Linoleic acid physical properties

In the area of moleculady designed hot-melt adhesives, the most widely used resins are the polyamides (qv), formed upon reaction of a diamine and a dimer acid. Dimer acids (qv) are obtained from the Diels-Alder reaction of unsaturated fatty acids. Linoleic acid is an example. Judicious selection of diamine and diacid leads to a wide range of adhesive properties. Typical shear characteristics are in the range of thousands of kilopascals and are dependent upon temperature. Although hot-melt adhesives normally become quite brittle below the glass-transition temperature, these materials can often attain physical properties that approach those of a stmctural adhesive. These properties severely degrade as the material becomes Hquid above the melt temperature. 

Jones E L, Shingfield K J, Kohen C, Jones A K, Lupoli B, Grandison A S, Beever D E, Williams C M, Calder P C and Yaqoob P (2005), Chemical, physical, and sensory properties of dairy products enriched with conjugated linoleic acid , Journal of Dairy Science, 88, 2923-2937. 

A large number of heterogeneous catalysts have been tested under screening conditions (reaction parameters 60 °C, linoleic acid ethyl ester at an LHSV of 30 L/h, and a fixed carbon dioxide and hydrogen flow) to identify a suitable fixed-bed catalyst. We investigated a number of catalyst parameters such as palladium and platinum as precious metal (both in the form of supported metal and as immobilized metal complex catalysts), precious-metal content, precious-metal distribution (egg shell vs. uniform distribution), catalyst particle size, and different supports (activated carbon, alumina, Deloxan , silica, and titania). We found that Deloxan-supported precious-metal catalysts are at least two times more active than traditional supported precious-metal fixed-bed catalysts at a comparable particle size and precious-metal content. Experimental results are shown in Table 14.1 for supported palladium catalysts. The Deloxan-supported catalysts also led to superior linoleate selectivity and a lower cis/trans isomerization rate was found. The explanation for the superior behavior of Deloxan-supported precious-metal catalysts can be found in their unique chemical and physical properties—for example, high pore volume and specific surface area in combination with a meso- and macro-pore-size distribution, which is especially attractive for catalytic reactions (Wieland and Panster, 1995). The majority of our work has therefore focused on Deloxan-supported precious-metal catalysts. 

Conjugated linoleic acid (CLA) may have a role in improving the nutritional and health properties of milk fat (Wahle et al., 2004 see Chapter 3). A range of lipases was compared for their efficacy of catalysing the incorporation of CLA into milk fat in solvent-free systems (Garcia et al., 2000). It was concluded that it was technically feasible to incorporate CLA into milk fat with the use of immobilised Candida antarctica lipase. However, the nutritional benefits and physical properties of the CLA-enriched milk fat need to be investigated prior to consideration of this technology for industrial application. 

Both acid oil and the free fatty acids obtained in the physical refining may be incorporated in the manufacture of soap. In view of its high linoleic acid content (in particular when originating in the refining of regular sunflower oil), soapstock does not make a fatty material of good properties for the manufacture of toilet soap. To this end, it is blended in relatively low proportions with other more appropriate fatty materials. It is used in cattle producer countries also producing sunflower oil as a means to reduce the titer of beef tallow or of the beef tallow/coconut oil blend. 

Fats can be solid or liquid. This physical property is a direct effect of the fatty acid substituents that are present in them. When fats are in their liquid state they are commonly called oils. Broadly we can generalize that solid fats mainly contain saturated fatty acids, and liquid fats mainly contain unsaturated fatty acids. We should not confuse this generalization with the fact that the naturally occurring fats and oils contain many different types of fatty acids, both saturated and unsaturated. The physical properties of fats are mostly a function of the fatty acids that are present in them. For example, human stored fat contains predominantly oleic acid (a saturated fatty acid) which constitutes about 47 % of the total fatty acid content. It also contains palmitic acid, linoleic acid, stearic acid, myristic acid, and other fatty acids in decreasing amounts respectively. 

Cocoa butter (CB) is a highly valued ingredient primarily used in the confectionery industry due to its specific physical and chemical properties. CB is solid at room temperature (below 25 °C), and liquid at body temperature (—37 °C) [43], Furthermore, the predominant presence of symmetrical TAG, about 90 % of the TAG species in CB, is mainly responsible for the functionality of this fat [44], The major FAs of cocoa butter are palmitic acid (Cl6) 25-33.7 %, stearic acid (C18 0) 33.7-40.2 %, oleic acid (C18 l) 26.3-35 % and linoleic acid... 

The physical states of lipid systems affect the distribution of antioxidants and influence their activity. a-Tocopherol and Trolox exhibit complex interfacial properties between air-oil and oil-water interfaces that significantly affect their relative activities in different lipid systems (see Chapter 10). In the bulk oil system, the hydrophilic Trolox is apparently more protective by being oriented in the air-oil interface (Figure 10.8). In the emulsion system, the lipophilic a-tocopherol is more protective by being oriented in the oil-water interface. Because of its tendency to form micelles, linoleic acid is not an appropriate lipid for testing antioxidants since their behavior in this substrate would be significantly different from that in foods composed mainly of triacylglycerols. 

Carotene-linoleic acid Bleaching of j3-carotene in Unoleic acid emulsified with Tween-20, monitored hy carotene destruction (460 nm) Not specific, influenced by physical micelle properties of emulsion, high ratio of Tween-20/linoleic acid, inappropriate substrate Kanner et al. (1977)... 

Identifying inexpensive, renewable substrates and cosubstrates for PHA production, as well as novel feedstocks/monomers (e.g. tall oils produced as oleic and linoleic acid-rich byproducts from the wood pulping processes) to enhance the economics and physical properties of PHAs will help to advance PHA polymers to greater and more widespread appUcations. UtiUzation of renewable resources, such as those derived from forest biomass could contribute to substantial reductions in PHA production cost and creation of novel polymers and production processes. 

The utility of oil is defined by the composition of the fatty acids acylated on the glycerol backbone (Specter 1999, Voelker and Kinney 2001). The composition of fatty acids differing in structure directly affects the physical and chemical properties of oil, which in turn will influence applications and industrial value. Edible oils for human consumption are predominantly comprised of six common fatty acids palmi-tate (16 0), palmitoleate (16 1-9), stearate (18 0), oleate (18 1-9), linoleate (18 2-9,12),... 

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