The desire to swap out trans fats and saturated fats with other healthier options is currently limited by the failure to structure healthy oils in to a solid state while maintaining their positive functions, but now researchers believe that the use of biomimicry could hold the key to structuring unsaturated fats.
“To maintain the levels of cardio-protective unsaturated fats alternative methods to structure them are desperately needed,” explained the team behind the new report, published in Lipid Technology.
Led by Tzu-Min Wang from Rutgers in the Department of Food Science, the team noted that increasing consumer and legislative pressure around the world necessitates the food industry to substitute certain hardstock fats, including partly hydrogenated fats.
“Unfortunately the only current alternative to structuring with trans fats is substituting them with saturated fats, which are often negatively viewed by the consumer,” they wrote. “As such, alternatives to traditional triacylglyceride (TAG) structuring must be vigorously pursued.”
The hunt for hardstock fats
They noted that one potential strategy for the production of better structured unsaturated fats is to utilize oleogels or molecular gels comprised of small molecules.
Unlike structuring water in foods, however, gelation of oils is much more difficult due to the poor solubility of food grade polymers, said the team – adding that currently, the only reported food biopolymer capable of gelling vegetable oils is ethyl cellulose.
“As such, research has focused mainly on the application of low molecular mass oleogelators, which assemble into three-dimensional networks, entraining the liquid oil.”
“Forces governing the assembly of the small molecules into more complex aggregates, with long-range order, are poorly understood making the rational design of these systems outside the current realm of possibility,” Tzu-Min and colleagues noted – adding that currently, determining gelation by small molecules is still an empirical science, and the vast majority of new gelators are discovered serendipitously.
From serendipity to biomimicry
“In an attempt to identify new systems capable of structuring edible oils, without relying solely on serendipitous discoveries, we turned our attention to biomimicry,” noted the team.
“Nature has a remarkable, precise ability to organize small molecules to form extremely complex supramolecular architectures and it has become an active area of materials research ranging from tissue engineering to synthetic bone matrices to ceramics,” they said – noting that it was initially their intention to find and exploit a naturally occurring self-assembling system to potentially replace some or all of the hardstock fats in processed foods.
“This approach made the intercellular lipids in the stratum corneum an interesting starting point due to the assemblies formed comprised of ceramides, free fatty acids, and cholesterol – all of which are naturally present in foods,” they said.
Indeed, they noted that aggregates of ceramides, free fatty acids and cholesterol prevent desiccation of the skin by self-assembling and impeding molecular diffusion – something which is central to creating an ideal oleogel.
The team noted that the resulting food grade oleogels, produced through the use of biomimicry principles could provide the food industry with a novel solid fat that is both readily able to replace trans fats and is also inherently healthy in its own right.
“What is truly remarkable about this system is beyond their ability to eliminate the heart unhealthy trans fats without drastically increasing the saturated fats AND while maintaining the viscoelastic properties of solid fat is that both ceramides and phytosterols have numerous beneficial health effects,” wrote the authors.
“There are numerous possible health implications for the development of a ceramide based spreadable fat product,” they added – noting that specific mixtures of ceramides, fatty acids and beta-sitosterol, dispersed in vegetable oil, “produce edible organogels that are food-grade and mimic the physical properties of margarine with NO trans fats and less than 5% added saturated fat to oils such as canola and corn oils!”
Tzu-Min and colleagues concluded that oleogels derived from stearic acid, ceramide III and beta-sitosterol to structure edible oils “has tremendous potential to create a new solid fat with a healthier profile.”
Source: Lipid Technology
Volume 27, Issue 8, pages 175–178, doi: 10.1002/lite.201500036
“Biomimicry – An approach to engineering oils into solid fats”
Authors: Tzu-Min Wang, et al