we are going to see if i could distinguish real pomegranate juice than the one adulterated with pear juice. i happened to be right. and what if the substituted ingredient was potentially harmful. they are really worried about the next unknown. reporter: chinese suppliers added melamine to milk powder and that contamination led to the death of at least six children in china. authorities in europe uncovered horse meat being passed off as beef. and conservation group oceana released a study that showed a third of seafood worldwide is mislabeled. it s quite easy to dilute something and have it sneak through. reporter: the fda says it is dealing harsh punishments. the worst thing for a food company is have their brands