Table des matières
A biscuit is a baked treat that is commonly consumed by many people. In order to make a biscuit, free water from the dough must be removed from it. Higher temperatures, up to 130degC, allow water in solution to be evaporated. The application of heat to a dough piece will always cause moisture loss, depending on the temperature, the method of heat transfer, and humidity of the oven.
Biscuit production lines are a highly automated process for making biscuits. The factory uses a recipe to make these biscuits. The ingredients are mixed and then molded into the biscuit. The biscuits are then baked in ovens between 160°C and 1800°C to develop the structure and colour. Once baked, the biscuits are passed to cooling conveyors to cool completely. After cooling, they are packed in different types of packaging. Primary packs are usually placed into cartons. Secondary packing is done through a vacuum packer.
Wheat flour contains the protein amylose. These molecules help to form a gel and give crackers their characteristic flaky texture. The remaining ingredients are sugar and fat. Fat is an essential ingredient for soft biscuits, as it imparts taste and contributes to the biscuit’s texture. Other ingredients that can affect the texture include ammonium bicarbonate and sodium bicarbonate. These substances enhance the volume of the dough and give it a richer flavor.
The baking process of biscuits in factories is usually done by baking the biscuits in various chambers, called zones, in the oven. Each zone is an independent oven and a large plant will have more than one zone. In a conventional oven, the biscuits are transported in a mild steel continental wire mesh. The biscuits rise, puff, and become golden brown or dark chocolate in colour, according to the type of biscuit.
Water is used as a solvent and helps form gluten. Sugar is also used to impart color and flavor to biscuits. Fat is another essential ingredient, particularly in soft biscuits. Another important ingredient in biscuits is ammonium bicarbonate. This agent is added to the dough to increase its volume and improve its flavor. After this process, the biscuits are ready to be packaged. In factories, biscuits are packaged in various types of packaging.
A large percentage of biscuits are bought on impulse. This means that packaging must be appealing to the consumer as well as sufficiently descriptive of the contents. Moreover, legislation is becoming increasingly stricter, requiring manufacturers to provide more information. In many markets, “sell by” and “best before” dates are compulsory, to give consumers peace of mind that their biscuits are safe to consume. However, the packaging must not detract from the attractive design.
Today, automated packaging systems for biscuits must be flexible. These systems should be able to accommodate changes in product characteristics and consumer demands without compromising seal integrity. Flexible film systems, such as those from ULMA Packaging Systems AG, are particularly beneficial to biscuit manufacturers, as they allow for quick changes in product characteristics and packaging methods with very little downtime. The company offers different packaging system solutions to meet the needs of biscuit manufacturers, including primary and secondary packaging systems as well as fully automated loading systems.
During the baking process, biscuits undergo three main changes. The structure and texture of biscuits develops in the first half of the oven. Moisture content decreases, and the surface begins to brown. During the baking process, three processes contribute to the colour of biscuits: caramelisation, dextrinisation, and the Maillard reaction. These reactions require high temperatures, and they are carried out after the biscuits have reached the right moisture content and structure.
Carmine is a natural substance, but its finite supply means that it is not possible to boost production. In 2013, Peru exported 531 tonnes of carmine, generating $22 million. Companies that use carmine to colour biscuits, such as Premier Foods, which produces Mr Kipling cakes and Bachelor soups, are trying to find alternatives. The production process of these products may become more expensive, as different countries have different laws on food colours.
Gelatinisation of starch
Biscuits have a tendency to be soft and crumbly due to the high concentration of fat and sugar. The addition of fat or sugars to the dough delays its gelatinisation. Besides, fats contain triglycerides, fatty acids, and surfactants. Consequently, high-fat and sugar recipes produce biscuits with low gel viscosity and short and soft texture.
Various tests have been conducted to determine the effect of protein and starch on the biscuit’s quality. Low protein and N input wheat is associated with low yield. Increasing the starch content in the flour significantly reduces the protein content and increases the gelatinisation enthalpy. Furthermore, the viscosity parameters are negatively correlated with the farinograph quality number, dough stability time, and sucrose solubility ratio. Biscuits containing added starch had a better sensory score than those with lower protein content.