High correlation between octanol-air partition coefficient and aroma release rate from O/W emulsions under non-equilibrium

Abstract

Aroma release kinetics determines the palatability of food consumed by humans. Therefore, to estimate release behaviors of aroma compounds is important. We investigated the relationship between the rates of the release of aroma compounds from food matrices and octanol-water, octanol-air, and water-air partition coefficients. The aroma compounds used were limonene, ethyl hexanoate, 2-methylpyrazine, nonanal, benzaldehyde, ethyl benzoate, α-terpineol, geraniol, benzyl alcohol, and octanoic acid. The rates of their release from oil-in-water (O/W) emulsions were measured under non-equilibrium conditions using a purge-and-trap dynamic headspace extraction system. The results indicated that the octanol-air partition coefficients correlated better with the logarithms of the aroma compound release rates than either the octanol-water or the water-air partition coefficients. Furthermore, this correlation was independent of the oil volume ratios in the O/W emulsions. Our findings therefore suggest that octanol-air partition coefficients can be used to predict the release rates of aroma compounds from O/W emulsions.

Keywords: Aroma; Emulsion; Partition coefficient; Release rate.