Production process of puffed snack food

Types and principles of puffed food

Puffed food, also known abroad as extruded food, explosive food, light food, etc., is a new type of food developed internationally in recent years. It uses grains, beans, potatoes, vegetables, etc. as raw materials, and is processed by puffing equipment to produce a wide variety of food with exquisite appearance, rich nutrition, crispy and delicious food. Therefore, a large category of food has been uniquely formed.

Due to the simple structure, easy operation, low investment in equipment and quick returns, the equipment for producing this puffed food has developed very rapidly and has shown great vitality.

Due to the difference in use and Jinan Linyang puffing machinery and equipment, puffed food has the following three types: one is to use an extruder extruder to produce small food with corn and potatoes as raw materials; the other is to use an extruder extruder to Plant protein is used as raw material to produce tissue protein food (vegetable meat); the third is to use grains, beans or potatoes as raw materials, which are made into staple food after puffing. In addition to trial production of indirect heating extruder, it also trial produced a variety of puffed food with refined grain puffing powder.

type

1. Staple food: biscuits, bread, steamed bread, pancakes, etc.

2. Camellia oleifera: puffed noodle tea.

3. Military food: compressed biscuits.

4. Pastries: peach cake, oven fruit, eight pieces, pastry cakes, moon cakes, printed cakes, egg rolls, etc.

5. Small food: rice flower candy, cold cake, etc.

6. Cold food: filling material for sorbet and popsicle.

Among the above-mentioned foods, some varieties, such as puffed noodle tea, printed cakes, compressed biscuits, etc., are all made of puffed coarse grains; some varieties only incorporate a certain proportion of puffed coarse grains.

Although puffing technology belongs to physical processing technology, it has its own characteristics. Puffing can not only change the shape and state of the raw material, but also change the molecular structure and properties of the raw material, and form some new substances.

Principle When the grain is placed in the extruder, with the heating and pressurization, the water in the grain is overheated, and the grain itself becomes soft. When the extruder cover is opened when it reaches a certain high pressure, the high pressure rapidly At this time, the superheated water in the grains will be vaporized in an instant and a strong explosion will occur, and the water molecules can expand about 2,000 times. The internal molecular structure of the grain is broken, and the insoluble long-chain starch is shortened into water-soluble short-chain starch, dextrin and sugar, so the insoluble substances in the puffed food are reduced and the water-soluble substances are increased. 

See the table below for details:

Change table of water extract in food before and after puffing (%)

After puffing, in addition to the increase of water-soluble substances, a part of starch becomes dextrin and sugar. The puffing process changes the material state and properties of the raw materials, and produces new substances, that is to say, the use of puffing as a physical means causes the chemical properties of the products to change. This phenomenon presents a new topic for the theoretical study of food processing. .

The process of decomposing starch in food into dextrin and sugar generally occurs in people's digestive organs, that is, when people eat food into the mouth, with the help of the action of amylase in saliva, the starch can be cracked and become Dextrin, maltose, and finally glucose are absorbed by the body. The puffing technology plays the role of amylase, that is, before the food enters the oral cavity, the starch is cracked. In this sense, the puffing equipment is equivalent to prolonging the digestive organs of people. This increases the human body's digestion process of food and improves the digestion and absorption rate of puffed food. Therefore, it can be considered that puffing technology is a very scientific and ideal food processing technology.

Another feature of puffing technology is that it can make starch completely alpha. In the past, thermal processing techniques such as baking and cooking, which have matured food, can also make the raw starch of food, ie, β starch, into α starch, which is called α-starch. However, after these products are placed for a period of time, the alpha starch that has been expanded shrinks back to beta starch, which is the so-called "regeneration" or "aging". This is a common phenomenon in all starchy foods. After these foods are "aged", the body becomes hard, the taste becomes worse, and the digestibility decreases. This is due to incomplete starch alphaization.

The puffing technology can completely α-starch the starch, and the α-starch that has become α-starch cannot be restored to β-starch after being placed, so the food maintains softness, good flavor and high digestibility, which is the advantage of puffing technology over other physical processing. Another feature of the method, it opens up a new field of processing for fine grains and fine grains.

advantage

1. Improve the taste and taste: After the coarse grains are expanded, the coarse and hard tissue structure is destroyed, and the coarse grains can no longer be seen, and the taste of coarse grains cannot be eaten. The taste is soft, and the taste is improved and delicious.

2. Convenient to eat: After puffing, coarse grains have become cooked food, which can be directly washed with boiling water, or made into compressed food, or can be made into various kinds of food after a little processing. Eating between meals and saving time. As long as the food department or factories, mines, enterprises, institutions, and schools supply puffed powder, it can be processed and prepared in the family or collective canteen to become a veritable convenience food.

3. The preservation rate and digestibility of nutrients are high; the preservation rate of nutrients in the puffing process is shown in Tables 1-3. From the data in the table, the preservation rate and digestibility of nutrients in puffed food are relatively high, which means that the puffing process has no effect on the nutrition of the food, and its digestibility is higher than that of the unpuffed food.

4. Easy to store: After the grain is puffed, it is equivalent to a high-temperature sterilization, and the moisture content of the puffed powder is reduced to less than 10%. Such low moisture limits the growth of insects and mildew and strengthens their stability in storage. , suitable for long-term storage, and suitable for making military rations for combat readiness to improve its edible quality.

5. The price is cheap: using the indirect heating extruder, after each kilogram of corn is processed into puffed powder, the processing fee is about 6 cents, which means that the price of each kilogram of puffed corn meal is 2.6 cents. In our country, the monthly expenditure of each local worker only increases by 600 yuan per person based on 10 kilograms of coarse grains, which is what people can afford financially. If a continuous automatic extruder is developed in the future, the processing cost can be further reduced.

Established in 1996, DAYI has been the professional manufacturer and the model company for advanced and high efficient extrusion food machinery in this field. DAYI Company congregates an expert team with twenty-year experiences in this extrusion machine industry, not only working hard to constantly researching extrusion technology, but also exploring food processes in order to benefit our clients producing creative food.