Food preservation - Seven Wonders of the Microbe World (3/7)

Summary

Microbes play a dual role in food, aiding in the production of delights like cheese and beer, while also causing gastroenteritis through contamination. Ancient preservation methods like salting, drying, and fermentation are still used today to combat harmful microbes. Temperature manipulation, such as refrigeration and boiling, helps preserve food by inhibiting microbial growth. Canning, developed by Nicholas Appert, further extends shelf life. Alcohol and acidic environments like vinegar also deter microbes, ensuring food safety and quality.

Takeaways

• 🍽️ Microbes play a dual role in food, being essential for creating products like cheese, bread, yogurt, and beer, but also causing harm when they lead to foodborne illnesses like gastroenteritis.
• 🏥 In the UK, there are over ten million cases of gastroenteritis annually, often resulting from consuming food contaminated with harmful microbes.
• 🛡️ Ancient preservation methods like salting, drying, icing, pickling, smoking, and fermentation are still used today to prevent microbial growth and food spoilage.
• 💧 Microbes require water to grow, and by making food very sugary or salty, we can deny them this essential resource, thus preserving the food.
• 🌡️ Temperature manipulation is a key preservation strategy; refrigeration slows microbial growth, while boiling can kill most microbes, though some resistant bacteria require higher temperatures to be eradicated.
• 🔬 The French confectioner Nicholas Appert developed canning in the 1790s, a method that involves heating food in sealed containers to eliminate microbes through high temperatures.
• 🍶 Alcohol and acidic environments like vinegar are inhospitable to many microbes, making them effective for food preservation, as seen in the production of Branston pickle.
• 🧊 Refrigeration only slows down microbial growth, it does not kill all microbes, which means that food can still spoil if left for extended periods.
• 🔍 The script underscores the importance of understanding microbial behavior in food to ensure safety and extend shelf life, highlighting both the benefits and risks associated with different preservation techniques.
• 📚 The historical context provided by the script shows how human ingenuity in food preservation has evolved over time, from ancient methods to modern-day applications.

Q & A

What role do microbes play in food production?

Microbes are responsible for creating some of our most enjoyable food products such as cheese, bread, yogurt, and beer.

Which harmful microbes are mentioned in the script that can cause gastroenteritis?

The harmful microbes mentioned are Salmonella, Listeria, and E.coli O157.

What is the impact of consuming contaminated food on human health?

Consuming contaminated food can lead to gastroenteritis, which includes symptoms like nausea, vomiting, diarrhea, and stomach pain.

How many cases of gastroenteritis are reported annually in the UK according to the script?

In the UK alone, there are more than ten million cases of gastroenteritis each year.

What is one of the first things that happens to fresh food when left lying around?

If you leave fresh food lying around, microbes land on it and start to deteriorate the food.

What is one way ancient people discovered to stop food from spoiling?

Ancient people discovered that one way to stop food from spoiling is to try and preserve food.

List some methods of food preservation mentioned in the script.

Methods of food preservation mentioned are salting, drying, icing, pickling, smoking, and fermentation.

How can microbes be denied water to prevent their growth?

Microbes can be denied water by turning the food very sugary, for example making jam, or by putting salt on our food.

What is the effect of temperature on the growth of microbes?

Many microbes are sensitive to temperature and don't like cold or hot temperatures, so changing the temperature can help preserve food.

What is the common method of food preservation using high temperature under pressure?

Canning is a common method of food preservation using high temperature under pressure.

Who developed the canning method and what did he preserve using this technique?

The canning method was developed by the French confectioner Nicholas Appert. He preserved soups, vegetables, juices, dairy products, jellies, jams, and syrups.

How do alcohol and acid help in preserving food?

Many microbes can't survive in alcohol or acid conditions such as vinegar or pickling, making them effective forms of preservation.

What is the effect of refrigeration on microbes on food?

Refrigerating food slows down the growth of microbes but does not actually kill them.