It is true for J-Co and Dunkin Donuts use premix flour, it means in prmix was already in the mix with other bahan2 (such as: milk powder, sugar, improver, egg powder, flavor, etc.).
After my review of the antecedent material use. For premix donut around it like a distinguished ingredient described above. From the manufacturer is set up in such a way tepungpremix "recipe ingredient" antecedent who want to produce soft donut etc. So when the outlet (J-CO/Dunkin) just simply add water and fat (margarine / butter / shortening). Flour, sugar, eggs, salt, milk, improver, flavor is included in the premix flour. Jd endurance so surely they could LBH ingredientnya too long because the pH is set, the cleanliness of the bacteria was maintained. In addition to a distinguished work environment clean as well. Look at J-Co, which all use work gloves and cover your mouth, none had messy hair, wear a hat all. Very minimal contact with the hands directly.
Then they use the system which affect the durability jg donuts. If only they used the sponge dough system, meaning that there is a distinguished fermented dough in advance, made starter and let stand for 4 hours, yields a batter who must like scented fragrant tape (actually smell is a result of fermentation (CO2 and alcohol). Well from This makes the pH of the fermentation of the dough down, below 7. Thus when pH decreased, the fungus did not grow.
For the sponge dough is my system not obvious, what J-Co and Dunkin use it, because this system takes a long time and there is loss (water evaporation) from the fermentation process.
Then the starter dough mixer who has finished in the back with the rest of other ingredients, just in print, was developed (proofing) and in cooking. Fried was not arbitrary, they usually use solid oil (deep frying oil), with a temperature of 190-200 C. If you use liquid oil, will not be until the temperature at a temperature of 190 because 170 was smoky and they will lead to structure liquid oils damaged. If the solid oils in a special design to a temperature of 220, so when ready to fry the donuts who entered. Since it is very hot lsg create a thin layer of surface (mature in the outer skin) so that oil does not dip donuts. Each side is usually no longer than 1 minute. The result is good cooking produces high-donut donut ring, like a white ribbon around the donuts.
After that a new coating with sugar glazing (Fondant). When viewed J-Co has a coating machine such as a waterfall which can cover the whole donut. Well fondant makes donuts still wrapped tightly, thus reducing contact with air. Thereby also difficult to grow mushrooms. Fondant itself is made from sugar and its derivatives (glucose etc.) as an explanation about the above ingredients, one a function of sugar for a long LBH product durability.