steam flake corn for animal nutrition

Specifications

Steam flaked corn, the corn starch gelatinization, pasting degree can be on the same level (about 30%-40%) on the basis of the 30% increase, reaching 60% to 70%, combined with destruction and starch of hydrogen bonds, the starch granules are released from the protein. The molecular structure of starch is also changed, from the original there are rules of starch crystallization, structure of a- starch molecule structure, easy to accept the role of the enzyme, the starch is water-soluble, improve the animal body great absorption of energy and protein starch corn digestibility increased from 70% to 99% and above can achieve almost the whole digestive: at the same time a change in protein structure from natural the final fragrance palatability and digestibility increased defecation volume reduction.

1.1 steam flaking

The general process of steam flaked: raw material

→ impurity → → → → modulation steam heating pressing drying and cooling. The specific method is to remove the stones mixed in raw materials, metal impurities such as water and surface active agent (modulator) modulation, general 8%~10% 12~18 h water, making water infiltration

The corn in the corn; and then input stainless steel steam inside a vertical, by 100~110 °C steam treatment 40~60 min

Finally, the specific density; the expectation of the modulation and corn mill steam treated with large roll two preheating (usually 309~386 g/l) corn flakes, corn flakes density with the degree of processing (extrusion pressure) increases

(Preston, 1999) [2]. Corn flakes can be fed directly or to be the "cooling and drying" (lost some water) after feeding.

Zinn (1997) [3] compared the digestibility and feeding value of flaked corn fresh and dried, discovery does not affect the feeding effect.

1.2

Process parameters

Effect of steam flaked quality depends on the whole process of heat and force, that is to say, different process parameters on its nutritional value.

Have a great impact, the main factors of steam treatment time, extrusion pressure.

1.2.1

Steam processing time

Modulation and steam treatment to make corn reached a certain moisture content of corn steam flaking process, and in a certain temperature of corn starch

Moist heat treatment make it paste.

The reported research on steam time rarely, theoretically extending steam time can make the corn starch granules to fully absorb the moisture, when the saturated state, will reach a plateau. Zinn (1990)

[4] the 3 time periods (34, 47, 67 min) studied, the conclusion is: 34 min is the digestive tract starch digestion rate can reach the best (99.5%) time, extend the time and can not improve the nutritional value of steam flaked corn. The time of steam treatment of foreign 40~60 min is usually used in practical production.

1.2.2

The extrusion pressure

Roll through the modulation and steam treated corn through two preheating pressed into corn flakes of certain density, the two roll is a fixed roller, a movable roller.