An alternative to trans fats?

The potential ban on trans fats could mean a significant burden on food processors, as they will need to reformulate any products containing trans fats. But new research from The City College of New York could offer processors an alternative to structured oil products containing saturated and trans fatty acids.

Using low-calorie sugars as a structuring agent, the research team - led by Professor of Chemistry George John - reported the successful transformation of vegetable oils to a semi-solid form.

The team tested two sugar alcohol-based gelators, mannitol dioctanoate (M8) and sorbitol dioctanoate (S8), as structuring agents for four refined vegetable oils: canola, olive, soybean and grape seed oil. Both M8 and S8 are amphiphile - molecules that are attracted to water and fats - consisting of two octanoic acid chains (C8) appended to a sugar alcohol molecule.

“We have demonstrated the first sugar-based thickening agents for oil,” said Professor John. He added that the two agents meet both Food & Drug Administration and GRAS (Generally Recognized as Safe) safety specifications, so they can be used for food processing.

Both M8 and S8 demonstrated excellent gelation tendencies for all of the oils that were tested, and the gels remained stable for several months. When mixed with the oils, the gelation agents self-assembled into three-dimensional crystalline networks that encapsulated the oils in liquid stage. Optimal gelation was achieved at structuring agent concentrations between 3 and 5%.

However, some differences between the two agents were reported. For example, mannitol gels were opaque in appearance while those made with sorbitol were translucent. That was because M8 yields a more densely packed network while the network of S8 gels consisted of needle-like microcrystallites.

Mannitol was found to be a more efficient gelator, producing stronger gels. However, Professor John pointed out that sorbitol-based gels, which have finer structures and appear more translucent, would be better suited for specific applications.

“The multifunctionality and tunability of sugar-based gelators presents opportunities to develop next-generation oil thickeners,” Professor John said.

The findings were reported in the 15 November issue of the Journal of Agricultural Food Chemistry.