Hydrogenation trans fatty acids from

Toxicity, chemicals and, 25-26 Trans fatty acid, from hydrogenation of fats, 232-233 from vegetable oils, 1063 Transamination, 1165-1168 mechanism of, 1167... 

The hydrogenation process also forms unnatural trans fatty acids from natural cis fatty acids (see The World of Chemistry, C/s and Trans Fatty Acids and Your Health"). 

A few fatty acids with trans double bonds (trans fatty acids) occur naturally but the major source of trans fats comes from partial hydrogenation of vegetable oils m for example the preparation of margarine However the same catalysts that catalyze the... 

Some of the fatty acids found in the diets of developed nations (often 1 to 10 g of daily fatty acid intake) are trans fatty acids— fatty acids with one or more double bonds in the trans configuration. Some of these derive from dairy fat and ruminant meats, but the bulk are provided by partially hydrogenated vegetable or fish... 

Small amounts of trans-unsamrated fatty acids are found in ruminant fat (eg, butter fat has 2-7%), where they arise from the action of microorganisms in the rumen, but the main source in the human diet is from partially hydrogenated vegetable oils (eg, margarine). Trans fatty acids compete with essential fatty acids and may exacerbate essential fatty acid deficiency. Moreover, they are strucmrally similar to samrated fatty acids (Chapter 14) and have comparable effects in the promotion of hypercholesterolemia and atherosclerosis (Chapter 26). 

Some of the unsaturated fats ingested by ruminants are partially hydrogenated by bacteria in the rumen. In consequence, milk fat, dairy products, as well as beef and mutton fat, also contain small amounts of trans isomers, about 2 to 9%. However, in fat from ruminants the main trans fatty acid is vaccenic (18 1 t 11), while in hydrogenated fats it is elaidic (18 1 t 9) (Figure 13.14). 

At partial hydrogenation of triglycerides, the traditional process gives high amounts of transfatty acids. Oils with trans-fatty acid concentrations acceptable from medical point of view can be produced using our new process [11],... 

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. 

Trans-Fatty Acid Content. Trans-fatty acids arise during refining of vegetable oils as well as during hydrogenation, or from attempts to eliminate the sterol fraction of seed oils with a fatty acid composition similar to that of olive oil. Methyl esters are analyzed by capillary column GLC (76, 77). The following hmits (% m/m) are mandatory (12) ... 

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