Karr-Lilienthal Lisa K, Bauer Laura L, Utterback Pam L, Zinn Krista E, Frazier Rodney L, Parsons Carl M, Fahey George C
Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
J Agric Food Chem. 2006 Oct 18;54(21):8108-14. doi: 10.1021/jf061425t.
This research examined variation in chemical composition and nutrient quality of soybeans (SBs) and soybean meals (SBMs) produced at seven commercial extruder/expeller plants in the United States (experiment 1), as well as differences in amino acid digestibilities when roosters were fed SBMs extruded at 121, 135, 150, or 160 degrees C at a U.S. pilot processing plant (experiment 2). In experiment 1, limited variation existed in the composition of SBs arriving at the plants, whereas substantial differences were noted in amino acid composition and protein quality of the resultant SBMs. In experiment 2, the SBMs extruded at 121 and 135 degrees C were underprocessed as noted by high urease activities and lower amino acid digestibilities. Soybean meals extruded at 150 and 160 degrees C resulted in higher amino acid digestibilities and lower urease activities, indicating adequate processing. Large variation exists in the nutritional quality of extruder/expeller SBMs currently in the marketplace. Optimal processing temperatures should be >135 degrees C, and temperatures as high as 165 degrees C do not result in overprocessing.
本研究考察了美国七家商业挤压机/螺旋压榨机工厂生产的大豆（SBs）和豆粕（SBMs）的化学成分和营养质量差异（实验1），以及在美国一家中试加工厂用121、135、150或160摄氏度挤压的豆粕饲喂公鸡时氨基酸消化率的差异（实验2）。在实验1中，运抵工厂的大豆成分变化有限，而所得豆粕的氨基酸组成和蛋白质质量存在显著差异。在实验2中，121和135摄氏度挤压的豆粕加工不足，表现为脲酶活性高和氨基酸消化率低。150和160摄氏度挤压的豆粕氨基酸消化率较高，脲酶活性较低，表明加工充分。目前市场上的挤压机/螺旋压榨机豆粕营养质量差异很大。最佳加工温度应>135摄氏度，高达165摄氏度的温度不会导致过度加工。
