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momo198548

新虫 (小有名气)

[求助] 帮忙翻译一段英文文献

Developing infant milk fat similar to human milk fat (HMF) is of great interest and a challenge to food processors. In most vegetable oils used for infant milk fat production, the sn-1,3 positions of the TAGs are occupied mainly by saturated fatty acids, while in human milk these positions contain mainly unsaturated fatty acids . The location of saturated fatty acids especially palmitic acid at the sn-2 position of triacylglycerols (TAGs) increases the efficiency of absorption of fatty acids from the lumen and also decreases calcium loss in infants . Unlike vegetable
oils, HMF contains about 40–60% palmitic acid at the sn-2 position of the TAGs。
Structured lipids (SLs) containing similar fatty acid structure as HMF can be produced by interesterification reactions using an sn-1,3-specific lipase that gives high selectivity and mimics the natural pathways of metabolic processes . Preliminary studies in our laboratory have revealed that enzymatic interesterification of tripalmitin with a vegetable oil blend containing coconut, safflower and soybean oils, using lipozyme RM IM as a biocatalyst, can be successful in the production of SL that mimic the fatty acid composition and structure of HMF. Safflower and soybean oils are two sources of polyunsaturated fatty acids that together with coconut oil, produces an acceptable combination of fat that can be employed in infant milk fat formulation . Furthermore, HMF contains small amounts of long chain polyunsaturated fatty acids (LCPUFAs), and the fortification of infant milk with these LCPUFAs by addition of fish oil is becoming increasingly popular for additional health benefits . However, the successful production of SLs for infant milk formulation can be impeded by their high susceptibility to oxidative deterioration. SLs or infant milks produced with lipids containing unsaturated fatty acids can deteriorate during storage and produce off-flavors and odors characteristic of oxidation . Furthermore, the production process for SLs increases free fatty acids (FFA) concentration, which is also responsible for off-flavor development . A high concentration of FFA in infant milk induces a rancid and bitter taste that is unacceptable. Also, unsaturated fatty acids in infant milk fat can be oxidized into hydroperoxides (primary oxidation products), which can then be rapidly decomposed to secondary oxidation products such as alkanes, alkenes, aldehydes, and ketones . Oxidative deterioration and high FFA concentration can alter the nutritional quality of SLs and render infant milks containing these lipids potentially toxic and unacceptable to consumers . Oxidation stability of structured lipids intended for infant milk formulation, provides insight on the acceptability of these milks for consumption. This paper therefore aims to characterize and study the oxidative stability of SLs intended as infant milk fat analogs.

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songe0310

木虫 (著名写手)

傻~傻得没得说的~

【答案】应助回帖

★ ★ ★ ★ ★
爱与雨下(金币+5): 2011-11-05 07:35:59
momo198548(金币+20, 翻译EPI+1): 很感激,谢谢~ 2011-11-06 19:44:40
将婴儿乳脂开发成类似于人乳脂是一件非常有趣的事情,同时这对食品加工器也是一个挑战。大多数用于生产婴儿乳脂的菜油中,三酰基甘油类成分1和3位酯键上主要是饱和脂肪酸,而人乳中则主要是不饱和脂肪酸。2位酯键上的饱和脂肪酸尤其是棕榈酸增加了儿童从官腔中吸收脂肪酸的效率,也减少了钙的流失。人乳与蔬菜油不同的是,它的三酰基甘油类成分2位酯键上含有40-60%的棕榈酸。结构脂质(SLs)可以通过采用1和3位酯键专用脂肪酶进行酯交换获得与人乳相似的脂肪酸结构,这种脂肪酶使结构脂质具有高选择性,并且其代谢过程可模拟天然的代谢途径。我们实验室的前期研究结果显示,将棕榈精与椰子油、红花油和大豆油混合,以硫辛酸酰胺RM IM为生物酶,采用酶法酯交换法能够成功得到与人乳脂肪酸成分和结构相似的结构脂质。红花油和大豆油是两种多不饱和脂肪酸类化合物的原料,它们与椰子油混合形成的脂类混合物允许添加到婴儿奶粉脂类配方中。进一步研究显示,人乳中含有少量的长链多不饱和脂肪酸(LCPUFAs),因此为了增加奶粉的健康益处,日益流行向婴儿奶粉中添加鱼油来增加长链不饱和脂肪酸。然而,由于结构脂质非常容易氧化变质,这就阻碍了生产用于婴儿奶粉配方的该类产品的成功。用脂类制成的结构脂质或婴儿乳脂中含有不饱和脂肪酸类物质,这类物质在储存期间容易变质,并产生不良气味和氧化物的气味。进一步研究显示,结构脂质生产过程中游离脂肪酸(FFA)的浓度增加也进一步增加了异味。婴儿奶粉中游离脂肪酸浓度太高会产生一种让人难以接受的酸苦味。同样,婴儿奶粉脂类中的不饱和脂肪酸可以氧化成氢过氧化物(主要氧化产物),它们很快分解成烷烃类、醛类、酮类等次级氧化产物。氧化变质和高游离脂肪酸浓度可以改变结构脂质的营养质量,使含有这些脂类的婴儿奶粉存在潜在的毒性,并不为消费者所接受。用于婴儿奶粉配方的结构脂质的氧化稳定性促使了关于这些奶粉消费的可接受性的研究。
因此,本文旨在表征和研究婴儿乳脂的类似物-结构脂质的氧化稳定性.
你就傻下去吧~~
2楼2011-11-04 20:27:29
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alvarohao

铁杆木虫 (著名写手)

【答案】应助回帖

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爱与雨下(金币+5): 2011-11-05 07:36:23
momo198548(金币+30): 很好,谢谢 2011-11-06 19:44:49
将婴儿奶粉脂肪开发成母乳脂肪(HMF)对于食品工艺师们来说,有着极大的吸引力和巨大的挑战。在大多数用于婴儿奶粉脂肪生产的植物油中,甘油三酯(TAG)中sn-1,3位主要为饱和脂肪酸,而母乳中的这些位置主要含有不饱和脂肪酸。饱和脂肪酸特别是棕榈酸在甘油三酯sn-2位上可以提高肠道吸收脂肪酸的效率并减少婴儿钙质的流失。不同于植物油,母乳在甘油三酯的sn-2位包含有40-60%的棕榈酸。结构脂(SL)含有与母乳脂肪相似的脂肪酸结构,可以通过使用具有高分离性的sn-1,3特异性脂肪酶的酯交换反应而生产出来,并且模仿了代谢过程的天然途径。本实验室的初步研究表明,通过使用脂肪酶lipozyme RM IM作为生物催化剂,三软脂酸甘油酯与含有椰子油,红花油和豆油的一种植物油混合物进行酶法酯交换反应,可以成功地生产出模仿母乳脂肪中脂肪酸成分及结构的结构脂。红花油和豆油是多不饱和脂肪酸的两个来源,并且与棕榈油一起可以生产出合格的脂肪组合以用于婴儿配方奶粉。而且,母乳脂肪中含有少量的长链多不饱和脂肪酸(LCPUFA),配有LCPUFA的婴儿配方奶粉在添加鱼油后,越来越成为增益健康的流行配方。然而,用于婴儿配方奶粉的结构脂的生产由于易受氧化变质的影响而遇到了阻碍。结构脂或包含有不饱和脂肪酸脂肪的婴儿奶粉在储藏中会变质并产生异味以及氧化后特有的气味。而且,结构脂的生产工艺增加了游离脂肪酸(FFA)浓度,也是产生异味的原因。在婴儿奶粉中高浓度的游离脂肪酸会产生令人不悦的腐臭味和苦味。并且,婴儿奶粉脂肪中的不饱和脂肪酸可以被氧化成氢过氧化物(初级氧化产物),会很快分解为二次氧化产物,如烷类,烯烃,醛类和酮类。氧化变质和高浓度游离脂肪酸会改变结构脂的营养品质,会使含有这些脂肪的婴儿奶粉产生潜在的毒性而不被消费者接受。用于婴儿配方奶粉的结构脂的氧化稳定性,可以帮助深入了解用于消费的这些奶粉的可接受度。因此本文致力于描述和研究作为婴儿奶粉脂肪同型物的结构脂的氧化稳定性。
求�?創新,勵志圖?姡�
3楼2011-11-04 21:46:31
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alvarohao

铁杆木虫 (著名写手)

and the fortification of infant milk with these LCPUFAs by addition of fish oil is becoming increasingly popular for additional health benefits
这是furthermore的后半句,我翻译错了:
原译:配有LCPUFA的婴儿配方奶粉在添加鱼油后,越来越成为增益健康的流行配方。
改为:请按楼上修改。
SLs or infant milks produced with lipids containing unsaturated fatty acids can deteriorate during storage and produce off-flavors and odors characteristic of oxidation .
原译:结构脂或包含有不饱和脂肪酸脂肪的婴儿奶粉在储藏中会变质并产生异味以及氧化后特有的气味。
改为:用含有不饱和脂肪酸的脂肪制成的结构脂或婴儿奶粉,在储藏中会变质并产生异味以及氧化后特有的气味。
以上是两个非常大错误,请楼主注意甄别。至于其它与楼上不同之处,清楼主自行选取或改写。见谅!
求�?創新,勵志圖?姡�
4楼2011-11-04 22:14:08
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