Blood is an amalgamation of various chemicals, so it would be not practical to test for each one of them. Thus, the majority of the tests for blood are actually testing for a solitary component, that is, heme, as blood comprises of an ample amount of heme and so it is comparatively easy to determine.
However, the plant peroxidases also comprise heme, thus, the blood test, which is actually a heme test, will come positive. This leads to an outcome known as false positive. Thus, in the case of forensics, one has to depend on other things also to prove the suspect's guilt or innocence.
One should not be surprised that these plant enzymes could interfere with tests for blood because :
The plant enzymes contain heme and the blood test been conducted is also known as a heme test therefore the presence of the plant enzymes in the blood samples will result in a positive heme test which can be termed as a false positive due to the interference of the heme present in the plant enzymes.
However heating the samples before carrying out the test will effectively deactivate the plant enzymes containing Heme.
Hence we can conclude that One should not be surprised that these plant enzymes could interfere with tests for blood because : The plant peroxides contain heme just like the blood which contains heme as well.
Learn more about Heme test : https://brainly.com/question/10122738
