Emulsion-based control of flavor release profiles: Impact of oil droplet characteristics on garlic aroma release during simulated cooking.

The objective of this research was to elucidate the main factors influencing flavor retention in oil-in-water emulsions during simulated cooking, including oil droplet concentration, oil type, droplet size, and emulsifier type. Allyl methyl disulfide (AMDS), a hydrophobic flavor in garlic that is easily lost from foods during processing, storage, and preparation, was used as a model aroma compound. The impact of droplet characteristics on the flavor retention profile of AMDS-loaded emulsions subjected to simulated cooking conditions was determined, which involved heating from them from room temperature to boiling and then holding them for 30 min. The flavor retention half-time (FT1/2) was calculated from the retention-time curves, i.e., the time for the flavor concentration to decrease to half its initial value. Based on FT1/2, the flavor retention during cooking depended on oil type: palm oil > corn oil > mineral oil. However, the mineral oil emulsions were also the most unstable to droplet coalescence during cooking. Increasing the oil droplet concentration in the emulsions increased flavor retention during cooking, but also decreased their physical stability. Based on FT1/2, the type of emulsifier used to formulate the emulsions also influenced flavor retention: quillaja saponin > Tween 80 > sodium caseinate > whey protein isolate. The emulsions that were most unstable to coalescence during cooking, and therefore had the largest droplet sizes, tended to have better flavor retention (longer FT1/2). The observed differences in flavor retention were mainly attributed to differences in the size and location of the oil droplets during cooking. These results have important implications for the design of food matrices that can control flavor retention and release during food preparation.