(1) water addition, when the water addition is in a suitable range, the whiteness value of steamed buns is relatively high. This is because when the amount of dough added is too low, the dough will be dry and hard, so it is difficult to make the pores of steamed buns fine and uniform, especially when the hard dough is over-proofed, the hole structure collapses, resulting in dark spots; However, when the amount of water added is too high, the light reflection is weakened and the whiteness of the product is reduced.
(2) The dough mixing time, if the dough mixing time is too long, will destroy the gluten network structure of the dough, and water will seep out of the dough, and even the steamed buns will not shrink or shrink, thus reducing the whiteness. It is difficult for materials with insufficient dough mixing time to be mixed evenly, or gluten does not reach the expanded state, and high whiteness cannot appear.
(3) Proofing time, the inside of steamed buns is even and small with the best whiteness. Insufficient awakening, too few or too small holes, or even no holes, is in a dead state, and steamed buns will not be white; Excessive proofing, large and uneven holes, can not produce good whiteness.
(4) The number of times of dough pressing (kneading), which makes the bubbles of dough disappear and a compact hierarchical structure appears, which is beneficial to the subsequent proofing to produce uniform small pores. Insufficient kneading, the air in the dough can not be completely eliminated, and the holes are not delicate; Over-rolling makes the dough ooze and sticky, and the internal structure is uneven, which also reduces the whiteness of the product. When the dough is pressed to the best state, the internal structure of the product is fine and the holes are uniform.
(5) Dough pH value Dough, when the pH value is 6. 5, the whiteness value of steamed buns is the highest. When the pH value of dough is lower than 6. 5, with the increase of alkali content, the pH value gradually increases, and the whiteness also increases. However, with the increasing amount of alkali, the dough gradually became alkaline, and the alkaline environment affected the fermentation of yeast in the dough, and the color of steamed buns began to darken. Even the combination of alkali and isoflavone pigments in flour turned steamed buns yellow, and the whiteness of steamed buns gradually decreased.
(6) Adding shortening, emulsifier, etc., shortening, emulsifier, sugar, etc. can be added to the ingredients for making steamed buns, which is mainly used in southern steamed buns. Adding shortening, emulsifier, sugar, etc., not only makes the skin of steamed buns bright, delicate in structure, soft and slightly sweet in taste, but also increases the whiteness of steamed buns. The principle of whitening is that emulsifier promotes the combination of oil and other ingredients in dough to form fine fat particles and disperse them evenly. Shortening oil and cake oil also belong to emulsified fat, which plays an important role here.