The disadvantage of extrusion feed
1 vitamin loss.Temperature, pressure, friction and water would lead to the loss of vitamins.In expanded feed, VA, VD, folic acid loss 11%, single sulfur ammonium nitrate and ammonium sulphate hydrochloride, the loss rate are 11% and 17% respectively, vitamin k and VC loss rate of 50%, and also in hard pellet feed loss is halved
2 the loss of enzyme preparation.The optimum temperature for enzyme in 35 to 40 ℃, the highest do not exceed 50 ℃.But expanded in the process of granulating temperature of 120-120 ℃, accompanied by high humidity (feed in high water activity), and high pressure (altering the space multidimensional structure of enzyme protein degeneration), under such circumstances, most of the activity of enzyme preparation will be wiped out.Untreated, according to the Coman glucanase after 70 ℃ granulating survival rate is only 10% in the feed;Processed glucanase on material temperature is 75 ℃ the sort of 30 s, the survival rate was 64%, and then through 90 ℃ granulating the survival rate is only 19%, phytase by 70-90 ℃ after granulating vitality decline in more than 50%. 
The loss of 3 microbial preparation.At present, feed more microbial agents are mainly used in lactic acid bacteria, yeast, bacillus, streptococcus, etc., these microbes preparation is particularly sensitive to temperature, when the puffing granulating temperature exceeds 85 ℃ will lost all its activity. 
4 the loss of protein and amino acids.Puffing machine high temperature to make part of the raw materials in the process of reducing sugar and free amino acids in maillard reaction, reduces the utilization of some proteins.In addition, the protein in alkaline conditions by high temperature can form lai amino alanine, excessive heat, especially in the case of high pH value, can make the part with amino acid racemization and produce D - amino acids, all these make the protein digestion rate significantly decreased.Heating is the most vulnerable to the loss of lysine, followed by arginine and histidine
Jinan Sunward Machinery Co.,Ltd is a professional Puffing machine manufacturer. Our company could also supply many other equipments&parts including puffed food processing line, Ornamental fish feed processing line, textured soy protein processing line, pet food processing line, floating fish feed processing line, puffed feed processing line, nutritional rice processing line, corn flakes processing line, Denatured starch processing line, core filling food processing line, puffed leisure food processing line, Fried puffed food processing line, Kurkure food processing line, breakfast cereal processing line, puffed nutritional powder processing line, bread crumbs processing line and so on.