Characterization of the edible bird's nest the “Caviar of the East”

After simple nitric acid treatment, visual examination and comparison of whole nests adulterated with karaya gum, red seaweed, and Tremella fungus against the authentic white nest revealed that levels of adulteration as low as 1.7%, 1.8%, and 3.5%, respectively, could be identified visually. In the case of finely ground nests, the visual detection level was higher for all three adulterants: 1.1% for karaya gum, 1.2% for red seaweed, and 2.0% for Tremella fungus. The use of a reflectance colourmeter rendered this test even more sensitive, allowing detection at even lower levels.