FOOD SCIENCE AND PROCESSING 3 (2+1)

Lesson 15 : Vegetables- Processing and Preparation

Betalains

Although these pigments are held tightly within cells in the raw vegetable, they diffuse rather rapidly into the cooking water resulting in the highly pigmented water associated with boiling beets. This problem is aggravated by cutting beet into small pieces and cooking leading to dull colouration in the boiled product. Since this colour is highly soluble in water, the best method of cooking beet root is to cook alongwith the skin, so that much of the colour does not leach out.

Effect of pH

• Betacyanins undergo colour changes parallel to anthocyanins.
• An acidic medium promotes a reddish colour, whereas a neutral or somewhat alkaline pH brings out brownish blue of the pigment.