Trans fats alternatives

List, G.R. R. Reeves. reduction. Trans Fats Alternatives D.R. Kodali, G.R. List, Eds. AOCS Press Champaign, IL, 2005 pp. 72-73. 

Capillary gas chromatography is an alternative method to measure trans fats as FAMEs (AOAC 996.06 and AOCS Ce lf-96), particularly for lower concentrations (-0.5%). GC official method AOAC 996.06 (AOAC, 2001) is appropriate for the determination of fat in food products, while AOCS Ce lf-96 (AOCS, 1996) is applicable to the determination of cis and trans fatty acids in hydrogenated and re-... 

Because of worldwide interest in the health concerns of consuming trans fats, and subsequent food-labeling requirements for trans-iax content in the United Stastes and elsewhere, great interest in low-linolenate soybean oil (less than 3% linolenate) has arisen (Chapters Lipids, Food Uses for Soybean Oil and Alternatives to Trans Fatty Acids... 

The production of fat spreads as an alternative to butter led to an increased demand for solid fats. For the most part, this demand has been met by the use of partially hydrogenated vegetable oUs (Section 8.3), but concern about the health effects of trani-unsaturated acids has raised interest in an alternative way of producing fats with the required melting behavior. This can be achieved by interesterification of blends of natural or fractionated fats. Products obtained in this way will probably contain more saturated acids than their partially hydrogenated equivalents, but they will have no trans-acids. This section is devoted to interesterification carried out under the influence of a chemical catalyst (177, 186, 187). Similar reactions with enzymes are discussed in the following section. 

The use of chemical aids and technologies to stabilize lipids also represents a need to evaluate the balance between positive attributes that may reduce the risk of exposure to dietary oxidized lipids, or alternatively, negative consesquences, such as generation of tran -fatty acids derived from selective hydrogenation of vegetable oils. This chapter is intended to update the information on topics of toxicity and safety of fats and oils described earlier (6), as they relate to (1) natural consitutents of fats and oils (2) derived products of oxidation and hydrogenation (3) occurance of natural and pollutant contaminants and (4) additives used to preserve the stability, functionality, and nutritional quality of many constituents present in fats and oils. 

As the debate concerning health effects of saturated products and that of trans isomers generated during hydrogenation continues, interesterification may offer a viable alternative to the refiner. Outside the United States interesterification is used to produce hardened fats without trans isomers. These products are available in Canada and continental Europe. This technology has been available for quite some time, as a patent on the product was granted to Unilever in 1961 (22). The ability to tailor the melting point and functional crystallization characteristics without... 

The unique fatty acid composition of SBO undoubtedly contributes to its beneficial effect on some cardiovascular risk factors, particularly TC and LDL-C levels. Studies show that substituting a proportion of total calories (20%) with SBO can result in a 7—11% and 8-15% reduction in TC and LDL-C, respectively. However, only a few studies with SBO evaluated effects on BP, and most reported no benefit. Similarly, some evidence shows that SBO may reduce inflammation (specifically TNF-a and IL-6), but conclusions are limited by the small number of studies that investigated these effects. Nevertheless, the low-SFA and high-MUFA and -PUFA contents of SBO make it a healthy alternative to fats that are high in saturated and trans fatty acids. 

Solid fats can be produced by an alternative method. High-melting fats, such as palm stearin, animal fats, or fully hydrogenated oils, are mixed with oils and treated with sodium methoxide or an alkali metal. Under these conditions, ester interchange between solid and liquid TAG occurs, and the resulting fat is plastic, similar to hydrogenated oils, but does not contain trans-FA. 

However, there are serious limitations when relying only on Ag -TLC or Ag -HPLC results to analyze the TFA content of a fat-containing product. These are not independent methods but should be used to compliment GC results. The two argentation methods make it possible to analyze the mono TFA in greater detail, but they are not very suitable for the analysis of TFA with more than one double bond in the molecule. One would need to look at many other TLC bands (or HPLC peaks) to arrive at the total TFA content of a product. Analysis of all the TFA is crucial considering that we still do not know which TFA isomers are responsible for increased risk of CHD. Many of the more unsaturated FA containing trans bonds can be analyzed by GC and for that reason the results of both GC and argentation separations should be combined. Alternatively, TFA could be analyzed by FT-NIR (38), or as total TFA by FTIR (13). 

The use of methanol offers the best results in the trans-esterification of oils and fats. Compared with other alcohols, methanol requires shorter reaction times and smaller catalyst amounts and alcohol/oil molar ratios [10,12,15,16,51,52]. These advantages lead to reduced consumption of steam, heat, water, and electricity, and use of smaller processing equipment to produce the same amount of biodiesel. Biodiesel applications continue to expand. Thus, in addition to its use as fuel, biodiesel has been employed in the synthesis of resins, polymers, emulsifiers, and lubricants [53-64]. Concerning the range of applications, new biodiesel production processes should be considered as alternatives to the production based on methanol. Currently, methanol is primarily produced from fossil matter. Due to its high toxicity, methanol may cause cancer and blindness in humans, if they are overexposed to it. Methanol traces are not desired in food and other products for human consumption [15]. In contrast, ethanol emerges as an excellent alternative to methanol as it is mainly produced from biomass, is easily metabolized by humans, and generates stable fatty acid esters. Additionally, fatty acid ester production with ethanol requires shorter reaction times and smaller amounts of alcohol and catalyst compared to the other alcohols, except methanol, used in transesterification processes [11,15,16]. 

To obtain a total fatty acid profile, to include co3 fatty acids, and other potentially beneficial fatty acids such as GLA, the approach is normally straightforward and involves extraction of lipids in the presence of an appropriate, derivatization of fatty acids to methyl esters, and analysis by GC. Appropriate extraction methods, depending on the type of food and lipids presents, must be employed to extract the total lipids efficiently. An alternative is to hydrolyze the sample directly to release all the fatty acids in the free form followed by derivatisation. An appropriate methylation step is required. Alkaline methods are milder, but will only derivatize EFA. Acidic methods are used to derivatize samples containing FFA with or without EFA. Separation of FAME can normally be achieved on Carbowax type columns of medium length, but samples such as milk fats or PHVO, containing complex mixtures of trans fatty acids, require longer polar columns and may require the use of additional techniques. Milk fats also contain SCFA and specific precautions or adaptations of protocols are necessary for their analysis. 

Physical methods have also given good results in separating specific isomers. Berdeaux et al. (1998) separated the 9-cis, 11-trans and 10-trans, 12-cis isomers as fatty acid methyl esters from a CLA mixture by a series of low-temperature crystallizations from acetone with a fractional purity of >90% for each. The 10-trans, 12-cis isomer separated from the mother liquor at -58 C, followed by the 9-cis, 11-trans isomer at -6TC. The remaining mother liquor contained a mixture of 11,13 isomers. Alternatively, urea crystallization was used by Ma et al. (1999) to enrich the content of 10-trans, 12-cis isomer in CLA mixtures to 60% of the total CLA. O Shea et al. (2000) achieved enrichment of the CLA level in anhydrous milk fat by a process of dry fractionation. A soft fat fraction was produced with a 63.2% higher CLA level than the base milk. This fraction was also enriched in 11-trans 18 1 and PUFA. 

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