Emulsion oil concentration affects flavour release - study
the emulsion, says new research from Canada that offer insights
into better formulation and flavour.
"The important role of emulsion oil content on flavour release profile has been shown," wrote lead author Helene Giroux in the Journal of Food Science. "It appears that the hydrophobic flavour release profile in oil-in-water emulsion could be optimised by appropriate alteration of emulsion composition." How consumers sense food is crucial knowledge for a food industry constantly organising the building blocks of new food formulations. Not only did the researchers provide significant evidence for the relationship between emulsion oil content and flavour release, they also report a new technique for measuring flavour release that offers a "rapid, simple and sensitive instrumental approach in real time." The technique, a modification of gas chromatography, enabled the researchers to evaluate the effect of protein, oil and aroma concentrations on flavour release from model emulsions. "Flavour release from food depends on the composition and the microstructure of the matrix, the properties of aroma compounds (molecular weight, solubility, hydrophobicity, and so on), and their interactions with other food components. Proteins, lipids, and polysaccharides have been shown to affect the rate of flavour release because of their ability to bind, solubilise, or retard the mass transfer of flavours," said the researchers from Agri-Food Canada. Giroux and colleagues used the ester ethyl hexanoate as the hydrophobic (fat-soluble) aroma compound, and report that flavour release gradually decreased over time. "It appears that slow transfer of hydrophobic aroma compounds from the oil phase to the aqueous phase is responsible for the decreasing intensity observed," they wrote. They also report that the intensity of the ethyl hexanoate aroma decreased as the oil concentration of the emulsion increased, indicated that the oil phase acts as a reservoir for the ester. "For most aroma compounds, the effect of oil on their release is greater than that of any other ingredient," said Giroux. While confirming previous studies about the release of flavour, the study also showed that the "proposed method to monitor aroma release profile from oil-in-water emulsions showed satisfactory performance." Despite such potential, the method is currently limited by being able to only measure one compound at a time, they said. Taste is a key driver in the €3.2 trillion global food industry and a greater understanding of the physiology of consumers, could lead to strong market advantages. Source: Journal of Food Science (Blackwell Publishing) March 2007, Volume 72, Issue 2, Pages S "Characterization of Hydrophobic Flavor Release Profile in Oil-in-Water Emulsion" Authors: H.J. Giroux, V. Perreault, M. Britten