Changes in the composition of the dough that occur during the fermentation process

Under the action of a variety of enzymes such as yeast invertase, maltase and brewing enzyme, the sugar in the dough is decomposed into alcohol and carbon dioxide, as well as the complex action of various microbial enzymes, and various sugars, amino acids, organic acids, esters are produced in the dough, so that the dough has an aromatic smell, etc., and the above complex process is called dough fermentation.

Biochemical changes in dough fermentation:

1. Sugar variations.

The soluble sugars contained in the dough include monosaccharides and disaccharides. Among them, the monosaccharides are mainly glucose and fructose. Disaccharides are mainly sucrose, maltose and lactose.

Monosaccharides can be fermented directly by yeast's brewing enzymes to produce alcohol and carbon dioxide. Disaccharides, on the other hand, are not directly fermented, but they also end up producing alcohol and carbon dioxide.

2. Changes in starch.

Starch is broken down into maltose by amylase during fermentation.

3. Changes in proteins.

Proteins are broken down by the proteases that wheat itself carries. The breakdown of this protein is only a very small amount, resulting in a small amount of amino acids.

4. Reaction to generate acid.

At the same time, various organic acids are produced during fermentation, which reduces the pH of the dough. These organic acids are mainly lactic acid, and there are also small amounts of acetic acid, formic acid, succinic acid, etc.

5 Generation of ester compounds.

The above-mentioned organic acids react with alcohol to obtain ester compounds.

6. Generation of carbonyl compounds.

Carbonyl compounds are mainly aldehydes and ketones. It is an unsaturated fatty acid that can only be felt by shortening, cream, vegetable oil and other oils and fats added to the oil components or excipients in flour, and under the action of a small amount of lipase in wheat flour and oxygen in the air, it is first oxidized into oxides, and then under the action of enzymes secreted by yeast, a variety of complex aldehydes and ketones are generated.

Because the yeast uses the glucose in the flour as nutrition, it multiplies and produces a large amount of carbon dioxide gas, which is surrounded by the gluten network formed by the protein in the flour, and the dough swells and loosens.

The resulting change is the incomplete respiration of the organism. Yeast breaks down glucose to produce energy and carbon dioxide. Ibid.

How flour is turned into bread is inseparable from one amazing key substance, which is yeast. The main function of yeast is fermentation, and the key to making the dough expand, become larger, softer, and full of pores is to control the degree of fermentation of yeast in the dough. It's important to grasp the following points!

1) Temperature. Yeast is active at 0-55 and gradually loses activity above temperature.

The temperature at which yeast is suitable for reproduction is 22 -28, which is the temperature required for the dough.

The temperature suitable for dough fermentation and gas production is 32 -38 The temperature required by the proofing chamber.

The growth rate of yeast will be significantly reduced when it is below 20 and above 40.

When the dough temperature exceeds 30, although the gas production rate is favorable, the total gas production of yeast decreases and affects the quality (no stamina).

2) The influence of pH value and water quality.

Yeast is more suitable for growing under weakly acidic conditions, and the pH value of the dough is kept between 4 and 6 in actual production, and most of the water quality is affected by the pH value.

The water quality is hard, which refers to the water containing more minerals, and the use will reduce the solubility of protein, make the gluten too hard, the toughness is too large, inhibit yeast fermentation, and the finished product has a thick skin and a rough taste.

3) The effect of osmotic pressure.

If the amount of sugar and salt is too high (sugar, salt, yeast, and water are diluted at the same time), the yeast cell membrane will be destroyed, so that the fermentation rate will be reduced, and the reproduction of yeast will be inhibited.

Of course, yeast can still survive and ferment at high concentrations, and dry yeast has stronger adaptability than fresh yeast in this regard.

4) The effects of sugar.

There are four types of sugars that can be used by yeast in dough: glucose, fructose, sucrose, and maltose. The first two can be directly used by yeast, sucrose must be decomposed into grape enamel and fructose by invertase in yeast to be utilized, malt enamel is released by the decomposition of damaged starch in flour by amylase, and then converted into glucose by invertase in yeast, which can also be used by yeast.

5) Other factors affecting yeast fermentation.

Such as alkali, preservatives, high oil content or too early will affect the normal reproduction of yeast.

Instant dry yeast dissolves quickly and has high activity, but this type of yeast is very sensitive to oxygen, and once the oxygen content in the air exceeds it, it will lose its fermentation ability, so this kind of yeast is vacuum-packed in tin foil, and needs to be sealed and stored after opening to be used as soon as possible.

Acidity Generally, it is necessary to add acid or promote fermentation to produce acid before fermentation, otherwise harmful microorganisms will multiply;

Acid-containing foods have a certain antiseptic ability, but when there is aerobic energy, there will also be mold growth on the surface, and the acid will be consumed and will lose the antiseptic ability;

Acidity in food can also decrease due to the breakdown of proteins to produce ammonia.

Alcohol has an antiseptic effect, mainly depending on its concentration, 12-15% fermented alcohol by volume inhibits the growth of microorganisms.

Generally, the alcohol content of fermented beverage wine is 9-13%, which lacks preservative ability, and pasteurization or preservatives are required;

If alcohol is added to the beverage wine to make the content reach 20%, there is no need for sterilization treatment, and it has antiseptic and antibacterial effects.

At the beginning of culture fermentation, the rapid multiplication of the culture is expected to inhibit the growth of other bacteria.

Temperature The temperature required for fermentation varies depending on the type of microorganisms, and temperature fluctuations can affect the fermentation effect.

Different microbial fermentation results in different acidity and flavor of the product, and the products of multi-microbial fermentation have better quality.

Adjusting the fermentation temperature during mixed fermentation allows the growth rate of different types of microorganisms to be controlled, so as to achieve a purposeful fermentation effect.

Oxygen Proper supply or cut-off of oxygen can promote or inhibit the growth of (fermentation) bacteria and can lead to production in the direction of producing the desired metabolites;

Lactic acid bacteria are facultatively anaerobic, and only hypoxia can convert sugar into lactic acid; When the yeast has sufficient oxygen, it reproduces more than fermentation, and when it is hypoxic, alcoholic fermentation mold is completely aerobic;

Mold is completely aerobic.

Different concentrations of salt solutions have different effects on microorganisms, and salt can be used as a means to select suitable microorganisms for growth activities.

Wheat flour gluten size. 2 Whether the blender is variable speed. 3 How much water to add to the dough.

4. The water quality is soft and hard. 5. The temperature of the dough is high or low. 6. The pH of the dough is high or small.

7. Auxiliary raw materials such as salt, sugar, milk powder, oil, dough improver and emulsifier. 7. What are the process requirements for dough fermentation?

Consequences of fermentation for too long:

1. If you ferment too much, it will taste like wine and it will become sour.

2. The structure of the bread will also be rough and grainy. The shape will also be unsightly.

3. The dough will be inelastic, the bread made will be inelastic, and the baked bread will not taste good.

Fermentation is a complex process. To put it simply, yeast breaks down starch and sugar in flour to produce carbon dioxide gas and ethanol. The carbon dioxide gas is encapsulated by the gluten, forming a uniform and fine pores that make the dough swell.

Fermentation needs to be controlled just right. If the fermentation is insufficient, the bread will be small in size, the texture will be coarse, and the flavor will be insufficient; If the dough is over-fermented, it will develop a sour taste and become sticky and difficult to handle.

Fermented dough has the characteristics of full shape, loose and porous, soft texture, etc., and the product has a unique flavor that is different from other dough products. In order to make a good quality pizza, the dough must be well risen. Dough fermentation is one of the main steps in the production of pizza dough, and the quality of pizza dough fermentation directly affects the final quality of the finished pizza.

The fermentation of dough requires the accumulation of time to complete, but judging whether the dough is fermented can not rely on time to judge, we must learn to use various methods to judge its state, to achieve the classification management of dough.

How can you tell if dough is ripe for fermentation? The method of judging the fermentation and maturity of dough can be considered from the following.

1. Visual inspection.

After the dough has been fermented for a certain period of time, if the dough has reached the state of fermentation, it will be about twice as large as before it was fermented. For example, the low-temperature refrigerated fermented dough is twice as large as it was after 24-36 hours of fermentation.

2. Hand touch.

Gently press the dough with your fingers, and after the fingers leave the dough, the surface of the dough appears to be depressed (no falling and no rebound), indicating that the dough has fermented and matured, because the fermented and mature dough has suitable elasticity and soft stretchability. If it rebounds (returns to its original shape) soon after pressing, it is due to insufficient fermentation, but the dough continues to sink, indicating that it has been over-fermented.

3. Olfactory method.

After fermentation and ripening, the dough has a slight sour taste and aroma of wine. If you can't smell a little sour, it means that the fermentation is insufficient; On the contrary, if the sour smell is very strong, it is a sign of overfermentation.

4. Slapping method.

When we pat the leavened dough with our hands, it will feel fluffy to the touch and the sound will be empty, like a ripe watermelon. On the other hand, the dough that does not rise enough will have a low sound when beaten, and the touch will be very firm and not fluffy.

5. Pulling method.

Pull the dough by hand, observe the size and number of bubbles in the tissue, the thickness of the membrane and net, and if the inside is sac-like, it is fermented and matured. If you don't, you don't have enough fermentation.

In addition, after the dough is fermented and matured, the general temperature will rise slightly by 4-6, and its pH value is about 5.

We all know that dough is the most important semi-finished product of a pizza shop, and if the dough is not fermented well, even if you apply the best pizza sauce, cheese, filling, etc., the failure of the pie base cannot be covered up, and it is a defect that cannot be made up in any way. Therefore, in the daily management of dough, it is necessary to have its own management system, such as the number of dough, the number of dough, the time of dough preparation, and the daily inspection of dough.

Whether the bread dough is fermented in place should be judged by the fermentation state, not by the fermentation time.

A common method for the identification of fermentation and maturation.

1) Falling back method: After the dough is naturally fermented for a certain period of time, the ** part will be cooked when it collapses slightly.

2) Hand touch method: Gently press the dough with your hand, and the dough will not bounce back or fall when the fingers leave, indicating that it is fermented and mature.

3) Temperature method: After the dough is fermented and matured, the general temperature rises by 4-5 degrees Celsius, and it can be measured with a thermometer.

The best way to check the degree of fermentation is to insert one finger into the dough, and if there is a depression in the fingerprint after the finger pulls out the dough, it means that the fermentation time is not enough; If the dough around the fingerprint is neither ** nor sagging, it means that the dough has risen just right; If the dough around the fingerprint sinks rapidly, it means that it has been over-fermented, and you can add baking powder to knead it well.

After the dough is fermented, it should be kneaded again, covered with plastic wrap and placed for about 10 minutes, cut into the desired shape and placed for twenty or thirty minutes (the length of time depends on the degree of the dough fermented for the first time, if the first fermentation is insufficient, it can be left for a longer time at this time), and it can be steamed in a steamer.

The swelling effect of the leavened dough is done by () to repent the dregs.

a.The leavening agent separates and releases two pre-carbon oxides.

b.Potatoes are slowly releasing carbon dioxide.

c.Fermentation of yeast (correct answer).

d.The heated gas expands.

Summary. The density of the dough will change.

When the dough is in its initial stage, it thickens. During the massive fermentation process, the gluten structure will begin to form, which helps to trap air into the dough. As the bubbles begin to ferment, the dough will not only become larger, but also lighter and fluffier.

It will lose its density and become more airy.

The density of the dough changes during the dough fermentation process.

The density of the dough will change. When the dough is in its initial stage, it thickens. During the heavy fermentation process, the gluten structure will begin to form quickly, which helps to trap air into the dough.

As the bubbles begin to ferment, the dough will not only become larger, but also lighter and fluffier. It will lose its density and become more airy.

Hope it helps.

Hello dear, happy to answer your <>

The dough without yeast will have the following changes during the making process:1The dough does not leave:

Yeast is a key ingredient that produces the fermentation action, and in the absence of yeast, the dough cannot proceed with the fermentation process. As a result, the dough without yeast does not swell and become fluffy. 2.

The dough has a hard texture: Yeast's role is to make the dough swell by breaking down the starch and sugar in the dough to create bubbles. Without yeast, the dough cannot produce bubbles, so the dough texture will be hard and not have a fluffy texture.

3.Poor dough taste: Because no yeast is added, there is no bubble diffusion inside the dough, resulting in a denser dough texture.

Compared to dough with yeast, dough without yeast will be relatively heavy and inelastic, and have a dull texture. 4.The dough volume does not increase:

The yeast is constantly producing gas through the metabolic process, which causes the dough to swell. However, without the addition of orange wax into the yeast, the dough does not undergo the process of dehydration and extrusion expansion, so the volume of the dough does not increase. It should be noted that in addition to yeast, the proportion and quality of other components in the dough will also affect the texture and texture of the dough.

Therefore, although the dough without yeast does not achieve the leavening effect, it can still be used to make some baked goods, such as cookies, pies, etc. 