1, stinky tofu smells bad because after a long time of fermentation of soybean products, will produce hydrogen sulfide and methylamine, tryptamine and other substances, these things are volatile and with a special smell. Eating smells because the protein contained in beans under the action of microorganisms, hydrolyzed into peptides and amino acids containing fresh flavor.

2, part of the protein will be hydrolyzed into a variety of amino acids, of which the proportion of glutamic acid is higher. Because glutamic acid belongs to the fresh flavor amino acid, is a component of monosodium glutamate, so it has fresh flavor, so it makes stinky tofu fresh and delicious. Especially stinky dried tofu, such as Changsha stinky tofu production process can be flavored fermentation and non-fermentation in two forms, the fermentation process is through the fermentation and the emergence of stink is from the microbes on top of the tofu fermentation of proteins and the emergence of sulfide, indole formation, which is still a part of it.