Acrolein as a Major Volatile in the Early Stages of Fish Oil TAG Oxidation.

Fish oil rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) is known to have an unpleasant smell, even at low oxidation levels. Therefore, it is highly important to know the major volatiles formed during the early stages of fish oil oxidation. Comparative study with solid-phase microextraction (SPME) and static headspace (SHS) methods showed that 2-propenal (acrolein) was formed as the major volatile from the beginning of fish oil triacylglycerol (TAG) oxidation. The effectiveness of SPME extraction on each volatile was different from each fiber. Among the three different SPME fibers used in the present study, carboxen/polydimethylsiloxane (CAR/PDMS) was determined to be a better fiber for measuring the volatiles, including acrolein. The present study also showed that the non-selective SHS method is useful for determining the characteristic volatile formation in the early stages of fish oil TAG oxidation.

Inhibitory Effect of Dihydrosphingosine with α-Tocopherol on Volatile Formation during the Autoxidation of Polyunsaturated Triacylglycerols.

The effect of dihydrosphingosine (d18:0) on triacylglycerol (TAG) oxidation was examined with and without α-tocopherol. Three types of TAG from fish, linseed, and soybean oil were oxidized at 50°C to determine the effect of dihydrosphingosine (d18:0) with or without α-tocopherol on triacylglycerol (TAG) oxidation. The analysis of oxygen consumption and total volatile formation demonstrated a small effect of d18:0 on TAG oxidation in the absence of α-tocopherol. On the other hand, the combination of d18:0 with α-tocopherol showed strong antioxidant activity and completely inhibited volatile formation within 1400 h for soybean oil TAG, 650 h for linseed oil TAG, and 380 h for fish oil TAG.