Microorganisms in food

Microorganisms (bacteria, fungi and yeasts) are usually involved in food spoilage. These microorganisms decompose the food to the point of inedibility. Sometimes dangerous germs can also multiply in food, leading to dangerous food infections, such as  salmonella . Microorganisms, which include bacteria, fungi and yeasts, are tiny creatures that accompany us everywhere in everyday life. There are those with very positive effects that we take advantage of in food production. These include, for example, lactic acid bacteria for the production of  yoghurt, yeasts used to make beer and leave yeast dough, and molds used in the production of blue cheese and camembert. However, there are also microorganisms that are undesirable in food because they lead to spoilage and can produce pathogenic substances. We now want to take a closer look at these.

bacteria

Bacterial foodborne infections are an often underestimated health risk for consumers. Bacteria produce metabolic substances that can be hazardous to human health. They usually cause  diarrhea  and vomiting. There can be serious consequences, particularly for young children, the sick and the elderly. If food is contaminated with bacteria, they often multiply explosively under good growth conditions. They especially like water and warmth. At lower temperatures, they grow less quickly, but they are only killed by heating. Heat-sensitive bacteria usually die at a core temperature of the food of 70-80°C. Less heat-labile bacteria are only killed at temperatures above 100°C.

• Preventive measures against foodborne infections are primarily based on maintaining personal and food hygiene. This includes thorough and regular washing of hands before and during food preparation.
• Especially when preparing food that can often be contaminated with bacteria, such as poultry, eggs, meat, seafood and raw milk products, you should work hygienically and then clean all work equipment thoroughly.
• Cook high-risk products such as minced meat and poultry thoroughly, ie for at least 10 minutes at 80°C.
• Eat food quickly after preparation or store refrigerated. Consume foods containing raw eggs on the day of preparation.

salmonella

Salmonellosis (= salmonella disease) is the   most common foodborne infection. Poultry, eggs, meat, fish and dishes made from these foods in particular can be contaminated with salmonella if they are not heated or not heated sufficiently. Typical signs of salmonellosis are  fever , headache, diarrhea and vomiting. These appear about 12 to 36 hours after eating the infected food and can last for a few days. In adults and people with an intact immune system, salmonellosis usually heals without complications after treatment. If older and immunodeficient people are affected, an infection with Salmonella can also be fatal.

Campylobacter bacteria

In addition to salmonellosis, foodborne infection by Campylobacter bacteria is important. These are mainly found in poultry meat and offal. But raw milk and  drinking water  can also be contaminated. The symptoms and course of the infection are similar to those of salmonella.

The EHEC bacteria

Enterohaemorrhagic Escheria coli ( EHEC ) is transmitted to humans through the consumption of contaminated food. Minced meat, meat products (e.g. Mettwurst, Teewurst, salami), unpasteurized  milk  and milk products play a special role here. On the other hand, the bacterium is transmitted from person to person through poor hygiene after going to the toilet. Infection manifests itself in watery diarrhea, colicky abdominal pain, cramps and vomiting.

staphylococci

Food contamination with staphylococci is mostly caused by humans. Staphylococci are found in the nose and throat, but also in wounds. In particular, the bacteria get into the food through improperly covered wounds on the hands. Eating these foods can lead to diarrhea, vomiting and abdominal cramps.

• Special care should be taken when preparing food for wounds, skin rashes, sore throats and other infections of the upper respiratory tract.

Listeria

Listeria can primarily be found in raw products such as minced meat, raw milk and raw milk cheese. Soft cheese with red smear or noble mold, shrimp, mussels, oysters, lobster and fish can also be affected. Listeria is a health hazard mainly for pregnant women. An infection (= listeriosis) can lead to premature labor,  miscarriage  and damage to the unborn child. However, listeriosis can also occur in children, immunocompromised and elderly people. It manifests itself in flu-like symptoms and can be accompanied by high fever and meningitis.

• Pregnant women should refrain from consuming raw milk, raw milk products, soft cheese with red smear or mold, raw minced meat (e.g. tartare). Meat, fish and other seafood should be sufficiently cooked before consumption.

Clostridien

The bacterium Clostridium botulinum produces a neurotoxin that is one of the most dangerous naturally occurring toxins. The disease caused by this toxin is called botulism. It can be fatal because it is a neurotoxin. Approximately 4 to 36 hours after admission, double vision, paralysis of the tongue and throat muscles and even respiratory paralysis occur. Clostridia are heat resistant and toxin formation occurs preferably in the absence of air. A risk therefore primarily emanates from canned, vacuumed and boiled foods that are not properly  sterilized became. Cases of poisoning are mainly known from home-made, insufficiently heated preserves. The weakly acidic canned vegetables, canned sausages, cured meat and raw ham are most frequently affected.

• The best prophylaxis against botulism is proper preservation of food in cans or jars, as well as adequate heating of food before serving.
• Food preserves that show any indication that they are no longer perfect, e.g. B. Cans with bombs or jars that are no longer properly sealed must be discarded.

molds

Molds are widely known as food spoilage. Food such as  bread  and baked goods, fruit, jam,  nuts ,  cheese , meat and sausage are often affected by mold. Some molds produce harmful toxins (= mycotoxins). A carcinogenic effect has been demonstrated for some mycotoxins. Mold forms a network of threads in the food that cannot be seen with the naked eye. Usually only the white or colored spots on the outer part of the food are visible.

• Food infested with mold should therefore generally be thrown away completely.
• Exceptions are, for example, hard cheese with mold colonization starting on the surface and jam made with more than half the sugar. With these foods, it is sufficient if the mold is removed from a large area.