Update on Aliphatic Aldehydes in Lipid Foods

Abstract

This review provides information on the procedures and methodologies for the isolation, subsequent description and quantitative determination of aliphatic aldehydes, including the short- (C3-al to C10-al) and medium- (C12-al to C18-al) chain aldehydes and the long-chain ones (C22-al to C32-al). Aldehydes occur in numerous matrices, having both biological and commercial importance. Their physiological roles, the relevance of their presence and the incidence of their chain length are shown. Their relationship with other minor compounds such as alcohols and hydrocarbons is also reported. Special emphasis is put on the studies on the content and composition of the fractions containing the aldehydes in seed lipids and lipids from fruits and leaves. Also their presence in edible materials is commented. The different methodologies developed showed hexanal (C6-al) and nonanal (C9-al) as the most active compounds among the short-chain aldehydes, and hexacosanal (C26-al), octacosanal (C28-al) and dotriacontanal (C32-al) among the long-chain ones. In edible oils such as extra virgin olive oils, longchain aliphatic aldehydes with even carbon-atom numbers from C22 to C30 are also present and can be isolated from the waxy fraction in quantities around a hundred mg kg-1 oil, being the C26 aldehyde the most abundant one in all of the studied samples