees emphasizes the need for regulatory norms. A final note on stingless bee markers in pot-honey metabolites which should be screened for those that may extract phylogenetic signals from nutritional traits of honey. Scaptotrigona vitorum honey revealed biosurfactant activity in the HATIE, originating a fingerprint Honey Biosurfactant Test (HBT) for the genus in this set of pot-honeys.

Online Unproctored Clinical Examinations: The Perceptions and Performance of Final Year Dental Students.

Take home, or open-book, examinations (OBE) are designed to be completed at a location of student choice, whilst providing comprehensive assessment of learning outcomes. Supporters of OBE refer to their authenticity, in that they reflect real-world practice where use of external resources is routine and encouraged. A contrasting view is that efficient practice requires a solid base of knowledge upon which to draw. The aim of this evaluation was to elicit learners' perceptions of the open-book, unproctored examination approach; we sought student views on authenticity, assessment preparation, use of resources, and anxiety. Quantitative and qualitative data were gathered using an online, self-administered survey. We sought to determine the correlation between student views and examination performance via consideration of final examination marks. Heightened anxiety levels tended to increase assessment preparations and were found to be inversely related to learners' perceptions that the OBE was an authentic test. An inverse relationship was seen between learners' OBE examination performance and consulting resources during the examination. Examination marks were not significantly related to endorsement of continued online delivery of learning, time spent preparing for OBE in comparison to other types of assessment, greater anxiety than usual, perceptions of test authenticity, or experiencing a supportive test environment. The results of this study may inform curriculum and assessment development, learning and teaching practices, and support student voice and experience.