BIOMOLECULES AND ENZYMES

Detailed explanation-1: -It is generally accepted that vitamin A as found in butter fat and cod liver oil is easily destroyed. Heating and aerating these fats for a short time or exposing them to air at room temperature for a longer period uusually deprives them of every trace of vitamin A.

Detailed explanation-2: -Vitamin C is easily destroyed by excessive heat and water, as well as exposure to air. For retention of vitamin C in cooked foods, it is recommended that foods containing vitamin C be cooked as fast as possible with less heat and small amount of water.

Detailed explanation-3: -Vitamin C can be destroyed by heat and light. High-heat cooking temperatures or prolonged cook times can break down the vitamin. Because it is water-soluble, the vitamin can also seep into cooking liquid and be lost if the liquids are not eaten.

Detailed explanation-4: -Vitamin A is readily destroyed upon exposure to heat, light, or air. The vitamin, which functions directly in vision, is converted into retinaldehyde, a component of a light-sensitive pigment called rhodopsin (visual purple), which is present in the retina of the eye.