Partition Coefficients For Acetates In Food Systems

Abstract

Flame-ionization gas chromatography was used to determine equilibrium partition coefficients for C 1-C 5 acetates at high dilution between air and water, aqueous solutions of various carbohydrates, vegetable oils, and mineral oil. A modified sampling and injection technique was used to overcome sorption effects for vapor samples. Measurements were made over a range of temperatures from 25-50 °C. Partition coefficients between air and solutions of sucrose, maltose, and dextran (M r 90 000) increased sharply with increasing dissolved-solids content. For the disaccharide solutions this could be attributed qualitatively to a loss of free water due to hydration of sugar molecules. For solutions of maltodextrin, dextrin, and coffee solids, the acetates were held into solution more at the higher dissolved-solids contents, and the partition coefficient for pentyl acetate actually decreased with increasing concentration of dissolved solids. Partition coefficients between air and the oils were much lower and indicated an activity coefficient of about 0.7 for the acetates in coffee and peanut oils. © 1979 American Chemical Society.27350450