Effect of extrusion temperature on free gossypol and feedstuffs in cottonseed meal

The effect of extrusion temperatures( 90,100,110,120 and 130℃) on free gossypol and feedstuffs were studied in cottonseed meal.The results showed that the best temperature for free gossypol degradation was 120℃,the degradation rate of free gossypol did not increase with the increase of temperature above 120℃.The nitrogen solvable index( NSI) reduced quickly with the increase of extrusion temperature,and the contents of crude fiber,available lysine and total lysine were significantly decreased in cottonseed meal,but the highest contents of total amino acids( AA) and essential amino acid( EAA) were obtained at the extrusion temperature of 120℃.The highest contents of branched- chain amino acids( BCAAs) were also observed in the 120℃ sample. In conclusion,a extrusion temperature of 120℃ was preferred for lower free gossypol and higher nutritional value of cottonseed meal.