In the baking process, whether it is bread, cakes, or biscuits, sugar is everywhere.
Today, "not too sweet" is the highest rating for desserts, and sugar has been branded unhealthy.
In fact, sugar is not unhealthy, but indulgence can be unhealthy. No matter what you indulge you will be unhealthy, as long as you grasp your desire to eat sweets, you can be happy and healthy.
Today, let's dig into the things about the reaction of sugar to Maillard!
1
The role of sugar in bread
Sugar, we commonly have: caster sugar, cottony sugar, powdered sugar, crude sugar, etc., for bread making, sugar in addition to increasing sweetness, there are many important roles:
1. Increase the sweetness of products and improve the nutritional value
One of the main roles of sugar is to give it a sweet taste.
Sweetness helps mask and balance the sour, bitter, astringent and other flavors of other ingredients in the product, which can greatly enhance the human senses.
Sugary foods quickly enter the bloodstream, meet the brain's energy needs, relieve hunger, eliminate fatigue and discomfort, and make people feel happy.
2. Adjust the fermentation rate of dough
Sugar is the main source of energy for yeast fermentation, and adding the right amount of sugar can make yeast fully play its role in the fermentation process.
In the fermentation process, yeast fermentation utilizes only simple sugars, such as glucose, fructose, etc. Disaccharides (sucrose, maltose) are too large to penetrate yeast cell membranes and cannot be directly used by yeast. Yeast decomposes sucrose in sugar into glucose and fructose through the hydrolysis of invertase enzymes, which are used as energy for fermentation.
Within a certain range, the more sugar added, the faster the fermentation rate, and the proliferation of yeast also plays a role in limiting the growth of bacteria in the dough and preventing the dough from being contaminated.
However, not the more the better, in general, the amount of sugar is 0% ~ 35%, on the contrary, too high sugar content will increase the osmotic pressure, yeast cells will be unbalanced, the rate of fermentation will be slowed down, prolong the fermentation time.
3. The carking reaction colores the dough
When the sugar is heated to a certain extent, the molecules begin to disintegrate and separate, and the chemical reaction produced is the caramelization reaction.
Experience sharing:
Caramelization reaction belongs to non-enzymatic browning in browning reaction (browning occurs without the action of enzymes, mainly caramelization reaction and Maillard reaction two types).
A series of complex reactions between reducing sugars (carbohydrates) and amino acids/proteins in food at room temperature or when heated are called the Maillard reaction.
The formation of the color of the bread surface is the result of the combination of sugar browning reaction and Maillard reaction.
Sugar after heating, molecules and molecules combine with each other, produce caramel, browning reaction, so that the surface of bread has a good color, and sugar and protein combination after high temperature, will produce Maillard reaction, the formation of brown-black macromolecular substances black black black essence or melanin, so that the bread produces a very attractive golden yellow to dark brown.
Experience sharing:
Yeast in fermentation will continue to produce acid to reduce the pH value of the dough, and in the more acidic environment, the Maillard reaction will be inhibited, the reaction rate will be reduced, so if the bread is over-fermented, the dough PH will be too low, the dough is acidic, which will make the Maillard reaction be inhibited, the reaction is not strong, so that the upper is slow.
Yeast consumes the sugar in the dough when fermenting, and if it is over-fermented, it will consume too much sugar in the dough, and it will also affect the Maillard reaction, making it slow to color.
Conversely, for bread with insufficient fermentation, yeast consumes less sugar in the dough, and the sugar content will be higher than that of normal fermented dough, so the Maillard reaction will be strong, the coloring will be too fast, and the color will be darker.
Therefore, if the dough with high sugar content is not suitable for baking at high temperatures. Conversely, dough with too little sugar content needs to be baked at high temperatures.
4. Control the nature of the dough and extend the storage time of bread
Sugar has strong water retention, and the sugar in bread can make free water into bound water, prevent dehydration and starch aging.
It can not only absorb some free water in the dough, but also easily penetrate between the protein molecules after water absorption, so that the water in the gluten protein is reduced, the degree of gluten formation will be reduced, and the dough elasticity will be weakened.
For bread with a certain sugar concentration, such as sweet bread, Danish bread and other bread products with high sugar content. The permeability of sugar can well inhibit the growth of microorganisms, reduce the spoilage caused by microorganisms on bread, and extend the storage time.
5. Improve the flavor and texture of bread
In addition to producing melanoids, the Maillard reaction produces hundreds of intermediates with different odors, including reducing ketones, aldehydes and heterocyclic compounds, which provide bread with a delicious flavor and attractive color.
Sugar is not a soft material, but sugary bread coloring quickly when baked, shortening the baking time, can retain more moisture, and make the bread soft. The texture properties of bread gum, elasticity and recovery were positively correlated with bread quality, while the texture properties such as hardness, adhesiveness and chewiness were negatively correlated with the quality of bread.
The addition of sugar in bread making reduces the hardness of bread, reduces chewiness, increases elasticity, and improves the quality of bread. On the contrary, the higher the hardness of the bread, the higher the chewing type, the worse the taste, moderate elasticity can increase the chewing resistance of bread, and too high elasticity will lead to the taste of bread and reduce quality.
6. Influence on dough water absorption rate and stirring time
At normal dosage, sugar has little effect on the water absorption rate of the dough.
The increase of sugar will cause the water absorption rate of the dough to decrease, prolong the mixing time of the dough, especially the high sugar formula (sugar content accounts for 20% ~ 25% of the flour amount), if the dough does not reduce the amount of water added or extend the dough mixing time, the dough is not stirred enough, the gluten can not be fully expanded, resulting in small bread volume and rough inside.
Experience sharing:
Because sugar needs water to dissolve in the dough, gluten formation and expansion also need water, the formation of sugar and gluten to compete for water, the more sugar, the less water the gluten absorbs, delay the formation of gluten, hinder the expansion of gluten, must increase the stirring time to fully expand the gluten, the ductility of the dough also becomes stronger, so it is important to strike a balance between ductility and elasticity.
2
Why the aroma of bread will
What fascinates humanity so much?
As can be seen earlier, one word is mentioned repeatedly: the Maillard reaction.
Maillard reaction, named after the French chemist Louis-Camille Maillard. Also known as the Maillard reaction, Maillard reaction, Mena reaction, carbonylamine reaction.
It is a non-enzymatic browning reaction widely distributed in the food industry, which refers to a series of complex reactions between reducing sugars (carbohydrates) and amino acids/proteins in food at room temperature or heating, and the result is the formation of brown-black macromolecular substances such as melanin or melanin.
In addition to producing melanoids, the reaction produces hundreds of intermediates with different odors, including reducing ketones, aldehydes and heterocyclic compounds, which provide food with a pleasant flavor and attractive color.
The reaction is a form of non-enzymatic browning, which is typically performed rapidly from about 140 to 165 °C (280 to 330 °F). At higher temperatures, caramelization and subsequent lysis become more pronounced.
In the process, hundreds of different flavor compounds are produced. These compounds in turn break down to form more new flavor compounds, and so on. Each type of food has very unique flavor compounds that form during the Maillard reaction.
Flavor scientists have been using these same compounds for years to create artificial flavors. And now our gourmet makers are also using this reaction to make different cuisines.
3
Factors influencing Maillard's reaction
Which ones are there?
The Maillard reaction has three phases: initiation, intermediate, and final.
The initial stage, also known as the colorless stage (the product is colorless and does not absorb ultraviolet light) (the product is colorless to yellow, strongly absorbs ultraviolet light) (the product has a very dark color); Intermediate stage: also known as color production stage; The final stage, also known as the color stage.
The Maillard reaction is a physicochemical reaction.
▲Experiment with 7 different proportions of sugar
# 1. Types of amino acids:
Amino acids are important substances for producing the Maillard reaction. There are twenty types of amino acids, and each amino acid produces a different flavor. Among them, His(histidine), Lys (lysine), Pro (proline) can produce the aroma of toast;
# 2. Types of sugar:
Sugar is also an essential substance in the Maillard reaction. In the Maillard reaction, the sugars involved in the reaction can be disaccharides, five-carbon sugars, and six-carbon sugars. Available disaccharides are lactose and sucrose; The five-carbon sugars are xylose, ribose and arabinose; Six carbon sugars include glucose, fructose, mannose, galactose, etc. The reaction rate of each sugar is also different.
# 3. Temperature:
Temperature is one of the most important influencing factors in the Maillard reaction. Under normal circumstances, the reaction speed of Maillard accelerates with the increase of processing temperature, and fragrance substances are mainly formed by reaction at higher temperatures.
# 4. Reaction time:
Reaction time is also an important factor in Maillard's reaction. The time of reaction it affects the nutritional content of this food. If the temperature is too high and the time is too long, not only the nutrients in the food amino acids and sugars are destroyed, but also carcinogens may be produced, and the higher the content as the processing temperature increases.
# 5. Water activity:
The strength of the Maillard reaction largely depends on the hydration of the medium, in order to achieve maximum reactivity, the food moisture content is generally required to be more than 10%, usually 15% is better. In a certain range (10~25%), the Maillard reaction rate has an upward trend with the increase of moisture, and it is difficult for Maillard reaction to occur in completely dry food.
# 6. PH value:
Generally, the Maillard reaction shows an upward trend with the increase of pH (3~10), and in the more acidic environment, the Maillard reaction will be inhibited and the reaction rate will be reduced.
# 7. Irradiation:
Irradiation can also cause Maillard to proceed, but the reaction under irradiation conditions is different from when heated. When non-reducing disaccharides and sucrose do not produce brown pigment under heating conditions, but brown substances are formed under irradiation conditions, it indicates that sucrose also appears reducing under irradiation.
Experience sharing:
At the time of irradiation, the speed of carbohydrates participating in the reaction is sucrose> fructose, arabinose, xylose > glucose, but in thermal reactions, the speed of carbohydrates participating in the reaction is valeralde> heptaldehyde delete> hexanone > disaccharides.
This may be because the energy released by irradiation breaks the glycosidic bonds, releasing carbonyl groups that further react with amino compounds.
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If someone asks, can the amount of sugar in the recipe be adjusted at will?
The answer must be No! The sugar in the recipe should not be greatly increased or decreased at will! Otherwise, it is likely that the flavor of the product will be lost, or even directly fail, and the higher the sugar content of the formula, the greater the impact of sugar on the finished product.
Experience sharing:
Some breads can have a sugar content of up to 22-35%, which increases sweetness but also affects fermentation and gluten tissue. This high-sugar bread is recommended to use high-sugar yeast, or increase the amount of yeast (about 3.5-4% of fresh yeast), reduce the amount of salt (1-1.5%), and extend the stirring time.