Food adulteration is classified as the intentional addition of a foreign or inferior quality substance or element; by replacing a more valuable substance or element with less valuable or inert ingredients. (1)
Can be separated in different categories:
1. Substitution - Process of replacing a nutrient, an ingredient, a food or part of a food (often one with high value), with another nutrient, ingredient, food or part of food (often one with lower value).
Examples: Proteins being substituted by fat; On Ingredients - high value oil substituted with lower value oil (sunflower oil sold as extra virgin olive oil); addition of chicken meat to “goose and pork only pâté”; authorized GMO product not labelled as GMO. Species substitution - high value fish species substituted with lower value fish species when selling processed products (fillets, fish pies).
2. Dilution -Process of mixing a liquid ingredient with high value with a liquid of lower value to expand the total volume and reduce the concentration.
Example: addition of water to fruit juice or to milk.
3. Removal - Removing a constituent that should have been present in the product
Examples: removing of essential oils from herbs and spices sold as whole spice; removing piperine from pepper; removing omega 3 components from fish.
4. Unapproved/undeclared enhancement -Adding unapproved and undeclared compounds to food products in order to enhance their quality attributes.
Examples: melamine in milk (adulteration aimed at enhancing nitrogen content in already diluted milk); use of unauthorized chemicals in spices (lead chromate in curcuma).
5. Unapproved/undeclared treatment, process or product
Examples: Pesticides; growth promoters; handling, packaging, transport, storage (products not stored/transported correctly, at the correct temperature, proper packaging, re-freezing); decontamination (chemical treatment, additives, biocides, irradiation); Veterinary medicine; GMO and clones
6. Concealment - Process of hiding the low quality of food ingredients or products.
Example - diseased, contaminated, filthy, putrid meat and fishery products treated with food improvement agents or unauthorized additives (nitrate and nitrite, colorings, enzymes, flavorings, antioxidants, carbon monoxide treatment); mix of liquids or solids containing residues or contaminants to reach legal limits (MRL or ML). (1)
Nowadays, there is a growing trend among food manufacturers to use adulterants, either unintentionally due to lack of knowledge or resources, or intentionally to maximize profits. This intentional adulteration poses risks to public health as manufacturers prioritize profit over consumer well-being. In the context of increasing interest in vegan diets for health and religious reasons, some manufacturers adulterate vegetarian food with meat to enhance taste and aroma, resulting in fraudulently labeled products. Chicken contamination in vegetarian food is a common form of adulteration, particularly in vegetarian sausages, meatballs, and nuggets. The preference for chicken meat stems from its ability to enhance flavor and scent compared to other available taste enhancers. However, intentional, and unintentional chicken meat contamination poses significant health risks, especially for individuals allergic to chicken, as these allergies can be severe and even life-threatening. Allergies to chicken meat often extend to other bird meats as well. (2)
DNA-based detection methods have gained attention for their speed and accuracy in identifying food adulteration. These methods, such as polymerase chain reaction (PCR), can detect traces of meat DNA in vegetarian food products. PCR is capable of multiplying and amplifying DNA or RNA strands within minutes, making it effective for detecting even small amounts of meat DNA used as taste enhancers in vegetarian foods. Routine PCR testing in laboratories can identify meat contamination and other forms of adulteration involving various animals.
However, there are challenges in detecting food adulteration. Analytical methods can vary depending on the sample type (solid, semi-solid, or liquid) and whether the sample is cooked or uncooked. Additionally, using a specific marker is crucial, as the marker must be highly specific to accurately identify the adulterant present. Overcoming these challenges is essential to maintain consumer trust and prevent the misleading of consumers through food adulteration.
DNA-based detection methods have gained attention due to their accuracy, specificity, and time efficiency compared to other physical and chemical methods. One challenge in detecting food adulteration is the availability of specific markers, especially considering the geographical variations and diverse types of processed food and contaminations. DNA-based methods offer advantages in detecting biological adulterants since DNA is present in all cellular organisms. Various techniques such as microarray, southern blot, polymerase chain reaction (PCR), and Random Amplified Polymorphic DNA can be used. (2)
PCR as the ideal method:
PCR (polymerase chain reaction) is considered the ideal detection method for various reasons. It can produce large amounts of DNA products from a single template, and different types of PCR, such as Real-Time PCR and reverse transcriptase PCR, offer specialized features like real-time quantification and the ability to amplify DNA from RNA templates. PCR is beneficial for identifying pathogens in food and detecting meat contamination, even after processing methods like baking, frying, or boiling. It is a simple, accurate, and time-efficient technique that can detect different types of meat and processed food. (2)
However, PCR has some limitations. It is not highly sensitive, and proper DNA extraction from processed food samples can be challenging. The impurities in the extracted DNA can inhibit or alter the PCR results. To overcome this, the CTAB DNA extraction method (Implemented in Biopremier Food DNA Extraction Kit) is recommended for extracting DNA from vegetarian processed food samples. The purity of the extracted DNA can be determined using a spectrophotometer. In the case of detecting meat DNA in vegetarian food samples, the DNA extraction should include the meat DNA extraction using a standard protocol.
Once the DNA is properly extracted, PCR can be conducted using specific primers to detect the targeted species in the sample. For identifying meat and fish contamination in vegetarian food, three types of primers can be used: one to detect mammal meat DNA, another to detect fish and another to detect vegetarian food substances, considering the product is marketed as "vegan food.". Using these primers in PCR can be an ideal approach to identify contamination in vegan food. (2)
Instances of food manufacturers contaminating various types of food with meat are quite common, particularly in the processed food sector. One prevalent form of adulteration involves mixing cheap types of meat with more expensive ones to reduce production costs. The addition of pork meat to other processed meats is a frequent occurrence and poses significant concerns due to religious and health reasons. Research has also uncovered instances of fraudulent labeling, with turkey meat being identified in products labeled as chicken. Additionally, there have been reports of food manufacturers contaminating vegan food products with meat. In the United Kingdom, pork and turkey traces were detected in two types of vegetarian food products. Given these findings, further investigation into the contamination of chicken meat in vegetarian food is warranted. (2)
Flavor, which encompasses taste and aroma, plays a crucial role in the food industry. Nowadays, flavor additives are extensively utilized by food manufacturers in various food products. One prevalent type of food additive commonly used in ready-to-eat meals is meat stock cubes, specifically beef and chicken cubes. These cubes serve as enhancers of taste and smell. Research suggests that chicken, due to the chemical reactions that occur during cooking, possesses the ability to enhance flavor. However, factors such as chicken breed, bird diet, and the presence of free amino acids and nucleotides also contribute to the flavor of chicken meat. Postmortem factors like irradiation, high-pressure treatment, cooking methods, antioxidants, pH levels, and aging further influence the flavor profile.
Chicken cubes are widely employed as flavor enhancers in many countries, including Sri Lanka. These cubes, available in both chicken and beef varieties, are essentially concentrated broths. They are utilized in a variety of cuisines, including vegetarian food products, to enhance the flavor of various dishes.
Food adulteration is a significant global issue, driven by economic incentives that lead food manufacturers to alter their products. This adulteration has had various impacts on consumers, particularly those who abstain from certain foods due to health or religious reasons. As a result, consumer confidence in food manufacturers has been weakened. To avoid mislabeling or misrepresentation, it is crucial to implement rigorous and stringent measures at every stage of the supply chain. Equally important is the establishment of a culture throughout the supply chain that discourages food fraud and emphasizes the significance of consumer trust. (3)
Your team serves as your eyes and ears, offering valuable insights into any issues within your business or processes that require attention. Engaging with them, fostering communication, and valuing their input will help identify problems and propose practical solutions. In this case, these issues may lie within the supply chain, contributing to unintentional food fraud. Reducing the risk of food fraud relies not only on robust processes and clearly defined policies but also on cultivating a culture that aligns with and supports these guidelines. (3)
Various detection methods have been discussed with PCR emerging as the most reliable DNA-based technique for identifying such adulteration. Nevertheless, scientists continue to innovate novel methods for rapid and easy detection of food adulteration. It is our responsibility to minimize food adulteration and promote the production of healthy food products worldwide. This approach can lead to improved information sharing practices and encourage whistleblowing throughout the entire food industry, thereby mitigating the overall risk of food fraud. (3)
BPMR is providing a NEW KIT - SUPREME REAL TIME PCR DETECTION TEST KIT Vegan, designed for the detection of small amounts of animal DNA (down to 10 pg/PCR reaction and 0.1% of animal DNA in 50 ng of total DNA) in one real-time PCR reaction, after a sample processing extraction step.
Vegan Food Fraud Detection with Real-Time PCR kits
- BPMR kits take full advantage of real-time PCR to enable a quick and reliable method for vegan food fraud detection.
- These kits are based on gene amplification and detection using real-time PCR with an DNA-based assay.
- Ready-to-use PCR reagents contain everything required to detect targeted organisms with high sensitivity and specificity.
- The SUPREME REAL TIME PCR DETECTION TEST KIT Vegan allows the detection of mammal and avian DNA and fish DNA.
- The kit includes an internal control (IC) that allows the exclusion of false negative results.
- Our kits have incorporated a Hot Start polymerase to enable reliable PCR amplification. The mix offers highly reproducible DNA synthesis.
Various tests were performed to ensure both kit quality such as inclusivity, sensitivity, and exclusivity:
- Inclusivity: A total of 22 food samples with animal DNA were tested. All the meats tested with the kits were detected corresponding with 100% inclusivity.
- Sensitivity: Target amplification was observed in samples contaminated with at least 10 pg of animal DNA and a detection of 0.1% of animal DNA in 50 ng of total DNA.
- Exclusivity: A total of 19 food samples without meat/fish DNA were tested with the kits and showed 100% exclusivity with no positive results. Additionally, in-silico analysis was performed for insects and reptiles and no cross-reactivity was observed.
- For DNA extraction, our BIOPREMIER DNA Extraction from Food kit allows efficient extraction and purification of DNA samples from challenging matrices containing high levels of polyphenols. Furthermore, the purified DNA products can be used directly on the PCR.
BPMR present to you a global solution from the extraction and purification of DNA from food sources for fraud identification.
- Quick results (one-two days) in few steps: first Food Source DNA Purification, followed by Fraud Testing and lastly Data Analysis. Check below the “A simple Three-step Protocol”.
- Accessible and easy to use thanks to a ready-to-use kits.
- Harmonized protocols for Real Time PCR detection.
- Compatible in the most used real time PCR equipment’s.
- Includes Positive and Negative PCR controls and Internal control.
This flexible and sturdy protocol fits smoothly in any analytical lab workflow to reach the best productivity! Ranges from low to high throughput testing, with simple to use user interface, to, in the end, provide efficient sample interpretation.
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(1)Food fraud categories – draft proposal - https://food.ec.europa.eu/system/files/2021-04/food-fraud-reports_20210129_pres02.pdf
(2)Detection Of Chicken DNA In Ready To Eat Vegetarian Food. (2022, February 18). Edubirdie. Retrieved June 16, 2023, from https://edubirdie.com/examples/detection-of-chicken-dna-in-ready-to-eat-vegetarian-food/