Retention and Release Kinetics of Aroma Compounds from White Sauces Made with Native Waxy Maize and Potato Starches: Effects of Storage Time and Composition

Grażyna Bortnowska , Zuzanna Goluch

Abstract

Retention (R) of ethyl acetate (EA), hexanal (HE) and R-(+)-limonene (RL) in white sauces (WS) during 10-days refrigerated storage period was analyzed quantitatively using static headspace gas chromatography-mass spectrometry in relation to: starch type (waxy maize starch, WMS; potato starch, PS), starch concentration (2–5 wt%) and rapeseed oil (RO) content (3 or 9 wt%). The Avrami's equation was implemented to determine release rate constants (k) and release mechanism parameters (n). The enthalpy (ΔH) of aroma compounds (AC) affinity was calculated using van't Hoff's model, from the variations of equilibrium partition coefficients (kg/m) of AC, determined between the air (g) and matrixes (m) at temperatures ranged from 20 to 50 °C. The R values were significantly (p < 0.05) affected by both starch type (ST) and starch concentration (SC) and generally were greater in samples stabilized with PS than WMS, most probably due to the higher amylose content. Increase of RO amount, enhanced R values, particularly regarding HE and RL. Irrespectively of the ST, the k values showed descending tendency with raising SC and were higher for EA than for more hydrophobic AC (HE, RL). In all WS, the release mechanism was found to be controlled by molecular diffusion and the n values were in ranges: 0.59–0.82 and 0.56–0.81, in WS composed of 3 and 9 wt% RO, respectively. The magnitudes of ΔH related to the energy required for partitioning of AC from WS to the headspace, were greatly dependent on both AC properties and WS composition, particularly ST and SC.