Class 8ScienceMicroorganisms: Friend and Foe

Food Preservation

Microorganisms spoil food by growing in it. Methods to preserve: 1) Salt — draws out water (dehydrates microbes). 2) Sugar — in jams and jellies. 3) Oil and vinegar — prevent oxygen. 4) Pasteurization — heat to 70°C for 15s (Louis Pasteur). 5) Refrigeration — slows microbial growth. 6) Preservatives — sodium benzoate.

How to study this topic

Read the core explanation once without solving.
Open the formula links below and connect them with the topic meaning.
Practice the 10 example pages one by one.
Use the AI ask page for text, voice or image-based doubts.

10 example pages

Concept check 1

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on concept check and show the working clearly.

Definition to application 2

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on definition to application and show the working clearly.

Formula warm-up 3

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on formula warm-up and show the working clearly.

Reasoning practice 4

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on reasoning practice and show the working clearly.

Board-style short answer 5

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on board-style short answer and show the working clearly.

Mistake correction 6

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on mistake correction and show the working clearly.

Visual interpretation 7

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on visual interpretation and show the working clearly.

Applied word problem 8

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on applied word problem and show the working clearly.

Revision challenge 9

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on revision challenge and show the working clearly.

Exam recap 10

For Class 8 Science, explain or solve a food preservation question from the chapter "Microorganisms: Friend and Foe". Focus on exam recap and show the working clearly.