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不要在线翻译，谢谢~ 1Free Fatty Acid Content The FFA content of the vegetable oils, fish oil and oil blends are given in Table 3. Although coconut oil had the lowest FFA content, the vegetable oils and oil blends all had FFA concentrations \1%, (Table 3). The FFA concentrations in the SLs were comparable to those of the starting materials, indicating that the short-path distillation process was successful in removing most of the FFAs generated during the enzymatic interesterification reaction. Akoh and Moussata and Nielsen et al. reported similar results of FFA removal using short-path distillation. 2Melting Profile The melting profiles of the samples are given in Table 3.The vegetable oils have higher melting profiles than fish oil, which has a melting point range below 0 C. Coconut oil has a melting profile similar to that of the vegetable oils, while safflower and soybean oils have melting points of -17 and -20C, respectively. The oil blends on the other hand showed different melting profiles relative to their individual oil content. BFO had a slightly lower and narrower melting point range than B1 (Table 3), which is due to its fish oil content. However, these oil blends appeared to have a narrower melting profile than the individual oils, which are attributable to higher content of medium-chain saturated fatty acids, with closer melting points. The SLs on the other hand had higher contents of long-chain saturated fatty acids (C14:0 and C16:0) in comparison to the individual oils, and higher contents of C16:0 in comparison to the oil blends. The SLs had higher melting profiles than the other oils (Table 3), attributable to the high degree of saturation of these oils relative to the individual oils and oil blends, and to the interesterification process. Since saturated fatty acids have higher melting points than unsaturated fatty acids, the incorporation of C16:0 in the SLs by interesterification therefore led to higher melting profiles in these oils. The melting point of the SLs is relevant to their physical state at a given temperature, which therefore affects their performance when used in the formulation of products like infant milks. Tocopherol addition had minimal effect on the melting profiles of the SLs, because the melting point range of S1 and SFO were comparable to those of SIV and SFOV (Table 3). 3.Tocopherol Content The tocopherols contents of the samples are given in Table 4.Safflower and soybean oil had the highest total tocopherol values, with soybean oil having about 67% higher tocopherols than safflower oil. No detectable a-tocotrienol was found in both oils. Total tocopherol content of safflower oil consists mostly of a-tocopherol, while that of soybean oil consists of c- and d-tocopherols. Coconut oil had the highest content of a-tocotrienol. Fish oil had the lowest total tocopherol content (Table 4) consisting mainly of a-tocopherol and small amounts of d-tocopherol. Jennings and Akoh [7] reported similar tocopherol results for unmodified menhaden fish oil. The oil blends contained significant amounts of all four types of tocopherols (a, b, c, d) and a-tocotrienol, with a- and ctocopherol making the highest contribution to the total. b- Tocopherol was low in all samples relative to the other tocopherol homologues (Table 3). Purification of the SLs by short-path distillation had a negative impact on the tocopherol content (Table 4). There was a 54% loss in total tocopherol content from the oil blends during the short-path distillation processes (Table 4). Akoh and Moussata reported similar tocopherol losses, where enzyme processing and exposure to light and heat may be responsible for the losses. According to Hamam and Shahidi ，the formation of tocopheryl esters during the interesterification reaction might also be responsible for the loss of endogenous tocopherols present in the oils. There were higher losses of atocopherol in the samples relative to the other tocopherol types, which might be as a result of its higher heat lability and therefore greater susceptibility to destruction during the short-path distillation process. The addition of mixed tocopherols (up to 227 ppm) as antioxidants to the SLs increased their total tocopherol content by about 42–50%, which is apparent in the total tocopherol content of S1V and SFOV, with respect to S1 and SFO. The lower content of cand d-tocopherol in the enriched samples (SIV and SFOV) is due to the proportionate increase in other tocopherol isomers, with respect to total tocopherol content. |
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alvarohao
铁杆木虫 (著名写手)
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4楼2011-11-17 09:39:41
alvarohao
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【答案】应助回帖
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sltmac(金币+5): 辛苦，额外奖5BB 2011-11-17 08:57:59
momo198548(金币+60, 翻译EPI+1): 太感谢了，我还有一篇求助没人回复，跟这个是一篇文献里的，如果有时间的话帮忙翻译一下吧，嘿嘿 2011-11-17 14:38:22
sltmac(金币+5): 辛苦，额外奖5BB 2011-11-17 08:57:59
momo198548(金币+60, 翻译EPI+1): 太感谢了，我还有一篇求助没人回复，跟这个是一篇文献里的，如果有时间的话帮忙翻译一下吧，嘿嘿 2011-11-17 14:38:22
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1 游离脂肪酸（FFA）含量 表3显示了植物油，鱼油和精油的游离脂肪酸含量。尽管椰子油的游离脂肪酸含量最低，植物油和鱼油的游离脂肪酸浓度也仅为1%（表3）。结构脂（SL）的游离脂肪酸浓度与那些原料中的浓度相当，表明短程蒸馏工艺成功地清除了大部分的由酶法酯交换反应生成的游离脂肪酸。Akoh，Moussata 以及Nielsen等报道了相似的结果。 2 熔化性质 表3给出了样品的熔化性质。植物油的熔化性质要高于鱼油，其熔点范围在0 ℃以下。椰子油的熔化性质与植物油类似，而红花油和豆油的熔点分别为-17和-20℃。另一方面，相比于单独的油份，精油的熔化性质则不同。BFO的熔点范围要比B1的低一些窄一些（表3），这是由于其含有鱼油。然而，这些精油要比单独的油份的熔点范围要窄一些，这是因为这些油份中中链饱和脂肪酸的含量很高，熔点相近。另外，结构脂中长链饱和脂肪酸(C14:0和C16:0)的含量要比单独油份的含量高，C16:0的含量要比精油的高。结构脂的熔化性质要比其它油高（表3），这是因为与单独油份和精油相比，这些油的饱和度较高，另外还因为有酯交换过程。由于饱和脂肪酸的熔点要高于不饱和脂肪酸的熔点，结构脂通过酯交换混合进C16:0，因此导致这些油的熔点较高。结构脂的熔点与给定温度下的物理状态有关，因此在形成像婴儿乳这样的产品时，会影响他们的性能。生育酚的添加对结构脂的熔化性质影响很小，应为S1和SFO的熔点范围与SIV和SFOV的相当（表3）。 3 生育酚含量 表4给出了样品中生育酚的含量。红花油和豆油中拥有最高的生育酚值，豆油中的含量比红花油的含量大约高67%。在这两种油中没有发现可检测到的a-生育三烯酚。红花油总的生育酚含量中大部分为a-生育酚，而豆油中的生育酚由c-和d-生育酚构成。椰子油中a-生育三烯酚的含量最高。鱼油中总的生育酚含量最低（表4），主要由a-生育酚构成，还有少量的d-生育酚。Jennings和Akoh [7]报道了在未改性的鲱鱼鱼油中有类似的结果。精油含有大量的全部四种类型的生育酚（a，b，c，d）以及a-生育三烯酚，其中a-和c-生育酚的含量最高。在所有样品中，与其它生育酚同系物相比，b-生育酚的含量最低（表3）。 结构脂在通过短程蒸馏提纯后会减少生育酚的含量（表4）。在短程蒸馏过程中，精油的生育酚总量有54%的损失（表4）。Akoh和Moussata报道了类似的生育酚损失，主要原因可能是酶法工艺以及光热作用。根据Hamam和Shahidi，在酯交换反应中生育酚脂的形成也可能是导致油中内生的生育酚损失的原因。与其他生育酚类型相比，样品中a-生育酚的损失最多，可能是其较高的热不稳定性的结果，因此在蒸馏过程中更易于破坏。在结构脂中添加混合生育酚（最高达到227ppm）作为抗氧化剂会将生育酚总量提高42-50%，与S1和SFO相比，S1V和SFOV中的生育酚总量的提高比较明显。在浓缩样品（SIV和SFOV）中萤石d-生育酚的含量较低的原因的是其他生育酚同分异构体与生育酚总量按比例增长。 |
2楼2011-11-16 21:30:08
alvarohao
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3楼2011-11-16 21:31:07