Answer:
Isomers are defined as the molecules or polyatomic ions which have similar molecular formula but different in arrangements of atoms.
Isomers can be found in food items carrying glucose (C6H12O6), galactose or fructose, they all have the same chemical formula but differ structurally and chemically.
Glucose is found in vegetables and milk, galactose found in dairy products, and Fructose is found in fruit juices.