Bulking agent refers to a class of additives that can make food volume expansion and organization loose, is indispensable in the production of bakery products, and is an important substance with wide application range. It is indispensable in the production of bakery products and has a wide range of important substances. It is of great significance to correctly grasp the composition, function principle and use method of all kinds of bulking agents to produce high-quality bakery products.

Expansion method of food volume

There are four ways to make the volume of food expand as follows

1, by the mechanical action of the air filled and saved in the dough or batter. Baking through the air by thermal expansion and make the food volume increased. Such as the production of sponge cake.

2, through the yeast in the dough or batter growth and reproduction fermentation produces carbon dioxide gas to make food volume expansion.

3、Chemical bulking agents such as baking soda, odor powder, baking powder, etc. are decomposed by heat or neutralization reaction to produce carbon dioxide and ammonia to make food volume expansion.

4, the water in the dough or batter is heated to water vapor and make the food bulky, such as puff production.

Classification and Characteristics of Bulking Agent

According to the principle of action of different puffing agent can be categorized as follows

1、Biological bulking agent that is yeast
(1) Classification and characteristics of yeast: yeast is usually divided into fresh yeast, active dry yeast and instant active dry yeast.

Fresh yeast has unstable activity, not easy to store, generally necessary before use activation and other characteristics; active dry yeast with easy to use, stable activity, can be stored at room temperature, need to be activated before use and other characteristics; ready to active dry yeast with high and stable activity, fast fermentation, storage, can not be activated before use and other characteristics.

(2) Growth characteristics of yeast: the suitable growth temperature of yeast is between 27-30℃, and the optimal temperature is 27-28℃, so the temperature should be controlled below 30℃ when the dough is fermented.

The temperature of maximum gas production is between 38-40℃, so the ambient temperature should be between 35-40℃ when the dough is fermenting. Below 10℃, yeast activity stops almost completely.

The pH value for yeast growth is between 5-6, below 2 or above 8, yeast activity will be greatly inhibited.

In addition, if the osmotic pressure is too high it will cause the yeast to undergo plasmic wall separation, making it impossible for the yeast to maintain normal growth until it dies. Therefore, be sure to pay attention to the dough can not add too much sugar and salt.

2、Alkaline bulking agent (i.e. baking soda and odor powder)
(1) Baking soda: scientific name sodium bicarbonate, molecular formula for NaHCO3, commonly known as small starter, gas production of 261cm3/g.

Baking soda in the dough mainly plays the role of horizontal expansion, commonly known as the “horizontal strength”. Therefore, it can be used in pastries such as peach crisp and bar crackers.

However, baking soda decomposition by heat (58 ℃ decomposition) after the residue of more alkaline Na2CO3 (commonly known as baking soda or alkali), on the one hand, will make the products deepen the color, on the other hand, it is easy to saponification reaction with fats and oils easily affect the taste of the product.

(2) odor powder: the scientific name of ammonia bicarbonate, molecular formula for NH4HCO3, commonly known as the big starter, the gas yield of 700cm3 / g. Because of its upward force and commonly known as up “Shunjin”. The decomposition temperature is 35℃.

Because of its decomposition product of ammonia, and ammonia is soluble in water, produce odor, solid can not be used in high moisture products (such as cakes, steamed bread, etc.). In addition, the odor powder expansion rate is too fast, resulting in uneven organization of the product, rough, so the dosage can not be too large.

3, compound puffing agent that baking powder (commonly known as baking powder, baking powder, baking powder)

Baking powder is formulated according to the principle of neutralization of acid and alkali, with the production of the pastry organization is uniform, fine texture, no large holes, normal color, pure flavor. However, due to the addition of alum in many baking powders, it is easy to make the aluminum content in the product exceeds the standard, which should be noted.

Puffing agent in the actual use of precautions

1, yeast: can not be used directly and ice water or hot water contact, so as not to reduce the activity or lead to death; with sugar and salt amount of high osmotic yeast should be used; can not be directly in contact with oil, so as not to form a layer of oil film on the surface of the yeast to reduce the vitality of the yeast; yeast activation can be placed in the yeast and sugar content of 1% -2%, the temperature of 30 ℃ of the water to carry out when the surface of the water produces a large number of bubbles, that is, indicating that activation is over.

2, alkaline bulking agent: from the advantages and disadvantages of the above baking soda and odor powder can be seen, the use of one of them alone will have some shortcomings, so in the actual application of the two need to be used in conjunction with the use, that is, at the same time add baking soda and odor powder, which can not only reduce the product in the Na2CO3 and ammonia residue, but also improve the use of odor powder due to the organization of the problem of the separate use of the poor.

In addition, due to the low decomposition temperature of odor powder and easy to volatile, solid in the use of the best and higher than 35 ℃ raw materials and direct contact, so as to avoid premature gas production. In the preservation of sealing, otherwise it will cause the volatilization of ammonia.

3, bulking agent: because of its encounter with water that produces acid-base neutralization reaction and carbon dioxide, so when using special attention should not be in direct contact with water, so as not to lead to the premature release of gas and the loss of expansion function.

The correct practice is to mix well with flour and then use. In addition, use non-aluminum bulking agent or use aluminum and non-aluminum bulking agent together as much as possible to prevent the harm caused by excessive aluminum.