The VOLRO cracker - made from wholemeal and rye meal - was developed as a healthy children's food during the interwar period. 

The revolutionary recipe at the time came from Drs. Dr. h.c. Adolf Roos (1888-1974) and Karl Jakob (1877-1941). Dr. Roos discovered the connection between nutrition and healthy teeth for old age. This was the original VOLRO advertising slogan:

If you chew your bread well as a child,
you will build strong teeth for old age.