A qualitative peptide biomarker approach to identify piscine gelatine in products to support food security.

Due to allergy concerns, it is mandatory under EU law to declare in food products all ingredients derived from fish. Gelatine is prepared from the waste collagen of animal carcasses, including piscine, bovine and porcine materials, and is an ingredient in a wide range of foods. The Elliott Review into the integrity and assurance of food supply networks highlighted requirements for analytical surveillance methods to support due diligence, food safety and authenticity. We present the development of a method to extract gelatine from foods and determine the presence of piscine gelatine by liquid chromatography-tandem mass spectrometry using a suite of sixteen piscine marker peptides. The method has been successfully applied to gelatine granules, capsules and composite retail food products. While a study is required to determine parameters including the limit of detection of this method, the data indicate the method is reproducible between replicates of sub-samples and applies to a range of piscine gelatines collected over 16 years. Once validation studies are complete, there is potential for enforcement officers to apply the technology to verify the authenticity of fish products to support consumers in ensuring food safety and also food provenance relating to animal origin.

Review: Methods to determine offal adulteration in meat products to support enforcement and food security.

Offal tissues carry a lower market value compared to skeletal meats in some global markets. The inclusion of offal in any meat product in the EU and UK must be declared on the label. While many technologies have been applied to the challenge of determining adulteration with offal in meat products, no single method has been recognised and validated as a reliable test to support legislative requirements. This literature review investigated appropriate methods to determine the adulteration of meat with offal. The aim was to identify technologies suitable for future validation to underpin a high throughput, low-cost method suitable for application by enforcement laboratories. Considering all of the methods, technologies which determine elemental composition and peptide markers were particularly highlighted as demonstrating potential for future development to determine a wide range of offal tissues to support the safety and integrity of the food chain.

Identification of novel peptides for horse meat speciation in highly processed foodstuffs.

There is a need for robust analytical methods to support enforcement of food labelling legislation. Proteomics is emerging as a complementary methodology to existing tools such as DNA and antibody-based techniques. Here we describe the development of a proteomics strategy for the determination of meat species in highly processed foods. A database of specific peptides for nine relevant animal species was used to enable semi-targeted species determination. This principle was tested for horse meat speciation, and a range of horse-specific peptides were identified as heat stable marker peptides for the detection of low levels of horse meat in mixtures with other species.

Screening method for the addition of bovine blood-based binding agents to food using liquid chromatography triple quadrupole mass spectrometry.

We report the development of a qualitative method to detect the addition of blood-based binding agents to food products. The method is based on the detection of species-specific marker peptides, fibrinopeptides, released from the blood protein fibrinogen during gelling of the blood protein by thrombin. The fibrinopeptides were isolated from foods spiked with commercial bovine binding agent by acid precipitation followed by enrichment using solid-phase extraction and analysed by liquid chromatography electrospray ionisation triple quadrupole mass spectrometry. Fibrinopeptide A was found to be an effective marker in fresh, processed and cooked food matrices spiked with 5% (v/w) bovine binding agent.

Development of a cell culture/ELISA assay to detect anticoagulant rodenticides and its application to analysis of rodenticide treated grain.

This study describes a generic biological screening assay designed to detect anticoagulant rodenticides based on their inhibitory action on the vitamin K epoxide reductase protein complex, resulting in an accumulation of under-carboxylated prothrombin or proteins induced by vitamin K antagonism (PIVKA-II). A combined cell culture/ELISA assay was optimized to measure PIVKA-II production by the human hepatoma HepG2 cell line cultured in the presence of anticoagulant rodenticides. The specificity and sensitivity of the assay was validated using 41 grain extracts containing representative concentrations of rodenticide or appropriate nonrodenticide control compounds. In all cases, PIVKA-II produced by HepG2 cells in response to grain extracts spiked with rodenticides was detected by ELISA, while PIVKA-II was not detected in supernatants collected from cells exposed to nonrodenticide controls. This represents a novel, class-specific biological assay for the detection of anticoagulant rodenticides present in contaminated grain.