Triglyceride oil

For decades, up to about 1950, it was thought that marine fats were species-specific (Lovern, 1942 Hilditch and Williams, 1964). The advent of gas-liquid chromatography (GLC) and the pioneering analysis of menhaden (Brevoortia tyrannis) oil by Farquhar et al. (1959) slowly opened the way to the view that the fatty acid compositions of the triglyceride 

One attempt to classify fish fats (Lambertsen, 1978) is exemplified in Table 10.5. The percentages of as few as eight fatty acids of marine oils and lipids add up to about 80% of those present at 2-3% or more. Nutritionists may request 18 0, 18 2, 18 3 and 20 4, so 12 fatty acids have also been employed. Compared to lard, beef or sheep fats (see above), fish oils are considered highly unsaturated. One of the common trading standards of fish oils is the iodine value (IV). The iodine values of the monoethylenic fatty acids are 90 for 18 1 and 420 for 20 5n-3. Because of the extreme differences in IV for the typical two types of acids in Table 10.5, it was possible (Ackman, 1966) to develop an empirical formula percent polyunsaturated fatty acids = 10.7 + 0.337 (iodine value of oil—100). Table 10.6 shows the applicability of this formula. Since one of the objectives of the preparation of encapsulated fish oil products is to deliver 20 5n-3 and 22 6n-3 (Ackman et al., 1989 Sagredos, 1992), the iodine value is an easily utilized index of the suitability of raw materials for this or other uses. 

The accurate determination of individual fatty acids is not as simple as it should be. Fish oils are prone to oxidation, leading to polymer formation (Shukla and Perkins, 1991). This distorts the composition if it is related only to those monomeric fatty acids volatile as their methyl esters in GLC analyses. For this reason, Hibino et al. (1984) introduced an internal standard for GLC (tricosanoic acid, 23 0) and later Einig and 

In addition to the important saturated linear fatty acids (16 0 14 0 18 0), their iso and ante-iso counterparts and the three common iso-prenoid fatty acids are the same as those described for many terrestrial animal fats in the first part of this chapter. Usually the branched-chain proportions are iso ante-iso, the reverse of the proportions in butter. The isoprenoid group have some importance in biochemistry because optical activity is involved (Ackman and Hooper, 1973a Ackman, 1989), and this extends to geochemistry (Maxwell et al., 1972). 

The polyunsaturated fatty acids of fish oils are often said to be -3 , since the most obvious components are 18 4/i-3, 20 5/j-3 and 22 6n-3. The corresponding popular usages for the latter two fatty acids are EPA for eicosapentaenoic and DHA for docosahexaenoic. At one time, it was accepted that these were all based on plant 18 3/i-3 and were formed by chain elongation and desaturation steps taking place in the hsh. Examina- 

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RandomiZation/Interesterification. Transesterification occurs when a carboxyUc acid (acidolysis) or alcohol (alcoholysis) reacts with an ester to produce a different ester (20). Ester—ester interchange is also a form of transesterification. If completely unsaturated triglyceride oil (UUU) reacts with a totally saturated fat (SSS) in the presence of an active catalyst such as sodium, potassium, or sodium alkoxide, triglycerides of intermediate composition may be formed. 

Infrared spectra of fats and oils are similar regardless of their composition. The principal absorption seen is the carbonyl stretching peak which is virtually identical for all triglyceride oils. The most common appHcation of infrared spectroscopy is the determination of trans fatty acids occurring in a partially hydrogenated fat (58,59). Absorption at 965 - 975 cm is unique to the trans functionaHty. Near infrared spectroscopy has been utilized for simultaneous quantitation of fat, protein, and moisture in grain samples (60). The technique has also been reported to be useful for instmmental determination of iodine value (61). 

Free Fatty Acid and Saponification Value. High concentrations of free fatty acid are undesirable in cmde triglyceride oils because they... 

Triglyceride oils have declined since the 1980s and have been replaced by petroleum-derived products. However, as fossil fuels deplete the supply of petrochemicals, triglyceride-based oils are available as a renewable resource. 

Lipids. Representative fatty acid compositions of the unprocessed triglyceride oils found in the four oilseeds are given in Table 4 (see Fats and FATTY oils). Cottonseed, peanut, and sundower oils are classified as oleic—linoleic acid oils because of the high (>50%) content of these fatty acids. Although the oleic and linoleic acid content of soybean oils is high, it is distinguished from the others by a content of 4—10% of linolenic acid, and hence is called a linolenic acid oil. 

The quahty of various grades of castor oil have been prescribed by the International Castor Oil Association, Inc. (ICOAI). Specifications prescribed for the triglyceride oil derived from a plant of the genus Acinus communis are shown in Table 4. The International Castor Oil Association, Inc. has also estabUshed chemical properties to be used in the event of a dispute between buyer and seller as to the purity of the oil. These specifications are given in Table 5. 

Alkyd resin synthesis. This synthesis consists of two steps. In the first step, a triglyceride oil is reacted at ca. 250°C with polyols, such as glycerol or pentaery-thritol, in tire presence of a basic catalyst to form a monoglyceride. In the second step, phthalic anhydride, with or without another dibasic acid such as maleic anhydride, is added to the reaction medium and reacted at high temperature. The resulting product is a branched polyester (Scheme 2.56). 

Lycopene was dispersed in medium-chain triglyceride oil derived from esterification of fatty acids and glycerol composition was stable for 3 mo at 25°C, compared with dispersion on soybean oil... 

Considering the fact that the triglyceride oils used for the production of biodiesel are sulphur free, the use of biodiesel does not contribute towards the phenomenon of acid rain ... 

Special Functional Triglyceride Oils as Reactive Oligomers for Simultaneous Interpenetrating Networks... 

Castor oil and other special function group triglyceride oils can be made into low T elastomers. In SIN form with polystyrene, a... 

RGURE 6.21. Microscopic images of double emulsions stabilized by two types of silicapar-ticles of different hydrophobicity. (Top) W/OAV with triglyceride oil (scale bar = 50 am). (Bottom) OAV/O with toluene (scale bar = 20 am). (Reproduced with permission from [40] and [41].)... 

In response to this concern, many of the commercial parties involved in the development of alternative fuel and chemical feedstock resources are investigating non-food sources of triglyceride oils. 

Some plants produce triglyceride oils with naturally appended hydroxyl groups, which are capable of reacting directly with isocyanates to produce pol3nirethanes. Of these oils, the two most common are castor oil and lesquerella oil, both of which are the subject of ongoing research and development for industrial applications. 

For current information on the commercial uses of triglyceride oils, readers are directed to follow the periodic communications from the New Uses Committee of the United Soybean Board [191], which is staffed with informative professionals who remain current in the alternative applications of soybean oil, and who support the efforts of industry to develop alternative sources of feedstocks to reduce dependence on petroleum. 

Food materials leaching into the oil, breakdown of the oil itself, and oxygen absorption at the oil -air interface contribute to change the pure triglyceride oil into a mixture of hundreds of compounds. These materials increase heat transfer and also reduce the surface tension between the... 

Most commercial products are mixtures because of the way they are manufactured. For instance many surfactant hydrophobes come from assorted products such as petroleiun alkylate cuts or triglyceride oils, with a molecular weight distribution that could be narrow or wide. Usually, a purification and separation of single isomeric species would be too costly and, in most cases, pointless. Moreover, the synthesis reactions involved in the surfactant manufacturing might be the intrinsic reason of the production of a mixture, such as in the case of polycondensation of ethylene oxide which results in an often wide spread ethylene oxide munber (EON) distribution. A residual content of some intermediates or by-products might also be a significant cause for mixture effects. 

For the purposes of making polyols from these triglycerides, oils which contain a high level of unsaturation are desirable. Oils such as soy, canola, and sunflower are acceptable due to relatively low levels of saturated fatty acids, while feedstocks such as palm oil are considered unusable without further purification or refinement due to high levels of saturated fatty acids. Table 1 outlines the composition of several oils (3). 

Figure 7.28 Average droplet size d43 of O/W emulsions (20 vol% oil, 2 wt% emulsifier) containing orange oil ( ) or triglyceride oil ( ), made with gum arabic (GA), whey protein (WP) or a whey protein-maltodextrin conjugate (WP-MP) as the emulsifier, after storage for 40 days at ambient temperature (a) pH = 3.2, (b) pH = 7.0. Reproduced from Akhtar and Dickinson (2007) with permission.

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