Why do some foods test positive for glucose but don't taste sweet?

The foods that are the carbohydrates, which dissociate into glucose to discharge energy. The foods, which are highest in glucose are starches and are sweet in taste. Some of the foods test positive for glucose, however, do not taste sweet because the over-ingredients overpowers the sweetness taste, and these ingredients are much more stronger than the glucose.  

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg