Comparison

Food Safety

Table of contents

General

Food Safety

During food production, a wide variety of drugs is used, guaranteeing a stable production rate and having a strong influence on animal or plant health. Overuse of antibiotics can lead to antibiotic resistance, which is one of the major health management challenges of the 21st century. Drug residues in plants and animals can lead to potentially dangerous residues in food and the environment. The more short-term risks include allergens and toxicity. For example, high levels of histamine in seafood are often linked to scombroid poisoning, which causes an acute allergic reaction, vomiting, diarrhea, hypotension, rashes, and hives. Long term effects mean carcinogenicity and reproductive effects.

Food safety is a concern that spans the meat and seafood industry and forms the basis for providing nutritious and safe products to consumers. In order to comply with strict regulations and customer requirements, potential food safety hazards must be addressed and corrective action must be taken to actively monitor critical points in the process. This is only possible through permanent and efficient testing. Tests for foodborne pathogens like Listeria and Salmonella are commonly used to screen raw materials, verify the adequacy of process controls, monitor the environment and release the final product. Most importantly, test methods ensure the reliability, accuracy and precision of the AOAC or ISO17025 certified method.

Main categories

Dairy products

Dairy products are subject to particularly strict food safety and hygiene regulations. There are many potential risks for consumers in milk production and processing. Certain pathogens can be transmitted from milk-producing animals to humans, and pathogens causing food poisoning can also occur in and on healthy milk-producing animals. Pathogens can multiply extremely well in milk. Not least for these reasons, there are special regulations for milk production and processing that go beyond the general requirements for food. The safety of the food must therefore be guaranteed throughout the entire process. Preventive measures on the farm are crucial for controlling the health-endangering dangers ("Hazards").

For dairy products, there are several types of hazards to be aware of. In addition to chemical hazards from cleaning agents and disinfectants, food safety products from the life science sector mainly target biological hazards. Above all, this includes unsported bacterial pathogens (especially Salmonella, Campylobacter, pathogenic E. coli, zoonotic agents). Listeria monocytogenes and Staphylococcus aureus toxins can be harmful to cheese products. Bacillus cereus is a danger to milk and cream. The effectiveness of the preventive measures is verified by examining the milk in accordance with the milk quality regulation (for germ content; somatic cells as an indicator of mastitis; inhibitors) as well as examining the tank milk when it is delivered to the dairy.

In addition to various environmental contaminants such as chlorinated hydrocarbons, residues of antibiotics and aflatoxin M1 are classified as hazardous to health and are strictly prohibited in dairy products. Aflatoxin M1 is a mycotoxin, which arises as a conversion product in the liver of farm animals from the aflatoxins B/G (B1, B2, G1 and G2). Certain fungal strains of the genus Aspergillus flavus form such aflatoxins in moldy feed. The carry over effect is the transition of aflatoxins from feed to animal products. According to the current state of knowledge, the entry into muscle meat or eggs is to be regarded as negligible. The danger is that most of the aflatoxin M1 is excreted in the milk (and the urine), although there is a largely linear relationship between the aflatoxin B/G contamination of the feed and the aflatoxin M1 concentration measured in the milk can be assumed. The IARC (International Agency for Research on Cancer) classified aflatoxin M1 as a group 2B carcinogen (a substance with a possible carcinogenic effect in humans) (IARC 1993). When processing raw milk containing aflatoxin M1, the toxin can also migrate into secondary products.

The most commonly used class of antibiotics are β-lactams. The great success of β-lactam antibiotics in combating bacterial infections is due to their high specificity (inhibition of murein biosynthesis, which is restricted to bacteria). The effect is based on the splitting of the ß-lactam ring and the binding to enzymes that synthesize murein (prokaryotic cell wall component). The inhibition of the incorporation of mudslides ultimately leads to the lysis of the bacteria. A second group of β-lactam antibiotics unfolds their effect by inhibiting β-lactamases, which combine with the antibiotics by opening the β-lactam ring, but inactivate them in the process. β-lactam antibiotics are divided into 5 basic structures, whereby the so-called penam structure can be found in the well-known penicillins.

Seafood

Analysis of chemical contaminants in meat and seafood such as veterinary residues, toxins and pesticides is critical to ensure consumer safety and compliance with legal limits. Regardless of whether you test raw materials or certify product releases, meat and seafood companies must provide information on antibiotics and hormones and ensure that they meet the legal requirements of the exporting country. Why is testing so important? With today's trends, it's more important than ever to test meat and seafood products before they hit the market. These test drivers include: The development of “superbugs” or antibiotic-resistant bacteria and consumer desire for antibiotic-free foods. When it comes to meat and seafood analysis, we have a solution that will meet all of your testing needs.

Antibiotics are widely used to treat bacterial infections at various stages in fish farming. Overuse of antibiotics can lead to antibiotic resistance, which is a major challenge for health management in the 21st century. The use of pharmaceuticals is particularly widespread in sea shrimp farms, as this ensures sustainable production. Antibacterial or antimicrobial agents are used therapeutically and prophylactically. Nitrofurans (see meat products) are cheap and effective means of promoting growth and preventing disease. Several international authorities have already issued total bans on the use of such agents, including nitrofurans and GAP, and any confirmed concentrations in edible animal tissues are strictly prohibited. Sampling and monitoring procedures are intended to increase consumer safety.

The presence of high levels of histamine in fish, sulfites in shrimp, and shellfish toxins (including ASP, DSP, and PSP) are of particular importance to the health of consumers. Histidine is a biogenic amine that is produced from the amino acid histidine. This happens when fish is spoiled, especially dark-fleshed fish species (e.g. tuna, mackerel, sardine). Histamine is toxic to humans in higher concentrations (“scromboid poisoning”). With an intake of more than 40 mg of histamine, clear signs of intoxication occur.

Fluoroquinolones are a group of antibiotics that inhibit the activity of bacterial DNA gyrase. The group of fluoroquinolones mainly comprises enrofloxacin and the active metabolites ciprofloxacin, danofloxacin, norfloxacin, pipemidic acid, ofloxacin, and benofloxacin. One of the widely used fluoroquinolones is enrofloxacin, which was the first antimicrobial fluoroquinolone to be used in veterinary infections caused by E. coli, Salmonella, Pasteurella, Mycoplasma and Hemophilus. Compared to other gyrase inhibitors, they are characterized by a broader spectrum of activity. Since newer fluoroquinolones are not only effective against type II topoisomerase, but also against other types such as topoisomerase IV, the name gyrase inhibitor has meanwhile become internationally unusual. Some of them cause severe irreversible damage to the nervous and musculoskeletal system, which is why their use is severely restricted or prohibited in many countries.

Hot and in particular cold smoked fishery products are often contaminated with Listeria monocytogenes. These products are not subjected to any further germicidal treatment before consumption. With bacterial counts of more than 100 CFU/g, there is a risk of damage to health, especially for consumers from risk groups. The reason for the occurrence of L. monocytogenes are hygiene deficiencies in the production.

Unlike bacterial pathogens, toxins cannot be killed or neutralized during cooking. Since toxins are odorless and tasteless compounds, they are more difficult to identify. If they are consumed, for example through shellfish contaminated with marine toxins, poisoning can be the result. Since shellfish take up their food by filtering, toxins from the algae accumulate in the animal tissues, especially with larger algal blooms. This process is known as bioaccumulation. Although the toxins are mostly unsymptomatic to the shellfish themselves, consumption of these shellfish can lead to potentially serious illnesses in humans:

Amnesic shellfish poisoning (ASP) occurs when a person consumes shellfish contaminated with domonic acid, which is infected by Psuedo-nitzschia spp. diatoms. Razor clams are most often involved in ASP cases. Clams, crabs, and oysters can also be contaminated with domonic acid. In addition to nausea, vomiting, convulsions, and diarrhea, ASP can cause neurological symptoms such as confusion, dizziness, headache, seizures, irregular heartbeat, and short-term memory loss, which can be permanent.

Like ASP, DSP (shellfish diarrhea poisoning) is caused by a marine biotoxin produced by algae. In this case, however, the disease is caused by okadaic acid, which is produced by dinophysis (a dinoflagellate). Symptoms include stomach pain, nausea, vomiting, and diarrhea.

Paralytic shellfish poisoning (PSP) is caused by toxins derived from saxitoxin. Mollusks can become contaminated, as can gastropods such as moon snails and crabs that feed on other shellfish. The deployment of PSP is quick. Symptoms may begin as tingling of the lips and tongue, tingling in the fingers and toes, followed by loss of motor control in the arms and legs. Difficulty breathing occurs and if there is enough toxin it can paralyze the breathing and chest muscles and cause suffocation. The drastic symptoms of toxin poisoning once again emphasize the importance of effective diagnostics.

Saxitoxin (STX) is a toxin that is produced in dinoflagellates of the genus Gonyaulax by endosymbiotic bacteria. Resistant plankton filters such as mussels absorb and store it with food. Saxitoxin and its homologues, the gonyautoxins, have also been found in poisonous crabs of the South Pacific species Zosimus aeneus, Atergatis floridus, and Platipodia granulosa, as well as in some snail species that receive the toxin through their main diet. Saxitoxin presumably acts on the same receptor as tetrodotoxin and does not pass through the membrane. It blocks sodium channels from the extracellular side, which prevents the development of action potentials and thus the conduction of excitation in nerves and muscles.

Meat products

When farm animals are treated with antibiotics, residues of the drug are deposited in the animals' tissues. They can not only be detected in muscle tissue, but also in products such as milk, eggs or honey. The use of antibiotics in animal husbandry is widespread and often unavoidable. By keeping the animals in a confined space, infections can spread quickly. However, residues in food are potentially carcinogenic, toxic or trigger allergies. If the legal maximum residue levels are not exceeded, the health risk for the consumer is low. With the increasing use of antibiotics, more and more resistance is developing. If you come into contact with resistant germs, dangerous infections can develop that are difficult to treat because the usual drugs are no longer effective.

Antibiotic residues in food can be detected in several ways. An ELISA test enables precise quantification of individual antibiotics, while sample preparation with immunoaffinity columns and a subsequent HPLC test also allow the analysis of complex matrices.

Along with penicillin, streptomycin is one of the most commonly used antibiotics in veterinary medicine for mastitis therapy. They can occur in animal products if the waiting time after administration until slaughter is not long enough or if streptomycin is used improperly. Streptomycin is ototoxic and nephrotoxic in high concentrations. In food, however, low concentrations play a role, to which the consumer could be chronically exposed. This can result in allergic reactions, damage to the intestinal flora and the induction of resistance in pathogenic microorganisms.

The broad spectrum antibiotic chloramphenicol (CAP) has been widely used in animal breeding because of its excellent antibacterial and pharmacokinetic properties. The use on animals used for food production is now prohibited in the EU and other countries (zero tolerance), since residues in the products cause side effects in humans. Nevertheless, due to its good effects and low price, it is often used in animal husbandry. The principle of action of chloramphenicol is bacteriostatic, it inhibits protein synthesis in bacterial ribosomes.

Thiamphenicol and Florfenicol are also used in veterinary medicine as synthetic analogues of chloramphenicol. Florfenicol is a chemical compound containing chlorine and fluorine that belongs to the classes of aromatics and sulfones. Since the use of the broad spectrum antibiotic chloramphenicol is banned, florfenicol is often used as an alternative. Although this substance is less toxic, the European Union has set maximum residue limits (MRLs). The drug is not for use in animals that produce milk or eggs for human consumption.

Like chloramphenicol, tetracyclines inhibit ribosomal protein synthesis. They prevent the addition of the aminoacyl-tRNA to the acceptor sites of the 30S subunit of the ribosomes and thus the lengthening of the peptide chain. Tetracyclines are tetracyclic biogenic drugs that are synthesized by streptomycetes. Other tetracyclines, such as doxycycline and minocycline are partially synthetic derivatives made from other tetracyclines. They differ from other tetracyclines in particular in their pharmacokinetic properties, such as accumulation in the central nervous system and in the skin. Side effects of the tetracyclines are mainly due to their strong calcium-binding properties. They are built into the bones and are especially dangerous for pregnant women and newborns. Oral tetracyclines, like other antibiotics, can cause nausea, diarrhea, and vomiting. Due to their broad spectrum of activity, they also decimate the natural colonization flora. They can also photosensitize the skin. Tetracycline may have ototoxic side effects, especially on the sensory cells of the cochlea, which can be expressed in tinnitus and tinnitus. They are also considered a risk factor for excess brain pressure.

Nitrofurans are used as veterinary drugs for combating microorganisms in warm-blooded animals, e.g. in pigs and poultry, but also in fish and aquaculture. Nitrofurans are suspected of causing cancer. Therefore, these substances are banned throughout the EU for use in food-producing animals, which goes hand in hand with rigorous testing and monitoring of food processing companies. In animal experiments the nitrofuran compound furazolidone and its metabolites have been shown to be carcinogenic and mutagenic. Nitrofurans pass into the animal tissue and can then be present in meat as well as in eggs and milk together with the conversion products formed in the animal metabolism. The best-known nitrofuran compounds include Furaltadon (AMOZ) , Furazolidon (AOZ), Nitrofurazone (SEM) Nitrofurantoin (AHD).

Sulphonamides are often used as feed additives in calf and pig fattening. They are widely used in veterinary medicine to treat intestinal infections, mastids, pneumonia and other systemic infections. Sulfonamide antibiotics interfere with the folic acid metabolism of the bacteria. As a structural analog of p-aminobenzoic acid, they competitively inhibit the enzyme dihydropteroate synthase and ultimately block the formation of tetrahydrofolic acid. This disrupts the DNA synthesis of the bacterial cells. The sulfonamides used are sulfamethoxazole (in combination with trimethoprim as co-trimoxazole), sulfadiazine and sulfamerazine. The contamination of food of animal origin has been proven frequently (especially abroad). According to EU law, the maximum amount for all substances of the sulfonamide group of 100 µg/kg in muscle, fat, liver and kidneys and 100 µg/l in milk applies.

Grains

From harvest to the final product, many steps must be controlled and monitored in order to obtain a safe and high quality grain product. Grains are a major source of mycotoxins, but nuts, dried fruits, coffee, and spices can also be contaminated. Due to the widespread use of mycotoxins and their serious toxic effects, many countries have set limit values. Naturally occurring toxins that are relevant for food and feed safety are aflatoxins (see section “Milk products”), ochratoxins, ergot alkaloids, fusarium toxins, patulin and alternaria toxins. Reliable screening methods are a tool for producing safe products that meet all requirements.

The consumption of food contaminated with mycotoxins can cause mycotoxicoses (acute poisoning) as well as chronic diseases in humans and animals. In animals, mold toxins can also cause growth and fertility disorders - even after ingestion of very low concentrations. In addition, some mycotoxins can also be carcinogenic and damage the genetic make-up.

In the manufacture of baked goods, acids and sugar are often added to the products. In order to verify excellent nutritional values and to guarantee consistent quality, the ingredients of such products must be constantly analyzed. In order to detect compounds such as citric acid, sorbitol or sucrose, the use of enzymatic tests is widespread. These are easy to use and at the same time deliver precise results even in complex matrices. In addition to acids and sugars, enzymatic tests can be used to detect a number of other parameters in food - for example alcohols, salt, sulfite, cholesterol, ammonia or metals.

References

https://www.oekolandbau.de/verarbeitung/produktion/verfahren/milchprodukte/lebensmittelsicherheit-hygiene/

https://www.lgl.bayern.de/lebensmittel/chemie/schimmelpilzgifte/aflatoxine/aflatoxin_m1.htm

https://www.spektrum.de/lexikon/biologie/beta-lactam-antibiotika/37877

https://food.r-biopharm.com/de/industrie/getreide/

https://www.lgl.bayern.de/lebensmittel/warengruppen/wc_11_fischerzeugnisse/ue_2007_fischerzeugnisse.htm

https://www.neogen.com/neocenter/blog/unraveling-acronyms-what-is-asp-dsp-and-psp/

https://www.spektrum.de/lexikon/biologie/saxitoxin/58807

https://www.lgl.bayern.de/lebensmittel/chemie/arzneimittelrueckstaende/antibiotika/nitrofurane.htm

https://de.wikipedia.org/wiki/Tetracycline

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https://flexikon.doccheck.com/de/Sulfonamid-Antibiotikum