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不要在線翻譯,謝謝~ 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. |
鐵桿木蟲 (著名寫手)
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1 游離脂肪酸(FFA)含量 表3顯示了植物油,魚油和精油的游離脂肪酸含量。盡管椰子油的游離脂肪酸含量最低,植物油和魚油的游離脂肪酸濃度也僅為1%(表3)。結(jié)構(gòu)脂(SL)的游離脂肪酸濃度與那些原料中的濃度相當(dāng),表明短程蒸餾工藝成功地清除了大部分的由酶法酯交換反應(yīng)生成的游離脂肪酸。Akoh,Moussata 以及Nielsen等報道了相似的結(jié)果。 2 熔化性質(zhì) 表3給出了樣品的熔化性質(zhì)。植物油的熔化性質(zhì)要高于魚油,其熔點范圍在0 ℃以下。椰子油的熔化性質(zhì)與植物油類似,而紅花油和豆油的熔點分別為-17和-20℃。另一方面,相比于單獨的油份,精油的熔化性質(zhì)則不同。BFO的熔點范圍要比B1的低一些窄一些(表3),這是由于其含有魚油。然而,這些精油要比單獨的油份的熔點范圍要窄一些,這是因為這些油份中中鏈飽和脂肪酸的含量很高,熔點相近。另外,結(jié)構(gòu)脂中長鏈飽和脂肪酸(C14:0和C16:0)的含量要比單獨油份的含量高,C16:0的含量要比精油的高。結(jié)構(gòu)脂的熔化性質(zhì)要比其它油高(表3),這是因為與單獨油份和精油相比,這些油的飽和度較高,另外還因為有酯交換過程。由于飽和脂肪酸的熔點要高于不飽和脂肪酸的熔點,結(jié)構(gòu)脂通過酯交換混合進(jìn)C16:0,因此導(dǎo)致這些油的熔點較高。結(jié)構(gòu)脂的熔點與給定溫度下的物理狀態(tài)有關(guān),因此在形成像嬰兒乳這樣的產(chǎn)品時,會影響他們的性能。生育酚的添加對結(jié)構(gòu)脂的熔化性質(zhì)影響很小,應(yīng)為S1和SFO的熔點范圍與SIV和SFOV的相當(dāng)(表3)。 3 生育酚含量 表4給出了樣品中生育酚的含量。紅花油和豆油中擁有最高的生育酚值,豆油中的含量比紅花油的含量大約高67%。在這兩種油中沒有發(fā)現(xiàn)可檢測到的a-生育三烯酚。紅花油總的生育酚含量中大部分為a-生育酚,而豆油中的生育酚由c-和d-生育酚構(gòu)成。椰子油中a-生育三烯酚的含量最高。魚油中總的生育酚含量最低(表4),主要由a-生育酚構(gòu)成,還有少量的d-生育酚。Jennings和Akoh [7]報道了在未改性的鯡魚魚油中有類似的結(jié)果。精油含有大量的全部四種類型的生育酚(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。在所有樣品中,與其它生育酚同系物相比,b-生育酚的含量最低(表3)。 結(jié)構(gòu)脂在通過短程蒸餾提純后會減少生育酚的含量(表4)。在短程蒸餾過程中,精油的生育酚總量有54%的損失(表4)。Akoh和Moussata報道了類似的生育酚損失,主要原因可能是酶法工藝以及光熱作用。根據(jù)Hamam和Shahidi,在酯交換反應(yīng)中生育酚脂的形成也可能是導(dǎo)致油中內(nèi)生的生育酚損失的原因。與其他生育酚類型相比,樣品中a-生育酚的損失最多,可能是其較高的熱不穩(wěn)定性的結(jié)果,因此在蒸餾過程中更易于破壞。在結(jié)構(gòu)脂中添加混合生育酚(最高達(dá)到227ppm)作為抗氧化劑會將生育酚總量提高42-50%,與S1和SFO相比,S1V和SFOV中的生育酚總量的提高比較明顯。在濃縮樣品(SIV和SFOV)中螢石d-生育酚的含量較低的原因的是其他生育酚同分異構(gòu)體與生育酚總量按比例增長。 |

鐵桿木蟲 (著名寫手)

鐵桿木蟲 (著名寫手)

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