Huiles végétales et margarines : évolution de la qualité: Les solutions technologiques à la réduction des acides gras trans

Abstract

Industrial trans fatty acids (TFA) originate from partial hydrogenation and deodorisation (last step of oils & fats refining). Concerning refining, technological improvements and optimized conditions applied during the deodorisation step, lead to reduced amounts of trans isomers in vegetable oils (less than 1% or 2%), a trend encouraged since 2003 by FEDIOL. The production of margarines, spreads and shortenings with adapted properties (namely, in terms of solid fat crystals), requires the modification of “natural” oils & fats: fractionation, interesterification and hydrogenation (full or partial), among which partial hydrogenation is the only trans-producing process. Appropriate combinations of the available trans-free modification techniques together with a proper choice of the feedstock, allow to produce trans-free or low-trans fats for these applications. Thanks to these different options, the vast majority of retail margarines/fat spreads are currently below 1% TFA. Industrial margarines, according to the IMACE good manufacturing practice code, go on reducing their TFA content (target<5%). Nevertheless, some improvements should be made for certain products (puff pastry, viennoiserie…) still contributing to TFA intakes.