Enzymatic interesterification to produce zero-trans and dialkylketones-free fats from rapeseed oil

This study aims to evaluate the potential of applying enzymatic interesterification (EIE) to produce new healthy zero-trans high vitaminic content margarine fats, based on rapeseed oil (RO) only, with a specific focus on process-induced contaminants: the dialkylketones. Three blends made of RO and fully hydrogenated rapeseed oil (60:40, 70:30 and 80:20 wt:wt%) were considered. Compositional and melting properties, polymorphic behavior, appearance and textural characteristics were compared before and after interesterification. Interesterification improved both functional and textural characteristics. Enzymatic interesterification produced fats which presented similar triacylglycerol profile and physicochemical properties as the chemically interesterified one (CIE), however, preserving more tocopherols and without forming dialkylketones (process-induced contaminants). On the contrary, it was shown that after CIE, dialkylketones were formed: C18:1–C18:1 and C18:1–C18 chain-lengths being the major ones, and interestingly, their amount increased with the unsaturation in the blends. Our results indicate the great potential of enzymatic interesterification to produce new healthy fats entirely based on rapeseed oil. This study provides valuable information for the food industry, showing EIE as cutting-edge sustainable technology.