In cracker production practice, cracking of biscuits is often encountered, and cracks caused by external pressure or impact of biscuits are customarily referred to as abnormal ruptures, which are generally caused by human factors, mechanical factors, etc. Caused by. The rapid cracking of biscuits and the unbalanced stress generated inside them cause cracks that exceed the strength limit of biscuits to be called natural cracks. This cracking is caused by the intrinsic factors of biscuits, and there are many influencing factors. In general, irregular ruptures can be reduced or resolved through measures such as strengthening management and improving packaging. However, the handling of natural fractures is more complicated. This is a big problem that has plagued the biscuit industry. It is the economy of some manufacturers. One of the reasons for the decline in benefits. Therefore, this paper discusses various factors that affect the quality of biscuit cracking and how to control it. First, the cracking factors of biscuits 1, cooling ambient temperature In actual production, cracking of the biscuits was found to be particularly severe at lower ambient temperatures. The study found that cracking of crackers has a significant relationship with the cooling temperature. As the temperature decreases, the cracking rate increases significantly and breaks down in a short time. In general, the impact of ambient temperature on the cracking of biscuits has two aspects. The first is the thermal shock and the second is the proliferation of moisture. The surface temperature of biscuits is as high as 180°C when baked. When cooled, the ambient temperature is lower than 15°C and the temperature difference is as high as 160°C. The biscuits are cooled rapidly and the surface moisture quickly evaporates. The internal moisture moves rapidly outwards under the influence of heat. Strong heat exchange and moisture evaporation cause strong stress inside the biscuit to change the relative positions of the solid particles inside the biscuit. This deformation increases with time. When the deformation reaches a certain degree, the binding of the biscuit itself is already Without this deformation, cracks occur in the cracker. It has been observed that cracks in biscuits often start in the middle and then extend outward until the biscuits break. Cracks can be found in the first 2 days of production; cracks can be found in 5 hours at low temperature and low humidity. 2, baking time and temperature The baking process of biscuits is generally divided into four stages: expansion, shaping, dehydration, and coloring. The dehydration phenomenon always runs through the whole baking process. The free water and adsorbed water are mainly eliminated in the early stage, and the combined water is eliminated later; the temperature of the combined water evaporation does not need to be too high, but it takes time if the mesh belt rotates too fast and the furnace temperature Too high, the moisture outside the biscuit quickly drains, and the internal moisture is not completely removed, resulting in differences in the moisture inside and outside the biscuit. The great moisture gradient rapidly changes under thermal shock and the biscuit breaks very easily. Some scholars have found that the average oven temperature is When baked at 210°C for 3 minutes, the natural cracking rate of biscuits was as high as 94.6%; for baking over 5 min, the average oven temperature was 176°C, and the cracking rate was only 2.8%. The water content of biscuits decreased with the baking time prolonged, and the cookies cracked naturally. The rate also decreases. 3, the amount of grease The study found that the self-cracking rate of biscuits increases with the increase of the amount of grease, and the self-cracking rate reaches a maximum when it reaches a certain value, and then the self-cracking rate decreases with the increase of the amount of grease until it reaches zero. With the increase of the amount of grease, the gluten quality becomes disintegrated from normal, and the toughness and elasticity decrease. In terms of taste, the finished biscuits changed from tough to crisp. During the formation of dough, glutenous proteins absorb water and swell. The amount of water absorbed can reach 150% to 200%. The more gluten is formed, the more bound water is formed, and it is difficult to remove it when baking, and it is very easy to cause uneven moisture inside and outside the biscuit. During the baking process, biscuits lose moisture and coagulate and deform until they degenerate. About 25% of the amylose in the flour is also condensed and deformed due to water dispersion. When the baking is not properly done, the phenomenon of “outside the coke is not cooked†will continue to occur during cooling. At this point, because the shape of the biscuit is basically fixed, the condensation phenomenon will produce greater stress. The dried biscuit is a brittle material lacking crack resistance. If there is no scar, it is very hard, and once it cracks, it is easy to break. Although the presence of gluten can increase the anti-cracking ability of biscuits, it is also the internal cause of biscuit cracking. When the gluten fibers are arranged in a net-like manner, the crack resistance is strong, and when the dough is rolled in the same direction as the over-ambassador gluten fibers, the self-cracking is more likely to occur. As a result of the observation, it was found that too many cracks and rolling directions are the same, that is, in the same direction as the arrangement of the gluten fibers. In summary, when the amount of oil and fat is small, the gluten is formed more and the quality is better, the anti-cracking ability of the cracker is increased, and its strength is enough to resist the stress generated inside. When the amount of fat and oil is large, although crack resistance of the biscuit is low at this time, the stress generated by itself is small, so it is not easy to cause self-cracking. Only when the amount of fat and oil is not too much and not too little, the stress generated inside the biscuit is larger, and the crack resistance of the biscuit itself is small, so it is most likely to cause self-cracking. 4, sugar consumption The cracking rate of biscuits decreased with the increase of sugar consumption, gluten quality became disintegrated with the increase of sugar content, and the viscosity decreased; on the taste, the biscuits became harder and more brittle. Due to the strong dehydration of sugar, the formation of gluten in the dough is reduced and the opportunity for internal stress is reduced, and the crack resistance of the biscuit is improved due to the gelling properties of the sugar. Therefore, the cracking rate of biscuits decreases with the increase of sugar usage. 5, the design of the mold The molds generally have pinholes and patterns. The pinholes are conducive to the discharge of bulking agent gas and water vapor. If the pinholes are designed to be too wide, the water vapor will be difficult to eliminate evenly, and the cracks will be more. If the pinholes are too dense, the gas will be eliminated too quickly. It will affect the bulkiness of the biscuits. Practice tells us that an average of one hole per 2.5 square centimeters is appropriate, and the flatness and cracking rate of biscuits are improved. Second, crack prevention and control measures crackers 1, cooling ambient temperature For biscuit cracking caused by low cooling ambient temperature, there are roughly two solutions to this problem, which is to extend the length of the cooling line as much as possible, and to appropriately increase the temperature around the cooling line to prevent temperature and humidity conditions. The mutation causes residual stress. Second, a cover can be added to the front of the cooling line and the cooling fan can be turned off to suppress the evaporation rate of moisture. It plays a positive role in preventing the biscuit from cooling too fast and avoiding cracking. 2, baking time and temperature Reasonably adjusting the temperature of the “bottom fire†and “face fire†in the oven during baking is the key to prevent cracking of cookies. Generally speaking, in the former temperature zone, the “bottom flame†temperature should be appropriately increased to reduce the “face fire†temperature, so that the cake blank carrying die can quickly warm up to ensure the uniform expansion of the cake blank; in the intermediate temperature zone, the “face fire†temperature should be appropriately increased. Respectively reduce the "bottom fire" temperature, so that both sides of the cake are in a high temperature state, in order to facilitate the evaporation of water inside the cake, in the end temperature area, can only retain part of the "surface fire" temperature, cancel the "bottom fire", use the cake blank to carry the mold The heat heats the bottom surface of the cake until baked out. 3, the amount of fat and sugar In view of cracking of biscuits caused by raw material usage, our common solution is to rationally design recipes, avoid sensitive critical points, and improve the dough-making process to ensure that dough gluten forms a network, and to ensure a reasonable rolling ratio for each roll during molding. The dough has some time after self-adjusting. 4, mold Always inspect and clean the cake carrier mold to keep the inside of the mold clean. The height of the punching pin is moderate to prevent the pinholes on the cake blank from impervious. The air permeability of the cake blank does not meet the requirements. During the baking process, the cake is kept. The carrying mold of the billet is arranged in a “person†shape, which is conducive to the flattening of the biscuit shape and the expansion of the biscuit billet. At the same time, the “human†type heat capacity is high, which is also conducive to the slow cooling of the biscuits after baking. Third, the conclusion Cracking biscuits is a comprehensive issue involving food chemistry, thermodynamics, materials science and production management. Can not be resolved from a single aspect. Practice has shown that it is necessary to comprehensively consider the above factors before the bear better inhibit cracking crackers. Disclaimer: Some articles in this website have been transferred from the Internet. If you are involved in third party legal rights, please inform this website. phone The greenhouse a filled with equipment like hydroponic, irrigation, auxiliary lighting ,temperature and humidity control and also may be automatically controlled by a computer to maximize potential growth. Auxiliary Facilities,Greenhouse Ventilation Fan,Greenhouse Fogging System,Greenhouse Movable Irrigation JIANGSU SKYPLAN GREENHOUSE TECHNOLOGY CO.,LTD , https://www.thgreenhouse.com
Hydroponics can be used to make the most use of the interior space. The relatively closed environment of a greenhouse has its own unique management requirements, compared with outdoor production. Pests and diseases, and extremes of heat and humidity, have to be controlled, and irrigation is necessary to provide water. Most greenhouses use sprinklers or drip lines. Significant inputs of heat and light may be required, particularly with winter production of warm-weather vegetables.