Transfer across goatskin barrier of 2-butanone, 2,3-butanedione and 2-butanol during maturation of traditional Lebanese cheese, Darfiyeh : Comparison between experimental aqueous model solution and goatskin system

Abstract

Darfiyeh cheese is a Lebanese traditional variety made from raw goats milk and ripened in goatskin. Ripening tools and conditions play the role of a barrier to protect the foodstuff against deterioration. This function requires the control of small volatile molecules transfer, such as aroma compounds. Several methods have been used for the measurement of diffusion of aroma volatile compounds. Few selected aroma compounds have been employed in more or less complex food model systems. Aqueous models containing some of the food components have been adopted as appropriate models given the complexity of food matrices. In this study, we characterized fragments of goatskin microbiologically, physico-chemically and qualitatively. Furthermore, we followed the transfer of three model aroma compounds (2-butanone, 2,3-butanedione and 2-butanol) in an experimental aqueous model solution/goatskin system at 20, 40 and 60 days of exposure. The barrier properties of goatskin were assessed for aroma model molecules through permeability and sorption tests. Therefore, the behavior/distribution of diffusing molecules was discussed on the basis of the physico-chemical properties of these molecules, the properties of the barrier material, as well as the food matrix (aqueous dilute model solution in the case of our study). Until 40 days, the transfer of model molecules was dependent on their physico-chemical properties and exposure time. After 60 days, the molecules tended to migrate from the goatskin back to the aqueous dilute model solution. In such a model, there was evidence of a tendency towards the diffusion of aroma model molecules in a cyclic way.