FOOD SCIENCE AND PROCESSING 3 (2+1)

Lesson 15 : Vegetables- Processing and Preparation

Effect of cooking on pigments

• Chlorophyll
• All green leaves and green colour vegetables like beans and peas contain chlorophyll.


• Effect of cooking in hot water
• When a green vegetable is put in boiling water, the green colour becomes brighter.


• Solubility in water
• Removal of the phytate group from the molecule of chlorophyll is catalysed by the enzyme chlorophyll found in some vegetables.
• Hydrolysis of the ester linkage yields a compound chlorophyllide which is water soluble.
• A limited amount of chlorophyllide produced during storage of certain green vegetables prior to cooking possibly accounts for the light green tint of the cooking water from them.