生产技术
早餐谷物可以通过蒸煮谷物或玉米粒的传统工艺生产。新技术的使用也使产品具有与传统产品相似或更好的特性，利用现代系统提供更大的灵活性和更少的能源消耗。其中有挤碎麦片、膨化麦片和碎麦片。很明显，最终产品是对原材料和加工的广泛研究的结果，重点还在于优化浪费和减少时间。早餐谷物市场主要包括以玉米、谷物和大米为原料的产品。传统工艺的最初阶段是在一个旋转的锅里用蒸汽蒸煮谷物，把已经洗干净的谷物与糖、小米提取物、盐和水的溶液放在一起。首先对质量进行预热，以便于内核吸收溶液。然后蒸一下。这一步所需的时间根据原料的不同而不同，当谷物不再坚硬和白垩质，而是柔软和半透明时就完成了。然后，煮熟的面团由锅内的风扇冷却，倒到传送带上，通过“卸料机”将面团分离成单一的玉米粒。 The next steps are drying, flaking and toasting.The first involves a thermal treatment at temperatures under 120°C and is aimed at eliminating enough dampness in order to make the external layer of the grit rigid so that the mass does not become mushy during the flaking process. The second step involves pressing the grit (after a quick cooling to room temperature) through two big rolling presses. This gives the grit its flake shape. Finally, toasting is the step where the excess water content is eliminated with temperatures ranging from 280°C to 320°C. Now, as an alternative to traditional production, cereals are produced with extrusion technology. In this case, the thermal treatment is no longer applied to the entire grit, but to the flour (generally a mix). Other than the classic flake, breakfast cereals can have variable shapes and sizes (rice kernels, balls, etc.). The use of extrusion (widely utilized in chemical and petrochemical industries) on food products was not an easy task. It involved an extensive amount of research into the rheological behaviours of the mix of solid elements (flours, sugar, cocoa, salt, vitamins and other additives in powder form) and liquids (various syrups water, honey, and other fluid ingredients) during the treatment. Nonetheless, once that the laws of physics and chemistry underlying the process were understood, the use of extrusion has led to reducing operating costs due to the higher level of energy efficiency. Furthermore, it has been possible to combine the cooking, mixing, and separation steps, resulting in a simplified production process and guaranteeing a product with more uniform characteristics and reduced waste. Inside the extrusion system, processing takes place under high pressure and temperature conditions, in order to gelatinze the starch and denature the protein. During hydrolysis, the starch loses its crystalline structure and takes on the characteristics of a gel. This transformation breaks down the molecules, making them more digestible. The higher the level of gelatinization, the easier the starch can be transformed into glucose by the alpha amylase enzymes, causing the glycemic index to increase. Researchers, in response to consumer market needs for a healthy and balanced diet, have eliminated this problem by putting flours made from non-traditional cereals into the base mixture, such as amaranth, rye, millet, etc, which offer higher fibre, and limit the hydrolysis of the starch, reducing the glycemic index. With the addition of these flours, the product also maintains an expansion factor similar to the original. As to proteins, even their denaturation has a positive effect on the digestibility since it increases the food’s sensibility to digestive enzymes.
形成麸质的作用也很重要，因为这为最终产品提供弹性和可塑性。即使在生产市场上高度要求的无麸质食物中，挤出过程也非常有用。事实上，通过利用由于淀粉的预凝胶化而利用混合物的凝聚力和弹性的增加，可以获得类似于经典面粉的早餐谷物。挤出还导致植物（特别是麸皮）中存在的植物植物的降解，其限制钙和锌等必需矿物质的可用性以及其他抗营养因子的总体或部分灭活。高处理温度也在加工过程中消毒食物。在挤出系统的出口处，通常存在具有曲线和形状的滤网的屏幕，以及用于模拟砂砾的刀具。在薄片的情况下，该过程的后续步骤与传统方法几乎相同（仅在时间和热处理温度下变化）。另一方面，其他形状的谷物直接从第一个干燥步骤到敬酒。另一种谷物生产技术用于膨化谷物。该过程直接与谷物（主要是水稻，但现在具有新的生产方法，其他谷物也是可能的）或来自挤压砂砾。 In both cases the raw material is inserted into a hermetically sealed chamber inside either a single or multiple-shotgun machine. The system is heated and vapour is introduced into the machine in order to increase the pressure to a pre-defined level. When the chamber is then opened, a sudden drop in pressure occurs and this causes the puffing of the cereal. A production line like this can be accompanied with coating machines and other systems to produce vitamin and mineral enriched cereals, and chocolate or honey coated cereals. Another category of breakfast cereals is the shredded types, which are bars that are produced from the grain. Today extrusion is used for producing shredded cereals. The grain, pre-cooked and partially dried, or the extruded mass, is conveyed through rollers, one with a smooth surface and the other grooved. The result is a lattice of ground cereals that is then placed on a conveyor belt and sent through a cutting system that divides the lattice and presses is into a single layer. The bars formed like this are then baked in an oven. This type of product can also be filled with nuts, dried fruit, chocolate or marmalade. The realm of breakfast cereals has evolved over the years from a simple product made from raw material and traditional processes, to a multitude of healthy and tasty variants, which have been the result of research and technological advances.
参考书目
•Varacca A.，Sckai P.，Diglerenziazione del Prodotto E Coldentizione Tra Marche Nel Mercato dei Celieali da Colazione。Agriagionieuropa Anno 8 N°31，DIC。2012年
•Fast R.B，即食谷物的制造技术，在早餐谷物和他们是如何制作的，Fast R.B和考德威尔e.f.，编辑。美国谷物化学家协会，1990
•蒋炳彦，淀粉在挤出产品中的糊化作用，食品化学，54(3):436-443
由Massimiliano Binaschi，Roberta Dordoni
葡萄酒和农业食品工程研究所，Università圣城，皮亚琴察
