Question

1.What is food poisoning?
How do we detect whether a foodstuff is fit for consumption
or not?

2.Write a short note on some common food preservation methods.​

Answer 1

Answer:

8th

Biology

Microorganism : Friend and Foe

Harmful Microorganisms

Food Poisoning and Food Pre...

Food Poisoning and Food Preservation

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FOOD POISONING - DEFINITION

Food poisoning, also called food borne illness, is illness caused by eating contaminated food. Infectious organisms including bacteria, viruses and parasites or their toxins are the most common causes of food poisoning.

For example, botulism.

METHOD OF FOOD PRESERVATION - CHEMICAL METHOD - DEFINITION

Preservatives like sodium benzoate are added to tinned foods and squashes.

METHOD OF FOOD PRESERVATION - STRONG CONCENTRATION AND CHEMICALS - DEFINITION

High concentration of solute causes plasmolysis and death of any bacteria that may creep in.

METHOD OF FOOD PRESERVATION - COMMON SALT - DEFINITION

Salt is mixed with food in order to prevent biodegradation under normal conditions.

Treatment with salt for preservation purposes is called curing.

For example, fish, pickles etc are preserved using salting.

Answer 2

Answer:

1. Food poisoning takes place when the individual eats contaminated food and in many cases, the food is adulterated by bacteria or viruses or parasite but in most common cases, the food is contaminated by bacteria. Using senses of sight, smell and taste is the best way to tell if food is no longer fit for consumption.

2. Common food preservation methods-

• Chemical Method-Salt and edible oils are two main preservatives that are used for ages to prevent microbial growth. This is why we add extra oil to pickles. Preservation by salt is known as salting. Salting helps to preserve fruits for the long term. Meats and fishes can also be preserved by salting. Other synthetic preservatives include vinegar, sodium benzoate, sodium metabisulphite, etc.
• Sugar-Sugar is another common preservative used in jams and jellies. Sugar is a good moisture absorbent. By reducing moisture content, it restrains microbial growth.
• Heat and Cold Methods-Boiling and refrigeration prevent around 70 per cent of microbial growth. Boiling kills microorganisms that cannot tolerate extreme temperatures. Thus, it helps in food preservation. Refrigerators have very low temperatures. Since microbes do not get the optimum temperature they need for growth, their growth is inhibited. Pasteurization developed by Louis Pasteur is used until today to preserve milk.
• Smoking-Smoking prevents dehydration in fish and meat and thus prevents spoilage. The wood smoke contains a large number of anti-microbial compounds that slow the rancidification of animal fats.
• Canning-The food contents are sealed in an airtight container at high temperatures. Meat, fish, fruits are preserved by canning.

Explanation:

Hope it helps. Thanks.