April 05, 2005
A largely ignored component, linolenic is one of the minor fatty acids found naturally in olive oil. Linolenic acid does not affect the flavor or keeping qualities of olive oil. The International Olive Oil Council (IOOC) has requested that the Codex Alimentarius, the world food standard setting body, change the definition of olive oil to exclude oil which has a linolenic acid level greater than .9%. Currently the level is set at 1.5%. The reasoning is that olive oil adulterated with high linolenic hazelnut or canola oil would be easier to spot.
Australians and New Zealanders think the real reason for the change is to exclude their oils from the international market. The EU may be threatened by large mechanized farms in Argentina and Australia which will soon be producing large quantities of inexpensive extra virgin oil. Climatic conditions in the Southern hemisphere tend to naturally create olive oils high in linolenic oil. If these oils cannot be legally called olive oil they would only be allowed to be labeled "fruit juice". The Australians have argued that changing the standard represents a non-tariff trade barrier.
According to the commission, The Codex Alimentarius was created in 1963 by FAO and WHO to develop food standards, guidelines and related texts such as codes of practice under the Joint FAO/WHO Food Standards Programme.
The Codex also limits the upper and lower permissible levels of the three most common fatty acids found in olive oil: oleic 50-85%, palmitic 7-20%, and linoleic 3-20%. Factors which affect the percent of the different fatty acids include latitude, climate, variety and stage of maturity of the olives.1 According to studies done by Lotti et al2, olive fruit from cool areas contain oil with more unsaturated fatty acids than fruit from dry and warm areas.
Delay in harvesting can also change fatty acid ratios; later oils have more unsaturated fatty acids, especially linoleic, instead of palmitic. Other studies have shown that year of harvest may have the most effect. European olive oil producers take advantage of this in blending commercial oils so that they do not exceed the Codex limits.
Linolenic acid contains 18 carbon atoms and three double bonds and belongs to the beneficial omega-3 family of fatty acids. An essential fatty acid which cannot be produced in the body, linolenic acid is converted to the precursors of prostaglandins and thromboxane which help decrease inflammation and blood clotting in the body.
Australia and New Zealand's lobbying efforts have led to a hold on changes to the Codex pending further input from interested parties.
1. Boskou, Olive Oil Chemistry and Technology
2. Lotti, G., R. Izzo and P. Riu. Effects of climate on acid and sterol composition of olive oil . Riv. Soc. Ital. Scien 11:115 (1985)