Vitamins and food processing

Vitamins and food processing

1. Blanching

   • Before food is canned of frozen, it is usually heated very quickly with steam and water. Water-soluble and B group vitamins are reduced by blanching
   • Blanching is boiling fruit and vegetables for a short time to destroy enzymes before plunging into iced water to stop the cooking process

2. Canning

   • In the canning process, food and a small amount of water are heated in a sealed can to a very high temperature
     • This kills any dangerous micro-organisms & extends the shelf life of food
   • Vitamin B1 is lost from canned meats
   • Vitamin C is lost from canned vegetables and fruit. Can be as much as 80%
   • Water-soluble vitamins are lost through the water in the can if the water is thrown away

3. Pasteurisation

   • Leads to a loss of 10% of the vitamin B1 and B12 25% of vitamin C
   • Large amounts of vitamins A, D, C and B1 are lost during the production of condensed and evaporated milk but may have them added back in

4. Sterilisation

   • 30% of the vitamin B1 50% of vitamin C, folic acid and B12

5. Drying

   • Drying food removes water- soluble vitamins
   • All fruit can be dried by sun-drying, warm air drying or freeze drying
   • Vitamin A and E become concentrated in dried fruit
   • Vitamin C is normally added back in after processing

6. Food processing affects the sensory and nutritional properties of ingredients