Change in Sunflower Oil Quality and Safety Depending on Number of Deodorisation Cycles Used

Deodorisation remains a beneficial aspect of the processing of edible oils and fats and is required during the first refining and after transportation, storage, and/or further processing, such as interesterification. While there is awareness among the scientific community that repeated deodorisation may negatively impact product quality, according to some technical and processing requirements, oils, fats, and their blends can still be treated with up to 3-4 cycles of deodorisation. However, the precise changes caused by sequential deodorising processes remain unknown. This study analysed fatty acid compositions, peroxide values, anisidine values, volatile profiles, and monochloropropanediol (MCPDEs) and glycidyl (GEs) fatty acid ester contents in pressed and repeatedly deodorised sunflower oils (SFOs). The latter had higher levels of saturated fatty acids (SFAs); monounsaturated fatty acids (MUFAs); and trans fatty acids (TFAs); as well as volatile aldehydes, such as pentanal, hexanal, (E)-2-hexenal, and (E)-2-heptenal, and MCPDE contents with each successive deodorisation. Most of these compounds have the potential to cause harmful health effects. Therefore, it is necessary to limit the number of edible oil deodorisation cycles in order to maintain their quality and safety.