Impact of the addition of 4-vinyl-derivatives of ferulic and sinapic acids on retention of fatty acids and terpenoids in cold-pressed rapeseed and flaxseed oils during the induction period of oxidation.

Abstract

In the western diet there is an oversupply of n-6 fatty acids. This adverse trend can be balanced by the consumption of rapeseed and flaxseed oils rich in α-linolenic acid (n-3). However, the high share of this fatty acid contributes to low oxidative stability of oil. Oxidation decreases n-3 fatty acid and other bioactive compounds contents, which adversely affects oil nutritional value. In this study, the impact of ferulic and sinapic acids vinyl derivatives on the fatty acids and oil terpenoids (sterols, tocols, carotenoids, squalene) retention at the end of induction period during accelerated oxidation of rapeseed and flaxseed cold-pressed oils was investigated. It was found that the use of 4-vinylsyringol (4-VS) or 4-vinylquaiacol (4-VQ) increased the retention of intact sterols and carotenoids (at least 2-fold) and squalene (at least 4-fold). The 4-VQ addition also inhibited the α-linolenic acid loss. Unfortunately, both phenolic derivatives favoured α-tocopherol decay in rapeseed oil.