Interesterified trans-free fats rich in sn-2 nervonic acid prepared using Acer truncatum oil, palm stearin and palm kernel oil, and their physicochemical properties

- Trans-free margarines containing nervonic acid were prepared via interesterification.
- More nervonic acids were located at sn-2 position of the interesterified fats.
- All interesterified fats showed satisfied contents of tocopherol.
- The interesterified fats showed SFC values less than 2% at 40 °C.
- The interesterified fats exhibited only spherulitic needle-like crystals in β′ form.

This study obtained trans-free fats containing nervonic acid, a fatty acid with beneficial effects for mental health. Four fats containing 1.28-2.41% (w/w) nervonic acid were prepared by chemical or enzymatic interesterification of palm stearin (PS), Acer truncatum oil (ATO) and palm kernel oil (PKO). The chemical procedure was catalyzed using MeONa, whereas the enzymatic procedure was catalyzed with a 1,3-specific lipase. As a result, the interesterified fats showed a similar fatty acid profile to their corresponding physical blends measured by gas chromatography, but contained more nervonic acids at the sn-2 position, which was more conducive to metabolism and absorption. The content of tripalmitoylglycerol (PPP) and 1,3-dipalmitoyl-2-oleoyl glycerol (POP) or 1,2-dipalmitoyl-3-oleoyl glycerol (PPO) in the interesterified fats decreased significantly, resulting in improved plasticities. All interesterified fats showed a satisfactory content of tocopherols and oxidative stability. A combination of differential scanning calorimetry, X-ray diffraction spectroscopy and polarized light microscopy results suggested that the interesterified fats formed spherulitic needle-like crystals in the β′ form, while the physical blends formed dendritic crystals in the β form. These data indicated that the trans-free interesterified fats rich in nervonic acid may have a great potential in margarine applications.