1.2.1.4 Identification of plant and animal protein in feed

1.        Mix 1-2 g test sample with 100 ml boiling water or boil the mixture for 2-3 min. Place a few ml of the cooled mixture in test tube and add 5-6 drops of iodine solution. If starch is present, the mixture turns blue.

2.        Spread 1-2 g test sample into  a petri dish. Add 5-6 drops of iodine solution and let stands for 10 min. A purple brown colour indicated the presence of plant fibre, whereas yellow indicated animal fibre (protein) using a microscopic examination.