Effect of different extrusion temperatures and moisture content on lipoxygenase inactivation and protein solubility in soybeans
Additional Document Info
Inactivation of lipoxygenase-1, -2, and -3 and changes in protein dispersibility index (PDI) during extrusion of soybeans at different temperatures and moisture levels were studied. Soybeans were extruded at six different temperatures, ranging from 77 to 121 C, with or without holding for 30 min immediately after extrusion. Inactivation by extrusion was in the order of lipoxygenase-2 > -1 > -3. Holding for 30 min immediately after extrusion had a significant (p 0.05) effect on inactivation of lipoxygenase-3. Essentially 100% inactivation of all three lipoxygenase enzymes in extruded soybeans resulted with a PDI of about 22. Extrusion of soybeans with different moisture contents showed a rapid decrease in PDI from 68.4 to 24.2 as soybean moisture content increased from 9.2% to 16.3%.