45C-19 |
Influence of emulsifying agent on aroma release in model oil/water emulsions |
D. G. PETERSON, J. N. Coupland, L. A. Dalby, and S. L. Schwambach. Dept. of Food Science, Pennsylvania State Univ., 215 Borland Lab., University Park, PA 16802-2505 For many foods and beverages, the fat phase occurs as part of an emulsion. Various emulsifying agents are commercially available, each with different physico-chemical properties. Hence, it was thought emulsifier-type might have a significant impact on the aroma release profile in foods and beverages (flavor perception) due to differences in their chemical reactivity and diffusion properties. The objective of this study was to evaluate the influence of emulsifier-type on the release of select aroma molecules in model o/w emulsions. A novel instrumental design was developed for the analysis of aroma molecules released from model o/w emulsions. This design consisted of a model mouth which was directly interfaced to a flame ionization detector (FID). Time-release profiles for several aroma compounds (aldehydes, esters and ketones) were obtained from o/w emulsions (median particle diameter of 0.5 m) using three emulsifying agents (whey protein isolate, Tween 20 and gum arabic). Static headspace analysis with gas chromatography was also used to quantify the concentration of the 'free' aroma compounds in the model o/w emulsions. Time-release profiles showed that emulsifier-type had a significant effect on aroma release kinetics in o/w emulsions. The release from certain aroma-surfactant combinations (e.g., whey and hexanal) was particularly slow suggesting chemical binding which was also supported by static headspace analysis. This work indicated that selection of emulsifying agent can serve as an important parameter for controlled release of aroma molecules in o/w emulsions.
Session 45C, Food Chemistry: Flavor and aroma chemistry
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