New research suggests that monoglyceride (MG) ‘crystals’ formed in emulsions have the potential to structure oil in water emulsions for more control of flavor release – with possible applications in reduced fat emulsions.
The study – published in Food Research International – investigated the effect of monoglyceride on the properties and subsequent flavor of emulsions, when compared to standard emulsifiers (tween 20 and whey protein isolate).
Led by Dr Song Miao of Teagasc Food Research Centre, Ireland, the research team report that when dispersed in oil above melting point monoglyceride forms “self-assembled structures (liquid crystal) on cooling, which have the potential to structure oil in emulsion systems.”
They revealed that such monoglyceride structures could be used to help control flavor release in emulsion systems, and may have potential “to modify flavor release in fat-reduced food”.
Flavor plays an important role in food preference. As such many studies have investigated the mechanisms of flavor release from foods in order to develop foods with desired sensory properties.
However flavor release in emulsion systems is more complex than other systems, and is often highly related to the properties of the flavor molecules and those molecules' interactions with other food components – such as oils and emulsifying or thickening agents.
“It is now commonly accepted that the emulsifiers play an important role in modifying the behavior of flavor release, not only because emulsifiers largely determine the properties of emulsions, but also because the emulsifier molecules are likely to bind flavor molecules,” wrote Miao and his team.
They explained that the study aimed to understand the effects of oil content, monoglyceride content, and emulsifier type on the development of self-assembled MG structures – and the resulting properties of these modified emulsions.
Structured oil in water emulsions containing monoglyceride (Dimodan, Danisco) were prepared with two standard emulsifiers, tween 20 (Sigma-Aldrich) and whey protein isolate (BiPro, Davisco Food International). All emulsions were reported to show good stability during storage, with the authors noting that gel properties were affected by the content of oil and MG.
“When limonene was introduced into the oil phase of these emulsions, a delay in the release of limonene in MG structured emulsions was observed,” they said, noting that changes in the emulsifier types and oil contents were found to greatly influence limonene release.
Miao revealed that flavor release was lower from MG structured emulsions compared – noting that reductions in oil content increased flavor release.
“The results of this study demonstrated the potential of using MG structured emulsion for controlled release of flavors, possibly in fat-reduced systems."
Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2012.04.002
“Effect of monoglyceride self-assembled structure on emulsion properties and subsequent flavor release”
Authors: L. Mao, B. O'Kennedy, Y.H. Roos, J. Hannon, S. Miao