Effect of processing of soybeans on release of free fatty acids and subsequent effects upon fiber digestibilities

摘要

Two in vitro experiments were conductedto determine the rates of lipolysisand biohydrogenation of fat from raw orprocessed soybeans and to examine subsequenteffects upon fiber digestibilities.In experiment 1, substrates containingsoy oil; raw soybeans; extruded soybeans;and soybeans roasted at 270,295,or 325 °F were incubated with ruminalcontents for 2, 4, 6, 12, or 24 hr, andrelease of free fatty acids was measured.The fatty acids released from substratescontaining soy oil, extruded soybeans,and raw or roasted soybeans reachedmaximums at 4, 6, and 12 hr incubations,respectively. Fatty acids in roastedsoybeans were subjected to less biohydrogenationthan those in raw or extrudedsoybeans, suggesting that fattyacids of roasted soybeans are protectedpartially from ruminal bacteria. At allincubation times, the substrates containingsoy oil or extruded soybeans hadlower and those containing roasted soybeanshad higher fiber digestibilities.