Cut surfaces of fruit and vegetables often become dark because (DPMT 1983; CPMT 1983)
A. Dirty knife makes it dark
B. Oxidation of tannic acid in the presence of trace of iron from the knife makes it dark
C. Dust of the air makes it dark
D. None o the above
Answer:B
Cut surfaces of fruit and vegetables often become dark because (DPMT 1983; CPMT 1983)
A. Dirty knife makes it dark B. Oxidation of tannic acid in the presence of trace of iron from the knife makes it dark C. Dust of the air makes it dark D. None o the above