Verhalten von Sojasorten mit unterschiedlicher Trypsininhibtoraktivität bei der Aufbereitung

The organic acreage of soybeans in Germany is growing steadily the last five years. It is mainly used as protein feedstuff for poultry and pigs. To eleminate antinutrional factors in soybeans before feeding, a very energy intensive processing is required. The aim of the study was to find out if varieties with less trypsin inhibitor activity (TIA) require less energy input. For that a hydro-thermal soybean processing trial was conducted with a combination of autoclav and expander. Four soybean varieties varying in the TIA were used in 20 different process variations. To classify the feedstuff quality the protein solubility in KOH and the TIA were measured. The results show that TIA reduces quite fast according to the energy input. A heating process with 100°C for ten minutes and a temperature of 125°C at the expander reduced even the variety with the highest TIA sufficiently. Lower energy inputs were sufficient for the varieties with lower TIA