Reaction products resulting from esterification of sucrose with saturated C16-18 (even numbered) fatty acids

Endpoint summary

Description of key information

The biological and toxicological data on sucrose esters of fatty acids (E 473) have been previously evaluated by the SCF in 1992 (SCF 1992), by JECFA in 1997 (JECFA, 1997), and recently by EFSA in 2006 (EFSA, 2004; modified on 25 January 2006), in the light of new studies on short- and long-

term toxicity in experimental animals, toxicokinetic studies in animals and humans, and human tolerance studies.

The test compound administered to rats in these studies (S-570) was a mixture consisting of 28% monoesters, 34% diesters, 21% triesters, and 10% tetra and higher esters, whereas the material given to dogs and humans (S-1170) was a mixture consisting of 57% monoesters, 28% diesters, 10%

triesters, and 1% tetra and higher esters, both with a fatty acid composition containing about 70% stearic acid and 30% palmitic acid. These materials were of a slightly different composition than the test mixtures used in the previous evaluations. Pharmacokinetic studies on sucrose esters of fattyacids in rats, dogs, and humans including studies using radioactively labelled sucrose monopalmitate (SMP), and mono- and distearate (SMS and SDS) (Mitsubishi, 1994 a, b) indicated that these esters were extensively hydrolysed in the gastrointestinal tract into well-known food constituents prior to absorption, that only small amounts of intact monoesters were absorbed, and that incompletely hydrolysed sucrose esters appeared to be excreted in the faeces. There was no evidence of tissue accumulation of the absorbed monoesters. They were completely metabolised to carbon dioxide or integrated into other endogenous constituents. (taken from EFSA Journal 2010; 8 (3): 1512)

 

Methylester:

Hydrolysis:

Esters of methanol and fatty acids have a common metabolic fate that involves hydrolysis to the carboxylic (e.g. fatty) acids and methanol.

 

Metabolism of methanol:

Methanol is polar/hydrophilic (log KOW < -0.5) and thus distributed in the aqueous compartments of the organism. However, direct urinary excretion is known to be low (<3% in humans); unchanged methanol is excreted to some extent via exhalation.

Predominating is the metabolism of methanol: initially, methanol is slowly oxidized by the enzyme alcohol dehydrogenase (ADH) to formaldehyde, which itself is oxidized very rapidly by the aldehyde dehydrogenase (ALDH) to formic acid. Finally, formic acid is slowly metabolised to CO2and H2O (metabolism using tetrahydrofolic acid in humans; see Figure 1). These are excreted via exhalation and urinary excretion as predominant excretion way; urinary excretion of formaldehyde and formic acid is possible to a low extent.

 

Metabolism of fatty acids

Linear carboxylic acids feed into physiological pathways like the citric acid cycle, sugar synthesis, and lipid synthesis. The metabolic pathway of unsaturated fatty acids differs from that of saturated fatty acids in an additional step for rearrangement of the double bond (isomerisation cis → trans) leading to the correct trans-intermediate for β-Oxidation.

References:

 

EFSA (European Food Safety Authority), 2004. Opinion of the Scientific Panel on food additives, flavourings, processing aids and material in contact with food (AFC) on sucrose esters fatty acids, E473 and glucoglycerides, E474 based on a request from the Commission related to sucrose esters of fatty acids ( E 473).

The EFSA Journal 106, 1-24. Modified on 25 January 2006.

 

JECFA (Joint FAO/WHO Expert Committee on Food Additives), 1997. Compendium of Food Additive Specifications, Addendum 5, Joint FAO/WHO Expert Committee on Food Additives, 49 th

session, Rome, 17-26 June 1997. Sucrose esters of fatty acids.

FAO Food and Nutrition Paper, 52, Add. 5, Food and Agriculture Organization of the United Nations, Rome, pp 173-181.

 

Mitsubishi (1994a). Pharmacokinetic studies of sucrose esters of fatty acids (Ses) in rats, dogs and humans. Mitsubishi Chemical Safety Institute Ltd. Report No. 3B159, Yokohama, Japan.

 

Mitsubishi (1994b). Clinical and pharmacokinetic studies of sucrose esters of fatty acids (Ses) in human. Mitsubishi Chemical Safety Institute Ltd. Report No. 4B430 (supplement to report no. 3B159), Yokohama, Japan.

 

Scientific Committee on Food (SCF), 1992. Minutes of the 83^rdMeeting of the Scientific Committee for Food held on 10 April 1992 in Brussels.Commission of the European Communites, Directorate-General for Internal market and industrial affairs. Opinion on sucroglycerides and sucrose esters, point 7.2.