Fatty acids interesterification

At present, margarine producers are moving to use fractionation and interesterification to produce the required properties. A new technology uses lipase enzymes to rearrange fatty acids in a controlled way. 

An alternative method is interesterification where the fatty acids are rearranged. This can be done chemically, which gives a random distribution, or by using enzymes. The advantage of enzymes is that they are very specific in their action. It is quite possible using a lipase to remove... 

Release of fatty acids and some interesterification may also occur, but such changes are unlikely during the normal processing of milk. 

Yoon, S. H. Nakaya, H. Ito, O. Miyawaki, O. Park, K. H. Nakamura, K. Effects of Substrate Solubility in Interesterification with Riolein by Immobilized Lipase in Supercritical Carbon Dioxide. Biosci. Biotechnol. Biochem. 1998, 62, 170-172. Yu, Z. R. Rizvi, S. S. H. Zollweg, J. A. Enzymatic Esterification of Fatty Acid Mixtures from Milk Fat and Anhydrous Milk Fat with Canola Oil in Supercritical Carbon Dioxide. Biotechnol. Prog. 1992, 8, 508-513. 

Ferrari, R., Esteves, W. and Mukherjee, K. (1997) Alteration of steryl ester content and positional distribution of fatty acids in triacylglycerols by chemical and enzymatic interesterification of plant oils. J. Am. Oil Chem. Soc., 74(2), 93—96. 

Interesterification involves an exchange of acyl groups within and between triacylglycerol molecules. This re-distribution of the fatty acids results in modification of the physical properties and nutritional properties of the fat (Frede, 1991). The traditional process of interesterification involves the use of chemicals. 

Chemical interesterification randomizes the fatty acid distribution in the triacylglycerol. The extent of modification of the fat depends on the composition of the starting fat and whether a single or a blend of fats is used and the conditions of the chemical interesterification process (Mickle et al., 1963 Huyghebaert et al., 1986 Rousseau and Marangoni, 2002). 

Enzymic Interesterification of Milk Fat with Free Fatty Acids... 

Similar changes in chemical composition and melting properties were reported for chemical and enzymatic interesterification of milk fat with a non-specific lipase (Kalo et al., 1986 a, b). Both processes result in randomisation of the fatty acids. 

Solvent-free enzymatic interesterification of milk fat alone or with other fats or fatty acids provides the most acceptable route for modification of the triacylglycerol structures in milk fat and further research and development in this field is expected to provide physical and physiological benefits. From a nutritional perspective, it is of interest to examine the effects of randomized milk fat on serum cholesterol. Christophe et al. (1978) reported that substitution of native milk fat with chemically-randomized interester-ified milk fat reduced cholesterol levels in man. However, others found that there was no effect on serum cholesterol levels in man as a result of substitution of ezymatically randomized milk fat (De Greyt and Huyghebaert, 1995). Further studies are required to determine if interesterilied milk fat provides a nutritional benefit. 

Balcao, V.M., Malcata, F.X. 1998b. Interesterification and acidolysis of butterfat with oleic acid by Mucor javanicus lipase changes in the pool of fatty acid residues. Enz. Microb. Technol. 22, 511-519. 

Health concerns about trans fatty acids formed by hydrogenation have lead to the use of interesterification, fractionation, or blending of saturated and polyunsaturated oils as an alternate method to hydrogenation. It was found... 

Enzymes have been used to assist oil extraction and in degumming (phosphatides removal), splitting fatty acids from triglycerides, interesterification (rearranging fatty acids on triglyceride molecules), and preparation of specialty oils. These processes are described later in this chapter. 

Interesterification (INES) is the exchange of acyl radicals between an ester and an acid (aci-dolysis), an ester and an alcohol (alcoholysis), or an ester and an ester (transesterification), and can be random, directed, or enzymatic. The process has been called intraesterification if an exchange of positions occurs within the same molecule, and randomization if exchange occurs between molecules.44,48 The principles can be used to position fatty acids on mole-... 

The main objective in interesterification is to produce solids free from trans fatty acids for later use in compounded fat products. The final fat, or a series of base stocks, can be made for future blending. Randomization can improve the functionality of a fat, as shown... 

Enzyme interesterification is rapidly becoming popular and has the advantage of selecton of TAG positions at which fatty acids are interchanged. When 1,3 lipases are used, the... 

Fatty acid methyl esters (FAME) are the gateway to many products. Use for glycerol, a byproduct of alcoholysis interesterification. Current FAME uses include cleaning graffiti... 

The temperature optimum for interesterification is 85°C or higher, and the half-life in continuous acidolysis of spy bean oil with lauric acid at 60°C is above 2500 h. The non-specificity makes the catalyst useful in random interesterification of different fats. The catalyst has some saturated fatty acid specificity. Two lipase components (A and B) were purified. Lipase A is important for interesterification, and Lipase B is important in ester synthesis. 

Interesterification > Acidolysis (triglyceride + fatty acid) Transesterification (e.g. triglyceride + triglyceride), Reaction with the fatty acids in the 1,3-positions only Reaction with the fatty acids in all three positions... 

In the interesterification of fats, 1,3-positional specific lipases catalyze reactions in which only the fatty acids in the a-positions of the triglycerides take part, whereas positional nonspecific lipases are able to catalyze reactions in which the fatty acids from both the a- and / -positions take part. In transesterification between two types of fat, the positional non-specific lipase is therefore able to randomize the fatty acids, resulting in the same fatty acid composition in the triglycerides as obtained in the commercially important chemical randomization process. In ester synthesis, positional non-specific lipases catalyze the reaction with both primary and secondary alcohols whereas positional specific lipases are more or less specific for primary alcohols. 

To measure the activity in acidolysis, triolein was esterified with equimolar amounts of palmitic acid at 60°C by means of immobilized lipase (Fig. 4). The incorporation of palmitic acid into the triolein is measured by GIC of fatty acid methyl esters obtained after methoxylation of the triglycerides (8,9). One Batch Interesterification Unit (BIU) corresponds to 1 /xmol of palmitic acid incorporated (initial activity) into triolein per min. 

The activities in acidolysis of tricaprin with different fatty acids were measured in separate experiments, each performed like the assay for batch interesterification units. It is observed that the enzyme has seme specificity towards saturated fatty acids. This kind of specificity is unique, and has not previously been described. 

Lipase A seems to be responsible for the interesterification characteristics of the immobilized crude lipase preparation, including its unique specificity towards saturated fatty acids. Further, Lipase A can explain some of the activity found in ester synthesis with long-chain alcohols. On the other hand, Lipase B is responsible for the activity in ester synthesis of short-chain alcohols, and for some of the activity on long-chain alcohols. 

Lipase. Interesterification of triacylglycerols in the presence of a regiospecific lipase or a nonspecific lipase and free fatty acids can be used to modify the physical or nutritional characteristics of fats. Lipases from Aspergillus sp. (47,48) and Rhizopus... 

Bohenin occurs as a white to light tan, waxy solid. It is a triglyceride containing behenic acid at the 1- and 3-positions and oleic acid at the 2-position. Behenic acid is a saturated fatty acid that occurs naturally in peanuts, most seed fats, animal milk fat, and marine oils. It is produced by the interesterification of triolein and ethyl behenate in the presence of a suitable lipase enzyme preparation. It melts at approximately 52°. It is insoluble in water soluble in hexane, in chloroform, and in acetone and slightly soluble in hot ethanol. 

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