ENVT, UMR1289 Tissus Animaux Nutrition Digestion Ecosystème et Métabolisme, F-31076 Toulouse Cedex 3, France.
J Dairy Sci. 2010 Feb;93(2):711-22. doi: 10.3168/jds.2009-2534.
Sunflower oil heated at 110 or 150 degrees C for 1, 3, or 6h was incubated with ruminal content in order to investigate the effects of temperature and duration of heating of oil on the ruminal biohydrogenation of linoleic acid in vitro. When increased, these 2 parameters acted together to decrease the disappearance of linoleic acid in the media by inhibiting the isomerization of linoleic acid, which led to a decrease in conjugated linoleic acids and trans-C18:1 production. Nevertheless, trans-10 isomer production increased with heating temperature, suggesting an activation of Delta(9)-isomerization, whereas trans-11 isomer production decreased, traducing an inhibition of Delta(12)-isomerization. The amount of peroxides generated during heating was correlated with the proportions of biohydrogenation intermediates so that they might explain, at least in part, the observed effects. The effects of heating temperature and duration on ruminal bacteria community was assessed using capillary electrophoresis single-strand conformation polymorphism. Ruminal bacterial population significantly differed according to heating temperature, but was not affected by heating duration. Heating of fat affected ruminal biohydrogenation, at least in part because of oxidative products generated during heating, by altering enzymatic reactions and bacterial population.
葵花籽油在 110 或 150°C 下加热 1、3 或 6 小时，然后与瘤胃内容物一起孵育，以研究油的加热温度和持续时间对体外亚油酸瘤胃生物氢化的影响。这两个参数增加时，共同作用通过抑制亚油酸的异构化来降低介质中亚油酸的消失率，从而导致共轭亚油酸和反式 C18:1 的产生减少。然而，随着加热温度的升高，反式-10 异构体的产量增加，表明Δ(9)-异构化的激活，而反式-11 异构体的产量减少，表明Δ(12)-异构化的抑制。加热过程中产生的过氧化物量与生物氢化中间产物的比例相关，因此它们至少可以部分解释观察到的影响。使用毛细管电泳单链构象多态性评估加热温度和持续时间对瘤胃细菌群落的影响。瘤胃细菌种群根据加热温度显著不同，但不受加热持续时间的影响。脂肪加热影响瘤胃生物氢化，至少部分原因是加热过程中产生的氧化产物通过改变酶反应和细菌种群来影响。
