Modeling flavor release

J Castellano, NH Snow. Modeling flavor release using inverse gas chromatography/mass spectrometry. J Agric Food Chem 49 4296-4299, 2001. 

Bylaite, E., Adler-Nissen, J., and Meyer, A.S. Effect of xanthan on flavor release from thickened viscous food model systems, J. Agric. Food Chem., 53(9) 3577-3583, 2005. 

Equilibrium concentrations describe the maximum possible concentration of each compound volatilized in the nosespace. Despite the fact that the process of eating takes place under dynamic conditions, many studies of volatilization of flavor compounds are conducted under closed equilibrium conditions. Theoretical equilibrium volatility is described by Raoulf s law and Henry s law for a description of these laws, refer to a basic thermodynamics text such as McMurry and Fay (1998). Raoult s law does not describe the volatility of flavors in eating systems because it is based upon the volatility of a compound in a pure state. In real systems, a flavor compound is present at a low concentration and does not interact with itself. Henry s law is followed for real solutions of nonelectrolytes at low concentrations, and is more applicable than Raoult s law because aroma compounds are almost always present at very dilute levels (i.e., ppm). Unfortunately, Henry s law does not account for interactions with the solvent, which is common with flavors in real systems. The absence of a predictive model for real flavor release necessitates the use of empirical measurements. 

Roberts, D.D. and Acree, T.E. 1996b. Retronasal flavor release in oil and water model systems with an evaluation of volatility predictors. AC.V Symposium Ser. 633 179-187. 

Springett, M.B., Rozier, V., and Bakker, J. 1999. Use of fiber interface direct mass spectrometry for the determination of volatile flavor release from model food systems. J. Agric. Food Chem. 47 1123-1131. 

Harrison, M., B.P Hills, J. Bakker, T. Clothier, Mathematical models of flavor release from liquid emulsions, J. Food Sci., 62(4), p. 653, 1997. 

Analytical methods involving exhaustive extraction of flavor compounds (i.e., liquid/liquid extraction, dynamic headspace) do not take these matrix effects into account. However, new instrumentation and methodologies are yielding improved information on the mechanisms involved in flavor/matrix interactions and the effects on flavor perception. For example, spectroscopic techniques, such as nuclear magnetic resonance (NMR), can provide information on complex formation as a function of chemical environment and have been used to study both intra- and intermolecular interactions in model systems [28,31]. In addition, NMR techniques, initially developed to study ligand binding for biological and pharmaceutical applications, were applied in 2002 to model food systems to screen flavor mixtures and identify those compounds that will bind to macromolecules such as proteins and tannins [32]. Flavor release in the mouth can be simulated with analytical tools such as the retronasal aroma simulator (RAS) developed by Roberts and Acree [33]. These release cells can provide... 

MS Brauss, RST Linforth, I Cayeux, B Harvey, AJ Taylor. Altering the fat content affects flavor release in a model yogurt system. J Agric Food Chem 47(5) 2055-2059, 1999. 

IS Ehnore, KR Langley. Novel vessel for the measurement of dynamic flavor release in real time from Uquid foods. J Agric Food Chem 44 3560-3563, 1996. IP Roozen, A Legger-Huysman. Models for flavor release in the mouth and its relation to new food product development. In ed. Chemistry of Novel Foods. 1997, pp... 

J Carr, D Baloga, JX Guinard, L Lawter, C Marty, C Squire. The effect of gelling agent type and concentration on flavor release in model systems. In RJ McGorrin, JV Leland, ed. Flavor-Food Interactions. Washington, DC American Chemical Society, 1996, pp 98-108. 

JX Guinard, C Marty. Time-intensity measurement of flavor release from a model gel system Effect of gelling agent type and concentration. J Food Sci 60 727-730, 1995. 

Interactions of flavor compounds with proteins are known to have a strong influence on flavor release from model foods [1], Proteins often cause a decrease in the volatility of flavor compounds. It is well known that proteins interact with volatiles both reversibly [2-3] and irreversibly [4-5]. 

Flavor release depends also on oil content, which affects the partition of aroma compounds during the different emulsion phases (lipid, aqueous, and vapor) [6]. In fact, lipids absorb and solubilize lipophilic flavor compounds and reduce their vapor pressures [7-8], as explained by mathematical models [9], headspace analysis [10], and sensory analysis [11 12]. 

The changes in flavor release with time (temporal release) under model mouth conditions were examined by PTRMS (Fig. 1). The maximal intensities of the compounds varied, but the time to reach this intensity did not differ significantly among the compounds. Ethyl acetate showed largest... 

M Harrison. Mathematical models of release and transport of flavors from foods in the mouth to the olfactory epithelium. In DD Roberts, AJ Taylor, eds. Flavor Release. Washington, DC American Chemical Society, 2000, pp 179 191. 

Burova TV, Grinberg NV, Golubeva lA, Mashkevich AY, Grinberg VY, Tolstoguzov VB. Flavor release in model bovine serum albumin/pectin/2-octanone systems. Food Hydrocolloid 1998 13(1) 7-14. 

During mastication, nonvolatile flavor molecules must move from within the food, through the saliva to the taste receptors on the tongue, and the inside of the mouth, whereas volatile flavor molecules must move from the food, through the saliva and into the gas phase, where they are carried to the aroma receptors in the nasal cavity. The two major factors that determine the rate at which these processes occur are the equilibrium partition coefficient (because this determines the initial flavor concentration gradients at the various boundaries) and the mass transfer coefficient (because this determines the speed at which the molecules move from one location to another). A variety of mathematical models have been developed to describe the release of flavor molecules from oil-in-water emulsions. 

More recently Veith [25] has completed a thesis on silicas as potential flavor delivery materials. She chose to prepare emulsions of model aroma compounds in water and then allow silica to form a matrix around the flavoring droplets. The ability to control silica structure allowed her to study the relationship between silica structure and performance. The concept of forming silica particles around flavorings is novel. She is in the process of publishing her results in the Journal of Agricultural and Food Chemistry and the Journal of Controlled Release. 

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