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 beverages or food that contain no sweet taste or less sweet taste, it does not mean that they have negative test for glucose.

Explanations:

Sweetness is being feel, when it interact with taste bed (tastes organ on tongue). Sucrose is consider as a standard sweetener having rating 1. While is almost sweetener but its rating is 0.7 only that's why some time we don't feel sweetness after using such a food that contain glucose.

Conclusion:

Actually, the metabolic component are breakdown into simpler carbohydrates like sugar, fructose that become source of energy in blood stream. These sugar like glucose are less sweet than sucrose. So we sometimes don't feel sweetness.