Effects of the nature and concentration of substrates in aqueous solutions on the solubility of aroma compounds

Abstract

The solubility of nine aroma compounds (acetone, 2-butanone, 2-hexanone, 2-octanone, ethyl acetate, ethyl butanoate, ethyl hexanoate, n-hexanal, and n-hexanol) in both water and various aqueous solutions was measured at 25°C using the mutual solubility method. The aqueous solutions consisted of sucrose, glucose, sorbitol, glycerol, polyethylene glycol 200, or maltodextrins at different concentrations. Aroma solubility in water decreased with increased hydrophobicity. For aroma molecules which have the same number of carbon atoms in their structure, aqueous solubility decreased as follows: aldehyde > > > > > methyl ketone > > > > > alcohol > > > > > ethyl ester. When using a group contribution method, the estimated solubility of ethyl esters and methyl ketones in water was, respectively, underestimated and overestimated. Compared to water, the solubility of the volatile molecules in aqueous solutions was higher in the aqueous polyols solutions than in the carbohydrate solutions, although solubility decreased as substrate concentration increased. Aqueous solutions properties, such as water activity, also influenced aroma compound solubility.

Rapid determination of partition and diffusion properties for salt and aroma compounds in complex food matrices

“…Indeed, comparing data available in the literature such a variation can be found. For example, air/water partition coefficient of ethyl hexanoate at 25°C varied from 0.21 Â 10 À2 (Covarrubias-Cervantes et al, 2005) to 3.01 Â 10 À2 (mean value of Lubbers et al (1993), Langourieux and Crouzet (1994), Jouenne, 1997;Voilley and Lubbers, 1997) corresponding to a 95% variation. The VASK method led to more reliable results than the PRV method as confidence intervals were smaller.…”

Influence of polyols and bulking agents on flavour release from low-viscosity solutions

“…Interactions between water -the predominant constituent of many foods -non-volatile food ingredients and flavour molecules have been widely studied and are characterised by the hydrophobicity (log P value) and volatility (gas-liquid partitioning coefficient, also known as Henry's law constant, k H ) of the latter (e.g., Philippe et al, 2003;Seuvre, Philippe, Rochard, & Voilley, 2007). The influences of different types of sugars on gas-liquid partitioning and consequently headspace concentration of flavour compounds released from aqueous carbohydrate solutions have been previously reported in the literature (e.g., Covarrubias-Cervantes, Bongard, Champion, & Voilley, 2005;Goubet, Le Quere, & Voilley, 1998;Hollowood, Linforth, & Taylor, 2002;Lubbers & Guichard, 2003;Nahon, Harrison, & Roozen, 2000;Rabe, Krings, & Berger, 2003;Roberts, Elmore, Langley, & Bakker, 1996). However, several earlier studies appear to contradict one another, showing both suppression and enhancement of flavour release in the presence of sucrose and other carbohydrates (e.g., Friel, Linforth, & Taylor, 2000;Hansson, Andersson, & Leufvén, 2001;Philippe et al, 2003).…”

Mixture design approach as a tool to study in vitro flavor release and viscosity interactions in sugar-free polyol and bulking agent solutions

“…Other studies have similarly reported a decreased flavor release in the presence of carbohydrates and hydrocolloids (Covarrubias-Cervantes, Bongard, Champion, & Voilley, 2005;Nahon, Navarro y Koren, Roozen, & Posthumus, 1998;Philippe et al, 2003). The lower t max value of cis-3-hexenol in the viscous matrix, as well as the very similar I max value compared to water, cannot yet be fully explained but may be related to a shift towards a more hydrophobic character of the aqueous solutions after adding polyols and bulking agents.…”