Animal Nutrition Group, Wageningen University, Wageningen, the Netherlands.
J Dairy Sci. 2010 Nov;93(11):5286-99. doi: 10.3168/jds.2010-3144.
Rumen biohydrogenation kinetics of C18:3n-3 from several chemically or technologically treated linseed products and docosahexaenoic acid (DHA; C22:6n-3) addition to linseed oil were evaluated in vitro. Linseed products evaluated were linseed oil, crushed linseed, formaldehyde treated crushed linseed, sodium hydroxide/formaldehyde treated crushed linseed, extruded whole linseed (2 processing variants), extruded crushed linseed (2 processing variants), micronized crushed linseed, commercially available extruded linseed, lipid encapsulated linseed oil, and DHA addition to linseed oil. Each product was incubated with rumen liquid using equal amounts of supplemented C18:3n-3 and fermentable substrate (freeze-dried total mixed ration) for 0, 0.5, 1, 2, 4, 6, 12, and 24h using a batch culture technique. Disappearance of C18:3n-3 was measured to estimate the fractional biohydrogenation rate and lag time according to an exponential model and to calculate effective biohydrogenation of C18:3n-3, assuming a fractional passage rate of 0.060/h. Treatments showed no differences in rumen fermentation parameters, including gas production rate and volatile fatty acid concentration. Technological pretreatment (crushing) followed by chemical treatment applied as formaldehyde of linseed resulted in effective protection of C18:3n-3 against biohydrogenation. Additional chemical pretreatment (sodium hydroxide) before applying formaldehyde treatment did not further improve the effectiveness of protection. Extrusion of whole linseed compared with extrusion of crushed linseed was effective in reducing C18:3n-3 biohydrogenation, whereas the processing variants were not different in C18:3n-3 biohydrogenation. Crushed linseed, micronized crushed linseed, lipid encapsulated linseed oil, and DHA addition to linseed oil did not reduce C18:3n-3 biohydrogenation. Compared with the other treatments, docosahexaenoic acid addition to linseed oil resulted in a comparable trans11,cis15-C18:2 biohydrogenation but a lesser trans10+11-C18:1 biohydrogenation. This suggests that addition of DHA in combination with linseed oil was effective only in inhibiting the last step of biohydrogenation from trans10+11-C18:1 to C18:0.
评估了几种化学或技术处理的亚麻籽产品中 C18:3n-3 的瘤胃生物氢化动力学，以及向亚麻籽油中添加二十二碳六烯酸（DHA；C22:6n-3）的效果。评估的亚麻籽产品包括亚麻籽油、压碎的亚麻籽、甲醛处理的压碎的亚麻籽、氢氧化钠/甲醛处理的压碎的亚麻籽、全压碎亚麻籽（2 种加工变体）、压碎的亚麻籽（2 种加工变体）、微粉化压碎的亚麻籽、市售的压碎亚麻籽、包封的亚麻籽油和向亚麻籽油中添加 DHA。使用分批培养技术，将每种产品与瘤胃液一起孵育，添加等量的补充 C18:3n-3 和可发酵底物（冷冻干燥的全混合日粮），分别在 0、0.5、1、2、4、6、12 和 24 小时时测量 C18:3n-3 的消失情况，以根据指数模型估计部分生物氢化率和滞后时间，并计算 C18:3n-3 的有效生物氢化，假设部分通过速率为 0.060/h。处理对瘤胃发酵参数没有影响，包括气体产生率和挥发性脂肪酸浓度。亚麻籽的技术预处理（压碎）后进行甲醛化学处理导致 C18:3n-3 有效免受生物氢化。在应用甲醛处理之前进行额外的化学预处理（氢氧化钠）并不能进一步提高保护效果。与压碎的亚麻籽相比，全压碎的亚麻籽的挤出处理有效地降低了 C18:3n-3 的生物氢化，而加工变体在 C18:3n-3 的生物氢化方面没有差异。压碎的亚麻籽、微粉化压碎的亚麻籽、包封的亚麻籽油和向亚麻籽油中添加 DHA 并没有降低 C18:3n-3 的生物氢化。与其他处理相比，向亚麻籽油中添加 DHA 导致类似的 trans11,cis15-C18:2 生物氢化，但 trans10+11-C18:1 生物氢化减少。这表明，DHA 与亚麻籽油的添加仅在抑制从 trans10+11-C18:1 到 C18:0 的生物氢化的最后一步有效。
