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4. Piazza L., Gigli J., Ageno, M. 2007. Interfacial shear rheology study of wet foams. In: CIGRSection VI – 3 rd International Symposium Food and Agricultural Products: Processing andInnovation, p.86 e [CD rom]. PPf2/4.The texture and the persistence of the wet foam of tiny sphere-shaped gas bubbles that tops the espresso coffeeliquid phase are of the utmost importance for the quality of this brew. The prevailing liquid phase of the wetfoam solubilizes biopolymers and natural surfactants which will participate to the formation of the liquid filmsframing the gas phase. The rheology of the interfacial layer can potentially contribute to stability and functionalityof foam. This work follows a previous published paper (Piazza, Gigli & Bulbarello, 2007) in which the mainmacromolecules responsible for the espresso coffee foaming fraction, i.e. proteins/melanoidins complexes fractionand polysaccharides fraction were extracted from defatted and non-defatted commercial coffee powders andanalyzed for their foaming attitude and interfacial viscoelastic properties. The development of interfacial viscoelasticdynamic moduli at the liquid/gas interface was monitored by means of a commercial interfacial rheometer.In this paper the rheology data are completed with tensiometric measurements (pendant drop technique) and amathematical evaluation of the phenomena underlying the viscoelastic properties is suggested. The interfacialelastic modulus increases with time in a sigmoid-like mode and contains the particle coagulation kinetic, governedby Smoluchowsky equation, and the migration of particles from the bulk phase to the interface. Due to thecomplexity of the system, an appropriate mathematical description is here presented that overcomes some limitationsof the existing models and describes the development of interfacial viscoelastic properties at the liquid/gas interface on long observation scales. The proposed model contains a linear term of transport and the kernelfunction (considering the simplest case of hard rigid spherical particles in brownian motion), integrated in onedifferential equation to describe the coagulation and migration of particles to the interface.5. Piazza L., Gigli J., Arecchi A. 2007. Release of nano-encapsulated flavour compounds in designedfood gels. In: CIGR Section VI – 3 rd International Symposium Food and AgriculturalProducts: Processing and Innovation , p.233 e [CD rom]. P/22.In spite of the advances in flavour research, the prediction and control of flavour performance in complex foodsystems is still limited. In recent years, an aspect is receiving a growing attention: the structural organization ofthe food matrices in relation to flavour binding, release and flavour perception. The perception of the release of alipophilic aroma compound widely used in food and non-food fields, R-(+)-limonene, was evaluated in this workby means of an electronic nose when using agar gel as encapsulating medium. Stability in encapsulation isreached if the aroma does not show a tendency to migrate from a phase to the other. Encapsulation and/or nanoencapsulationare successful solution to the problem. To that purpose, in this work cyclodextrins (CD) were usedas emulsion stabilizers: CD were enclosed in the system where they act as the shell material protecting limonene.The expected functional properties were achieived due to cyclodextrins hydrophobic nano-cavity and hydrophilicexternal surface. CD-flavour complexes were included in the gel phase. Agar gels were produced atdifferent concentrations ranging from 0.2 to 1% (w/v). Mechanical and rheological properties of the soft materialswere evaluated. The perception of the flavour release from the agar/limonene systems was quantified bymeans of the electronic nose: the results of tweak evaluations are here presented. The cyclodextrin/limonenecomplexation was carried out according to the paste method. Few preliminary results of the analytical gascromatographichead space analysis of the CD-mediated aroma release are finally presented, showing the considerableeffect of the cyclodextrins as emulsifying agents.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it224