Air—water partition coefficients of some aldehydes

Abstract

The air-water partition coefficients of a series of aldehydes from propanal to decanal in dilute aqueous solution have been measured by gas chromatography. The coefficients did not vary appreciably over the whole series, in contrast to the decreasing vapour pressures of the pure solutes. IntroductionThe aroma of a food is due to the small concentration of volatile compounds in the atmosphere above the food. The concentration of a compound in the atmosphere is controlled by a partition of the volatile compound between the food itself and the air above the food. Since most foods contain 50-go7~ of water it might be expected that this would largely be an air-water partition. A study has therefore been made of the air-water partition coefficients of some normal homologues from C, to C,, at 25" and atmospheric pressure.The concentrations of the aldehydes in the air-and the water-phase were determined with a gas-liquid chromatography (GLC) apparatus equipped with dual flame ionisation detectors.

Headspace Solid-Phase Microextraction Method for the Study of the Volatility of Selected Flavor Compounds

“…As the volatile compound in the system distributes between the air phase and the water until equilibrium has been reached, the concentration in the solution can be calculated from the initial volatile concentration, the volume of the headspace, V HS , and the volume of the solution, V water (eq 2) Using this procedure, the partition coefficients between headspace and water ( K HS/water ) measured in this study were comparable to those obtained in previous studies ( − ).…”

Partition ratios of some wood smoke phenols in two oil: water systems

“…Nelson and Hoff (1968) utilized a differential headspace analysis technique to determine the partition coefficients (Kp) of some volatile food components in a water ¡paraffin oil system. Buttery et al (1965) used gas chromatography to analyze the liquid and vapor phases in a study of the volatilities of some aldehydes, ketones, and esters in dilute water solutions. From this information the air-water partition coefficients were calculated.…”

Interaction of aroma compounds with food matrices

“…Most Table 13.1 Air/water and air/oil partition coefficients at 25 C (Buttery et al, 1965;Guichard, 2006;Landy et al, 2007) of the proteins used as food ingredients for different applications (such as gelation, thickening, emulsification and foaming) adopted a globular structure that results from an equilibrium between physico-chemical parameters including hydrophobic interactions, electrostatic interactions, hydrogen bonding, van der Waals forces and configurational entropy (McClements, 2002). The structure tends to reduce the contact area between non-polar groups and water and, for this reason, the main driving force stabilising the compact structure of globular proteins is related to hydrophobic interactions.…”