The scalping of aroma compounds causes the loss of aroma intensity and/or the change in aroma profile. This latter effect is explained by the different affinity that different aroma compounds, usually belonging to different chemical species, have for the plastic phase. A right approach in the study of scalping should consider the odor thresholds and odor activity values of volatiles in order to select those volatiles whose loss can determine a sensory effect. Moreover, the determination of sorbed volatiles directly from plastic gives more reliable results and information about the nature of the sorptive phenomenon with respect to the indirect determination of the loss of volatiles from the contact solutions. Researches focusing on the sorption of wine volatiles into plastic are lacking, and most studies addressing the scalping of aroma compounds have been focused on citrus volatiles. The aim of the present research was to evaluate Multiple Headspace Solid Phase Microextraction (MHS-SPME) as a method to study the sorption kinetics of two wine volatiles, namely ethyloctanoate and linalool, from a model solution into CPP and LLDPE. The aroma compounds were selected on the basis of their low thresholds and high odor activity values in wine. Results highlight a higher affinity of ethyloctanoate for the plastic phase and a higher sorptive power of CPP compared to LLDPE. The experimental data of volatiles sorption kinetics were satisfactorily fitted by a mathematical model based on Fick’s second law. The different sorption kinetics of ethyloctanoate and linalool determine different variations of the respective odor activity values, this results in an imbalance of the aroma character, which would be a factor limiting the shelf-life of wines packed in multilayer packagings. The study of the sorption of volatiles is a helpful tool in the choice and optimization of packaging materials which could preserve the original aroma composition of wines packed in plastic.
Study of the scalping of wine aroma compounds into plastic films / Licciardello, F; DEL NOBILE M., A; Spagna, G; Muratore, G. - (2008), pp. 6-6. (Intervento presentato al convegno SLIM 2008 -Shelf life International Meeting tenutosi a Ischia (NA) nel 25 - 27 giugno 2008.).