玉米片是世界上*普遍的谷物休闲食品。用于加工玉米片的原料选用硬质马齿型玉米，因其角质胚乳含量较高，淀粉糊化后透明度高，产品外观好。食用时，用沸水调制成玉米片冲剂。若将玉米片放进调好的汤内，可做成玉米片汤。目前我国生产的玉米片，有淡玉米片、甜玉米片和咸玉米片。淡玉米片呈棕黄色；甜玉米片呈黄褐色，咸玉米片呈黄色^[1]  。玉米含有很大的胚，玉米胚芽会影响淀粉糊化和玉米片的形态，给加工操作过程带来不便，所以生产玉米片多采用脱皮去胚后的玉米糁为原料，下面介绍两种玉米片的加工方法。

焙烤玉米片

玉米糁→加压蒸煮→干燥→调质→轧片→焙烤→调味→焙烤玉米片

(1)加压蒸煮。将提胚后粒度约为玉米粒1/3大小的玉米糁送入旋转滚筒型高压蒸煮锅中，同时加入糖和盐等调味料，再加水使玉米糁含水量达35%～45%，用174干帕的蒸汽蒸煮1～2小时，至玉米糁完全糊化。判断糊化程度达到与否可用目测观察，即玉米糁呈半透明状时便符合要求。

(2)于燥调质。蒸煮结束后，减小蒸锅压力，通过离心作用将玉米糁从网状出口清出，蒸煮过程中粘结成团的玉米糁被打散。接着将玉米糁通过传送带送入烘干机干燥，使水分降至20%左右。

(3)轧片。将玉米糁冷却至30℃～40℃后送往轧片机压成薄片，轧片机由一对不锈钢光辊组成，轧辊转速为180～200转/分钟，将玉米糁轧成0.7～1毫米的厚度。

(4)焙烤。轧好的玉米片送往烤炉焙烤，经302℃、50秒或288℃、2～3分钟焙烤，使水分降至3%以下，冷却后调味，即可得到色泽金黄、口感松脆的焙烤玉米片^[2]  。

油炸玉米片

玉米糁→酸液浸泡→中和→水洗→沥干→磨碎→成型→焙烤→过筛→油炸→调味→油炸玉米片

玉米糁用亚硫酸水浸泡16～18小时，再用石灰水中和，石灰水用量为玉米糁的0.8%左右，中和后经水洗、沥干，进入金钢砂磨磨碎成细渣，湿细渣经压制成型，成为边长约4～5厘米，厚为2～3毫米的三角形片状，进行高温快速焙烤，焙烤温度为371℃。焙烤后通过带孔钢丝传送带，筛去细碎屑，进入油锅油炸，油炸时间为1分钟。油炸后进入调味滚筒中进行调味，调味后包装即为油炸玉米片成品^[2]  。

维尔·凯斯·凯洛格（Will Keith Kellogg）发明玉米片时的工艺流程：

玉米→蒸煮→加入盐等充分揉制→造粒成型→压片→焙烤→玉米片

经过了一百多年的生产和实践，生产设备不断改进，自动化程度越来越高，流程虽然没有变化，但生产过程却有了巨大的改变。原料由开始时的玉米粒改为了玉米粉，蒸煮的方法改为了采用双螺杆挤压机连续进行，造粒成型也在挤压机上一次完成，通过预干燥后压片成型，使产品更加均匀，口感更好。很高的焙烤温度使产品的风味更加突出。的工业化设备和流水线就形成了如下的现代玉米片生产工艺：

玉米粉、糖、盐、其他营养素→混合配料→双螺杆挤压熟化→切割成型→预干燥→压片→高温焙烤→玉米片

工艺描述：

1） 配料：玉米片的配料非常重要，调味料要保证有好的口味，特别是对玉米原料的要求，直接关系到能否做出高质量玉米片产品，还有就是各种营养素的比例、含量。

2） 挤压熟化成型：玉米片的挤压熟化成型工艺是生产出高质量玉米片的关键。维尔·凯斯·凯洛格(Will Keith Kellogg）发明玉米片时的工艺玉米必须完全熟化而又不能有任何膨化，只有这样才能做出密实、硬脆、香味突出的玉米片。

3） 切割：将双螺杆挤压机挤压熟化后的物料切割成大小一致的粒状物料，物料呈半透明状。

4） 预干燥：切割成型的物料进入干燥机进行预干燥，表面经干燥后形成了一定的张力，不再互相粘连，有利于压片的顺利进行。

5） 压片：压片工艺也是玉米片生产中的关键，对压片机的要求很高，轧辊表面必须有很高的光洁度，轧辊必须恒温。

6） 高温焙烤：玉米片产品是否具有硬脆、密实的组织结构，突出的玉米特有风味，焙烤工艺至关重要，在维尔·凯斯·凯洛格（Will Keith Kellogg）发明玉米片时的工艺是用明火加热空气进行焙烤，直到，这一工艺都没有丝毫改变，现代工艺中也必须采用这一工艺，用明火直接加热空气到260℃左右，进行焙烤。

7） 经焙烤后的玉米片冷却后即为玉米片产品，也有很多的玉米片进行后工序的处理，涂糖或涂巧克力，大多是根椐市场需求来定。

Cornflakes are the most popular cereal snack food in the world.The raw materials used for processing corn flakes are preferably hard horseshoe corn, because of its high content of keratinocytes, high transparency after starch gelatinization ａnd good appearance.When eating, the corn flakes are prepared by boiling water.If you put the cornflakes into the soup, you can make the sliced corn soup.At present, the corn flakes produced in China are light corn flakes, sweet corn flakes ａnd salty corn flakes.The pale corn flakes were brown ａnd yellow.Sweet corn flakes are yellow-brown ａnd salty corn flakes are yellow [1].Corn contains a lot of embryo, corn germ can affect the starch gelatinization ａnd corn flakes form, bring inconvenience to the machining process, so the production of corn flakes with peeling to embryo grits as raw material, after the two corn flakes processing method is described below.

Baked corn flakes

Grits - grits - pressurized cooking - drying - conditioning - rolling - grilling - seasoning - grilling - grilling

(1) pressure cooking.Will be after the embryo size about corn kernels, a third the size of the grits into the rotary drum type high pressure cooking pot, add the sugar ａnd salt ａnd other seasonings, then add water to make grits water content was 35% ~ 45%, with 174 dry steam cooking 1 ~ 2 hours, to grits pasting completely.Grits can be visually observed when they are translucent.

(2) adjust the quality in dryness.After cooking, the pressure of the boiler is reduced, ａnd the grits are removed from the outlet of the mesh by centrifugal action.Grits are then fed through a conveyor belt into a dryer to dry, reducing moisture to about 20 percent.

(3) the flaking.Will grits after cooling to 30 ℃ to 40 ℃ to pressed into thin slices of flaking machine, rolling machine is composed of a pair of light stainless steel roller, roller speed is 180 ~ 180 r/min, grits rolled into the thickness of 0.7 ~ 1 mm.

(4) baked.Rolling good corn flakes to oven baked, after 302 ℃, 288 ℃, 50 seconds or baked 2 ~ 3 minutes, make the moisture below 3%, after cooling to taste, color golden, crunchy taste can be baked corn flakes [2].

Fried cornflakes

Grits [grits] are made from sour water, water, water, drain, grated, moulded, baked, sifted, Fried, seasoned ａnd Fried

Grits with sulfite soaking water 16 ~ 18 hours, reoccupy limewater neutralization, about 0.8% of the lime dosage for grits, ａnd after washing, drain, after entering the corundum bruised into fine slag, wet fine slag after pressing forming, become a length of about 4 ~ 5 cm, triangle flake for 2 ~ 3 mm thick, high temperature baking, baking temperature of 371 ℃.After roasting, the fine particles are removed through a wire conveyor belt with holes in it, ａnd then Fried in an oil pan for 1 minute.After frying, it goes into the seasoning drum for seasoning. After seasoning, it is packaged as Fried corn flakes [2].

Will Keith Kellogg invented the technology for the corn chip:

Corn - steaming - adding salt ａnd other sufficient kneading - granulation - forming - pressing - baking - cornflakes

After more than 100 years of production ａnd practice, the production equipment has been continuously improved ａnd the degree of automation has become higher ａnd higher. Although the process has not changed, the production process has changed dramatically.Raw material by the change at the beginning of the kernels for corn flour, cooking method to change in order to adopt double screw extruder for continuous, granulation in extrusion molding machine last completed, after preliminary drying pelleting forming, make the product more even ａnd taste better.The high baking temperature accentuates the flavor of the product.Advanced industrial equipment ａnd production lines have formed the following modern corn chip production process:

Corn meal, sugar, salt, ａnd other nutrients - mixed ingredients - twin-screw extrusion ａnd ripening - cutting ａnd forming - predrying - pressing - high temperature baking - cornflakes

Process description:

1) ingredients: corn flakes of ingredients is very important, seasoning to ensure have a good taste, especially the demand for corn raw material, is directly related to whether make corn chips with high quality products, as well as a variety of nutrients, the proportion of the content.

2) extrusion ａnd maturation: the extrusion ａnd maturation process of corn flakes is the key to producing high-quality corn flakes., Keith Kellogg (Will Keith Kellogg) were invented corn process corn must be fully curing ａnd cannot have any puffing, only in this way can make dense, hard brittle, aroma prominent cornflakes.

3) cutting: the extruded ａnd matured materials of the twin screw extruder are cut into granular materials of the same size, ａnd the materials are semi-transparent.

4) pre-drying: the cutting ａnd forming materials enter the dryer for pre-drying. After drying, certain tension is formed on the surface, which is no longer adhesive to each other.

5) sheet pressing: the sheet pressing process is also the key in the production of corn flakes. The requirements for the sheet pressing machine are very high.

6) high temperature baking: whether cornflakes products have hard brittle, compact structure, highlight the characteristic flavor ａnd odor of corn ａnd baking process is critical, in, Keith Kellogg (Will Keith Kellogg) were invented corn process is baked by firing air, until, the process is not the slightest change, also must use modern technology, the technology, with flame heating air directly to about 260 ℃, for baking.

7) when the baked corn flakes are cooled, they are corn flakes. There are also many corn flakes that are processed in the later process.

原创作者：济南美腾机械设备有限公司