Products from triglycerides

Scheme 1 Synthesis of value added products from triglycerides and glycerol...

In order to carry out PHA production from triglycerides, the cells need to hydrolyze the triglycerides into free fatty acids that can be transported into the cells. For this, the cells need to secrete an enzyme called lipase. A wide variety of organisms is known to secrete lipolytic enzymes, mainly for lipid metabolism and signal transduction. Lipolytic enzymes can be classified into different classes, including lipases, esterases, and phospholipases (Arpigny and Jaeger 1999). Esterases are enzymes that hydrolyze ester bonds of soluble or partially soluble molecules. 

Figure 5.5 Overview of accessible products from triglycerides. (Adapted from Ref. 13.)...

Untreated silica column can be advantageously used for HPLC preseparation of PAHs from triglycerides. The capacity of a silica column to retain fat (for columns of the same particle size) depends on the column size, the mobile phase composition, as well as the type and by-products (free acids and polymerized material) of the fat injected [706,713]. Off-line HPLC-HPLC, employing silica column (250 X 4.6 mm i.d., 5 pm of particle size) for sample preparation before RP-HPLC and spec-trofluorometric detection, was successfully applied for PAH determination in edible oils [659,691] and fish [714]. After PAH elution, the silica column needs to be backflushed with dichloromethane to remove the fat. The entire sample preparation step can be automated by using a backflush valve and a programmable switching valve box [691]. 

Triglycerides. Triglycerides can be hydrolyzed to give fatty acids and glycerol (Scheme 2). The fatty acids obtained have many industrial uses, mostly for the manufacture of soap. Glycerol is currently viewed as a by-product from... 

Table I summarizes the various meats, meat constituents, and other related substances which have been analyzed, including substances reported on previously (6) as well as those for which new data are given. The substances chosen are intended to provide a cross-section of the type of inherently related material from which volatile irradiation odor and flavor compounds might be expected to form. Thus, in addition to several whole meats, the volatile irradiation products from a number of protein and lipid substances have been analyzed. Among the lipid substances included are typical whole fats and separate moieties such as triglycerides, fatty acid esters, and cholesterol, as an example of a steroid. Among the proteinaceous substances included are a protein, a polypeptide, and some individual amino acids. Finally, beef itself has been separated into a protein, a lipid, and a lipoprotein fraction, and these have been separated, irradiated, and analyzed.

Acute steatosis of the liver may have explained this presentation. In insulin overdose, the combination of greatly increased hepatic production of triglycerides from glucose and reduced production of apolipoprotein B 100 results in an insufficient increase in the transport of triglycerides in VLDL particles from liver to muscle and adipose tissue and contributes to the steatosis. 

Fatty acids are cleaved from triglycerides and metabolized through beta oxidation. This process is shown in Figure 12.41. This process clips the fatty acids into two-carbon fragments. The two-carbon fragments emerge from beta oxidation as acetyl CoA. Each acetyl CoA molecule is accompanied by the production of an NADH and a QHr Of course, when the chain is finally cut down to just two carbons, they are as an acetyl CoA. Since there are no carbon-carbon bonds to oxidatively cleave, no NADH or QH2 are produced. 

Biodiesel fuel was prepared by a two-step reaction hydrolysis and methyl esterification. Hydrolysis was carried out at a subcritical state of water to obtain fatty acids from triglycerides of rapeseed oil, while the methyl esterification of the hydrolyzed products of triglycerides was treated near the supercritical methanol condition to achieve fatty acid methyl esters. Consequently, the two-step preparation was found to convert rapeseed oil to fatty acid methyl esters in considerably shorter reaction time and milder reaction condition than the direct supercritical methanol treatment. The optimum reaction condition in this two-step preparation was 270°C and 20 min for hydrolysis and methyl esterification, respectively. Variables affecting the yields in hydrolysis and methyl esterification are discussed. 

Therefore, the purpose of the present work was to study an alternative method for biodiesel fuel production that has a lower reaction condition than the one-step supercritical methanol method, through the two-step preparation consisting of hydrolysis of triglycerides in subcritical water and subsequent methyl esterification of the fatty acids by supercritical methanol treatment. In this article, we present various parameters affecting the yield of fatty acids in hydrolysis from triglycerides followed by methyl esterification of the fatty acids. We also compare the one- and two-step preparation methods and propose a production scheme of the latter. 

Figure 2 presents the effect of the various volumetric ratios of water to rapeseed oil on the yield of fatty acids as prepared with both flow- and batch-type reaction systems at 270°C for 20 min. The volumetric ratios of 1/4 and 4 correspond to the molar ratios of 13 and 217, respectively. For the batch-type system, the hydrolysis rate of triglycerides seemed to be affected more by the amount of water, and a slightly better conversion was seen with the flow-type reaction system. Even though the volumetric ratio of 1/4 is equivalent to the molar ratio of 13 in water, which is theoretically higher than its stoichiometry of 3, the formation of fatty acids in both reaction systems was obviously low. In addition, it was found that at a volumetric ratio less than 2/3, it was difficult to separate hydrolysis products from the water portion that contained glycerol. On the other hand, the presence of water in fatty acids would have a negative effect on the methyl esterification reaction (15). 

Warabi, Y., Kusdiana, D., Saka, S., Reactivity of triglycerides and fatty adds of rapeseed oil in supercritical alcohols, Bioresource Technology, 91, 283-287, 2004 Xie, W., U, H., Alumina-supported potassium iodide as heterogeneous catalyst for biodiesel production from soybean oil, J. Molec. Catal. A Chemical, 205,1-9,... 

The production of cocamidopropyl betaine has traditionally been based on two feedstocks coconut oil and topped or stripped (C-8 and 10 removed) coconut fatty acid or methyl ester. These products are still widely used but, to achieve better colors and odors, hydrogenated feedstocks are now very frequently used, either fully hydrogenated coconut oil triglyceride or stripped, hydrogenated, distilled coconut fatty acid. These products are most frequently sold as aqueous solutions with 35% nonvolatile matter. If made from triglyceride, the betaine surfactant will contain about 2.5% glycerin by-product and 5% sodium chloride by-product in addition to the active surfactant. Products made from fatty acid or methyl ester are approximately 30% active product and slightly more than 5% sodium chloride. 

Further applications involves the analysis of both free fatty acids and fatty acids as constituents of fats, oils, etc. Tallent and Kleiman [173] analysed products from the lipolysis of oils (in addition to acids also mono-, di- and triglycerides). BSA is more suitable than an HMDS-TMCS mixture for the silylation of these compounds as more uniform products are produced. The reaction is carried out in a reaction vial in which 2—3 mg of dry lipolysis products are placed and 0.2-0.3 ml of the silylation agent (BSA—pyridine,... 

Iso, M., Chen, B., Eguchi, M., Kudo, T., and Shrestha, S. 2001. Production of biodiesel fuel from triglycerides and alcohol using immobilized lipase,/. Mol. Catal. B Enzym., 16, 53-58. 

The removal of contaminants (unreacted triglycerides, odor and color bodies, polymerized matter, and decomposition products) from split fatty acids is achieved by simple distillation.17a,b The products obtained from such straight distillations are called whole cut fatty acids (e.g., whole coconut fatty acid). 

Methylketones are present in dairy products, formed from triglycerides through g-ketoacids. 3-Methylbutanol originates from L-leucine and is present in various fermented products. The presence of such common constituents is thought to be involved in host finding for different kinds of foodstuffs by the mite. 

---