Biscuit Production Line Production Principle
In order to make shortening dough, firstly, fat, sugar, water and other auxiliary materials are put into the mixing machine to be fully mixed and emulsified into a uniform emulsion, and then finally wheat flour is added, so that the water absorption and swelling of wheat flour in the presence of a certain concentration of molasses and fat is restricted. It not only restricts the water absorption of gluten proteins and controls the rise of the dough, but also shortens the modulation time of the dough.
The main purpose of making shortening dough is to reduce the hydration and control the formation of gluten; to avoid the elasticity and strength of the dough increasing due to the formation of a large number of gluten, and plasticity decreasing, causing the toughness and deformation of the cake biscuits; to prevent the film formed by gluten from causing the surface of the cake biscuits to swell and blisters during the baking process.

Biscuit Production Line Process Essentials
Modulation
To produce good quality shortbread Biscuits. Dough making is one of the most critical processes. Shortening dough requires good plasticity and adhesion. Very little elongation and elasticity. The dough should be able to hold together without falling apart during molding. No sticking to the mold. The molded Biscuit blank should have good pattern and pattern retention. Not deformed during baking. Moderate spreading. The finished product has a clear pattern. The temperature of shortbread Biscuit dough after modulation is close to or below room temperature. Often referred to as cold flour.
To minimize gluten formation. Shortbread dough is usually prepared in a two-step process. First, all ingredients except flour are placed in a special mixer. Mix at a slow speed for a few minutes. The effect is to dissolve as much sugar as possible with a limited amount of water. Evenly disperses and dissolves the milk powder, chemical bulking agents and solid flavors and fragrances. Forms a homogeneous emulsion. Sometimes it is necessary to add monoglycerides or phospholipids to the recipe to help form a homogeneous emulsion system. The flour is then added to the mix. On the premise of ensuring that the various raw and auxiliary ingredients are mixed evenly. Minimize the time required for the second stage of modulation. The two-step dough modulation method utilizes the anti-gluten hydration of sugar and fats to inhibit gluten formation. Sugar is dissolved to form a solution with a certain concentration. In this solution water molecules are bound by sugar molecules. The hydration with the hydrophilic groups of gluten proteins is reduced. This reduces the formation of gluten. Dispersed oils and fats are mixed with flour. The grease is able to adsorb on the surface of the flour particles. Forming a layer of oil film. It hinders the contact of water molecules with gluten proteins and the expansion of the gluten network.
Shortening dough modulation requirements are very strict. A little too much water or a little too long mixing time may cause the quality of the dough to deteriorate. Therefore, it is very important to correctly judge the focus of dough preparation. The following points should be noted when making short dough.
The amount of water and mixing time: the specific amount of water in actual production should be based on the protein content of flour and Biscuit recipes. Under normal circumstances, adding more water, softer dough is easy to form gluten. Therefore, the mixing time should be shorter. On the contrary, the dough with less water should be mixed for a longer period of time, otherwise the adhesion of the dough is poor. Poor dough molding performance. In general, the water content of shortening dough in 16% to 18% is appropriate.
② modulation temperature of the dough: generally through the water temperature to adjust the temperature of the mixing powder. Pastry dough mixing temperature is generally controlled at 22 ~ 28 ℃. But for the oil content of the dough if the temperature is too low. It will make the dough produce a large viscosity. Not conducive to operation. On the contrary. If the dough temperature is too high. And will make the dough gluten. Cause shrinkage and deformation. Therefore, for the dough with little fat content. The temperature is controlled below 30℃. For dough with high oil content. The temperature is generally controlled between 22 and 26 ℃, because the high oil content reduces the viscosity of the dough and the binding force of the crust. Adverse effects on operation and Biscuit quality.

(iii) Resting: If insufficient gluten is formed during mixing. Proper resting is a remedy. Because during resting, hydration of gluten proteins proceeds slowly. This reduces the cohesion of the dough. Increased elasticity. But if resting is excessive. More water is absorbed by gluten proteins and starch. The dough becomes dry and hard. The adhesive force decreases. The organization is loose and cannot be manipulated.
Forming
Theoretically, the forming of shortening Biscuits can be done by roll stamp forming, wire cut forming, extrusion forming and roll cut forming after roll pressing. However, due to the high proportion of oil and sugar in the shortening dough. The most used in actual production is still roll printing molding. The modulated shortening dough is added to the feeding hopper of the roll printing molding machine. Under the carrying and squeezing of the feeding trough roller. The material enters into the mold of the mold roller and is compacted. A scraper close to the surface of the mold roll scrapes away the material protruding outside the mold. The bottom surface of the Biscuit blank is formed more neatly. With further downward rotation of the mold roll. The Biscuit blanks come into contact with the horizontally running canvas conveyor belt below. It is released from the mold by the rubber demolding rollers. It is transported via the canvas conveyor belt to the mesh steel conveyor belt for baking in the oven.
During the roll stamp molding process. The position of the separating doctor blade affects the quality of the Biscuit blank. When the doctor blade is positioned high, the material protruding outside the mold cannot be completely removed. As a result, the quality of a single Biscuit blank increases; when the position of the cutter blade is low, the quality of the Biscuit blank decreases. The position of the blade of the scraper is 2~5mm below the center line of the mold roll.
For smooth release of Biscuit blanks from the mold roll. A good balance should be established between the adhesion of the dough and the adhesion of the canvas conveyor belt and the pressure of the rubber mold release roller. The adhesion of the canvas conveyor belt is too poor. The Biscuit blanks will not be able to stick to the conveyor belt. This makes mold release difficult; if the adhesion of the dough is too poor. When the Biscuit blank is not in contact with the canvas conveyor belt. Under the action of its own gravity it comes out from the mold. Resulting in deformation of the Biscuit blank. Too soft pastry dough will form solid lumps. Causes underfeeding. Difficulty in removing the mold. The dough is too soft, sometimes the scraper can not scrape off the excess crumbs on the surface of the Biscuit blank. This causes the phenomenon of trailing edge. Affect the appearance of the Biscuit and the subsequent finishing and packaging. If the dough is too hard. The same will make the mold is not strong. Cause mold release difficulties or defects. Finished Biscuits have cracks on the surface. Crushing rate increases. The size of the pressure of the rubber demolding roller also has an impact on the demolding quality of the Biscuit blank. If the pressure is too small, there will be sticky roller phenomenon; if the pressure is too large, it will make the thickness of the Biscuit blank uneven. Even deformation. Under the premise of making Biscuits unmolded smoothly. Try to reduce the pressure of the demolding roller.

Baking and Cooling
Since shortbread Biscuit recipes contain more oil and sugar. There is less binding within the dough. Therefore, the water in the dough evaporates easily. Therefore, the baking of shortbread Biscuits often use “higher temperature, shorter baking time” baking process. Billet into the oven. Expansion and shaping stage requires high temperatures of the bottom and surface fire. So that the billet quickly solidified. Prevent too much fat in the formula due to the “oil stall” phenomenon. After this stage, the baking temperature should be gradually reduced. Because the crisp Biscuit formula generally contains more sugar and milk powder. So the baking temperature in the back area must be lower. Prevent the surface from excessive coloring. The actual production can be based on the product formula, the size of the Biscuit blank, the degree of softness and hardness to choose the appropriate baking temperature. Generally speaking, the temperature of the front area of the oven is 250-280 ℃, the temperature of the middle area is 220-240 ℃, and the temperature of the back area is 180-200 ℃. At this baking temperature, the baking time is 5~6min.
The crispy dough with great fluidity during baking must be conveyed on a smooth mild steel conveyor belt. The products with relatively low oil and sugar content are mainly baked on mild steel mesh belt. The heat transfer speed of the mesh belt is good. So the baking is faster. But the dough tends to get stuck in the mesh. This can cause serious Biscuit breakage problems at the end of the oven and can contaminate the mesh belt. Therefore, after the Biscuit has continuously passed through the oven. When it is unloaded from the conveyor belt its underside will show dark, burnt crushed particles.
Biscuit Biscuit blanks in the baking process “spread” is the most common problems encountered in production. Excessive spreading not only affects the appearance of the Biscuit. And will increase the Biscuit finishing and packaging of the broken rate. There are many factors affecting the spread of Biscuits during baking. The factors that increase and decrease the spread are described here. Factors that increase spread include coarser flour particles. A shorter second stage of mixing after the addition of flour. Smaller average particle size of sugar. Higher amount of crystallized sugar. Higher amount of fat. Soft dough due to high temperatures. Higher amount of bulking agent used. Biscuit blank mass too large. Oven conveyor belt oiled. Biscuits loaded on a cold oven belt and low temperatures in the front area of the oven. Factors that reduce spread include high water absorption of the flour. Overmixing of the dough. Low sugar content and large average particle size. Low fat content. Low dough temperatures. Small mass of Biscuit blanks. Oven with dusting. High oven temperature. Fast baking, etc. Corresponding adjustments can be made in production practice according to the specific situation.
Due to the molten nature of sugar. Biscuit blanks are soft when they first leave the oven. Before finishing and packaging. It must be thoroughly cooled. The method adopted can extend the cooling conveyor belt of the Biscuit. The length of the cooling conveyor belt is generally more than 1.5 times the length of the oven. But the cooling belt is too long. It is not economical and takes up space. Forced cooling of the Biscuit blanks can also be carried out by blowing air and other means. The suitable cooling conditions are 30 to 40 ℃. The relative humidity is 70% to 80%.