Canning and Fish Packaging Technology

Unit 3 - Unit operations in canning

3.2.3.6.Purpose (or objectives) of exhausting

• To make the completely processed can ends flat or concave in order to indicate that the food inside is in good condition.
• To ensure that the cans especially at the ends do not gets deformed or dented during heat processing due to the development of high pressure.
• To reduce the oxygen level inside the can for the following reasons
• Low oxygen level inside the cans minimizes can corrosion inside and hence food will be preserved for a long time.
• Minimizes fat oxidation and subsequent spoilage of food.
• To retain nutritive value by prevention of nutrient destruction (Vitamin C).
• To prevent the germination of aerobic spore of bacteria and growth of aerobic bacteria.
• To accommodate hydrogen produced by acid foods.