evaluation of certain food additives - libdoc.who.int - World Health ...
evaluation of certain food additives - libdoc.who.int - World Health ...
evaluation of certain food additives - libdoc.who.int - World Health ...
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information on methods that enable the identification <strong>of</strong> the individual rosin<br />
esters and their differentiation. This information should be submitted by the<br />
end <strong>of</strong> 2010.<br />
A toxicological monograph on GEGR was prepared. Tentative new specifications<br />
were prepared.<br />
3.1.7 Glycerol ester <strong>of</strong> tall oil rosin<br />
Explanation<br />
Glycerol ester <strong>of</strong> tall oil rosin (GETOR) was placed on the agenda <strong>of</strong> the<br />
current meeting at the request <strong>of</strong> CCFA at its fortieth session (7). The Committee<br />
had not previously evaluated GETOR. However, the Committee<br />
previously considered, at its eighteenth, twentieth, thirty-third, thirtyseventh,<br />
forty-fourth and forty-sixth meetings, a related substance, GEWR<br />
(Annex 1, references 35, 41, 83, 94, 116 and 122). At its forty-sixth meeting,<br />
the Committee allocated an ADI for GEWR <strong>of</strong> 0–25 mg/kg bw.<br />
GETOR is <strong>int</strong>ended to be used as an emulsifier/density adjustment agent for<br />
flavouring substances in non-alcoholic beverages.<br />
Chemical and technical considerations<br />
GETOR is a complex mixture <strong>of</strong> triglycerol and diglycerol esters <strong>of</strong> resin<br />
acids from tall oil rosin (TOR), with a residual fraction <strong>of</strong> monoglycerol esters.<br />
It is obtained by the esterification <strong>of</strong> TOR under a nitrogen atmosphere<br />
with <strong>food</strong>-grade glycerol and purified by steam stripping. TOR is obtained<br />
as a by-product <strong>of</strong> the kraft (paper) sulfate pulping process.<br />
TOR contains approximately 90% resin acids and 10% neutrals. The resin<br />
acid fractions are a complex mixture <strong>of</strong> isomeric diterpenoid monocarboxylic<br />
acids having the empirical formula C 20 H 30 O 2 and grouped <strong>int</strong>o three main<br />
classes: abietane, pimarane and isopimarane. Resin acids <strong>of</strong> these classes are<br />
similar in structure, differing only in the number and arrangement <strong>of</strong> double<br />
bonds or in the stereochemistry <strong>of</strong> the C-13 position. The neutral fraction is<br />
composed <strong>of</strong> esters <strong>of</strong> resin acids, esters <strong>of</strong> fatty acids and various unsaponifiable<br />
materials. The composition <strong>of</strong> the resin acid portion <strong>of</strong> the esters in the<br />
neutral fraction is similar to that <strong>of</strong> the resin acids <strong>of</strong> the acid fraction; the<br />
fatty acid portion <strong>of</strong> the esters in the neutral fraction is predominantly C 18 or<br />
higher straight-chain acids with varying degrees <strong>of</strong> unsaturation.<br />
The chemical composition <strong>of</strong> GETOR varies depending on the pine species,<br />
environmental factors, geographical differences and the techniques used in<br />
the processes <strong>of</strong> rosin purification and refinement. During the esterification<br />
procedure, because <strong>of</strong> the high temperature and severe conditions employed,<br />
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