High resolution melting analysis as a new approach to discriminate gluten-containing cereals

Recent advancements in the sensors for food analysis to detect gluten: A mini-review [2019-2023]

People with celiac disease or gluten sensitivity may experience an immune reaction to the protein called gluten, which is present in wheat, barley, and rye. A strict gluten-free diet is the sole cure for these ailments. There are chances of food fraud about the claim of being gluten-free food items. As a result, there is a rising need for trustworthy and precise ways to identify gluten. There are many methods to detect gluten in food samples viz., enzyme-linked immunosorbent assay 1 Surface plasmon resonance (SPR), Electrochemical sensors, Fluorescence-based sensors, etc. The use of sensors is one of the most promising methods for gluten detection. For detecting gluten, a variety of sensors, including optical, electrochemical, and biosensors, have been developed with different limits of detection and sensitivity. The present review reports the recent advancements (2019-2023) in the development of sensors for gluten detection in food. We may conclude that sensitivity and limit of detection are not related to the type of sensor used (aptamer or antibody-based), however, there are advancements, with the year, on the simplicity of the material used like paper-based sensors and paradigm shift to reagent free sensors by the spectral analysis. Also, recent work shows the potential of IoT-based studies for gluten detection.

Using plants in forensics: State-of-the-art and prospects

The increasing use of plant evidence in forensic investigations gave rise to a powerful new discipline - Forensic Botany - that analyses micro- or macroscopic plant materials, such as the totality or fragments of an organ (i.e., leaves, stems, seeds, fruits, roots) and tissue (i.e., pollen grains, spores, fibers, cork) or its chemical composition (i. e., secondary metabolites, isotopes, DNA, starch grains). Forensic botanists frequently use microscopy, chemical analysis, and botanical expertise to identify and interpret evidence crucial to solving civil and criminal issues, collaborating in enforcing laws or regulations, and ensuring public health safeguards. The present work comprehensively examines the current state and future potential of Forensic Botany. The first section conveys the critical steps of plant evidence collection, documentation, and preservation, emphasizing the importance of these initial steps in maintaining the integrity of the items. It explores the different molecular analyses, covering the identification of plant species and varieties or cultivars, and discusses the limitations and challenges of these techniques in forensics. The subsequent section covers the diversity of Forensic Botany approaches, examining how plant evidence exposes food and pharmaceutical frauds, uncovers insufficient or erroneous labeling, traces illegal drug trafficking routes, and combats the illegal collection or trade of protected species and derivatives. National and global security issues, including the implications of biological warfare, bioterrorism, and biocrime are addressed, and a review of the contributions of plant evidence in crime scene investigations is provided, synthesizing a comprehensive overview of the diverse facets of Forensic Botany.

Allergenicity of wheat protein in diet: Mechanisms, modifications and challenges

Wheat is widely available in people's daily diets. However, some people are currently experiencing IgE-mediated allergic reactions to wheat-based foods, which seriously impact their quality of life. Thus, it is imperative to provide comprehensive knowledge and effective methods to reduce the risk of wheat allergy (WA) in food. In the present review, recent advances in WA symptoms, the major allergens, detection methods, opportunities and challenges in establishing animal models of WA are summarized and discussed. Furthermore, an updated overview of the different modification methods that are currently being applied to wheat-based foods is provided. This study concludes that future approaches to food allergen detection will focus on combining multiple tools to rapidly and accurately quantify individual allergens in complex food matrices. Besides, biological modification has many advantages over physical or chemical modification methods in the development of hypoallergenic wheat products, such as enzymatic hydrolysis and fermentation. It is worth noting that using biotechnology to edit wheat allergen genes to produce allergen-free food may be a promising method in the future which could improve the safety of wheat foods and the health of allergy sufferers.

Detection of Species Substitution in the Meat Value Chain by High-Resolution Melting Analysis of Mitochondrial PCR Products

Substituting high commercial-value meats with similar cheaper or undesirable species is a common form of food fraud that raises ethical, religious, and dietary concerns. Measures to monitor meat substitution are being put in place in many developed countries. However, information about similar efforts in sub-Saharan Africa is sparse. We used PCR coupled with high-resolution melting (PCR-HRM) analysis targeting three mitochondrial genes—cytochrome oxidase 1 (CO1), cytochrome b (cyt b), and 16S rRNA—to detect species substitution in meat sold to consumers in Nairobi, Kenya. Out of 107 meat samples representing seven livestock animals, 11 (10.3%) had been substituted, with the highest rate being observed in samples sold as goat. Our results indicate that PCR-HRM analysis is a cost- and time-effective technique that can be employed to detect species substitution. The combined use of the three mitochondrial markers produced PCR-HRM profiles that successfully allowed for the consistent distinction of species in the analysis of raw, cooked, dried, and rotten meat samples, as well as of meat admixtures. We propose that this approach has broad applications in the protection of consumers against food fraud in the meat industry in low- and middle-income countries such as Kenya, as well as in developed countries.

High-Resolution Melting Analysis as a Tool for Plant Species Authentication

High-resolution melting (HRM) analysis is a cost-effective, specific, and rapid tool that allows distinguishing genetically related plants and other organisms based on the detection of small nucleotide variations, which are recognized from melting properties of the double-stranded DNA. It has been widely applied in several areas of research and diagnostics, including botanical authentication of several food commodities and herbal products. Generally, it consists of the main steps: (1) in silico sequence analysis and primer design; (2) DNA extraction from plant material; (3) amplification by real-time PCR with an enhanced fluorescent dye targeting a specific DNA barcode or other regions of taxonomic interest (100-200 bp); (4) melting curve analysis; and (5) statistical data analysis using a specific HRM software. This chapter presents an overview of HRM analysis and application, followed by the detailed description of all the required reagents, instruments, and protocols for the successful and easy implementation of a HRM method to differentiate closely related plant species.

Fluorescence-based quantitative platform for ultrasensitive food allergen detection: From immunoassays to DNA sensors

Food allergies are global health issue with an increasing prevalence that affect food safety; hence, food allergen detection, labeling, and management are considered to be important priorities in the food industry. In this critical review, we provide a comprehensive overview of several fluorescence-based platforms based on different biorecognition ligands, such as antibodies, DNA, aptamers, and cells, for food allergen quantification. Traditional analytical methods are generally unsuitable for food manufacturers to accomplish the real-time identification of food allergens in food products. Therefore, it is important to develop simple, rapid, inexpensive, accurate, and sensitive methods to improve user accessibility. A fluorescence-based quantitative platform provides an excellent detection platform for food allergens because of its high sensitivity. This review summarizes the traditional antibody-based fluorescent techniques for food allergen detection, such as the time-resolved fluoroimmunoassay , immunofluorescence imaging, fluorescence enzyme-linked immune sorbent assay, flow injection fluoroimmunoassay, and fluorescence immunosensors. However, these methods suffer from disadvantages such as the significant rate of false-positive and false-negative results due to antibody cross-reactivity with nontarget food components in the complex food matrix and epitope degradation during food processing. Hence, different types of fluorescence-based immunoassays are suitable for standardization and quantification of allergens in fresh foods. In addition, we summarize new fluorescence-based quantitative platforms, including fluorescence genosensors, fluorescence cell sensors, and fluorescence aptamer sensors. With the advantages of high sensitivity and simple operation, fluorescence biosensors will have great potential in the future and could provide portable methods for multiallergen real-time detection in complex food systems.

Are current analytical methods suitable to verify VITAL® 2.0/3.0 allergen reference doses for EU allergens in foods?

Food allergy affects up to 6% of Europeans. Allergen identification is important for the risk assessment and management of the inadvertent presence of allergens in foods. The VITAL® initiative for voluntary incidental trace allergen labeling suggests protein reference doses, based on clinical reactivity in food challenge studies, at or below which voluntary labelling is unnecessary. Here, we investigated if current analytical methodology could verify the published VITAL® 2.0 doses, that were available during this analysis, in serving sizes between 5 and 500 g. Available data on published and commercial ELISA, PCR and mass spectrometry methods, especially for the detection of peanuts, soy, hazelnut, wheat, cow's milk and hen's egg were reviewed in detail. Limit of detection, quantitative capability, matrix compatibility, and specificity were assessed. Implications by the recently published VITAL® 3.0 doses were also considered. We conclude that available analytical methods are capable of reasonably robust detection of peanut, soy, hazelnut and wheat allergens for levels at or below the VITAL® 2.0 and also 3.0 doses, with some methods even capable of achieving this in a large 500 g serving size. Cow's milk and hen's egg are more problematic, largely due to matrix/processing incompatibility. An unmet need remains for harmonized reporting units, available reference materials, and method ring-trials to enable validation and the provision of comparable measurement results.