Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1. Piazza, L., Gigli, J., Rojas, C., ; Ballabio, D., Todeschini, R., ; Tripaldi, P. 2009. Dairy creamresponse in instrumental texture evaluation processed by multivariate analysis. Chemometricsand Intelligent Laboratory Systems 96, 258-263.The purpose of the present work is to highlight potentiality of chemometric interpretation of consolidated instrumentalfood texture evaluations. In this study, back-extrusion tests were carried out on industrial-madewhipped dairy creams. Mechanical profiles were obtained from 0 up to 49 storage days and were analyzed byconsidering the signal as a whole using basic chemometrics tools. In order to obtain the maximum content of informationrelated to the mechanical properties of the dairy cream samples, the texture information carried on bymechanical profiles were quantified in terms of Principal Component Analysis. A threshold in whipped creamsshelf life was identified in terms of overall textural attributes and was equal to around 28 and 35 storage days,where a relevant variation of the mechanical properties was observed. Multivariate classification furnished objectiveand quantitative criteria for the shelf life mapping of the product, based on mechanical signals. Multivariatestatistical analysis proved to be able to handle large datasets produced by a consolidated analytical techniqueand consequently appeared as a promising tool for studying the entire mechanical profiles.2. Piazza, L., Gigli, J., Benedetti, S. 2008. Study of structure and flavour release relationships inlow moisture bakery products by means of the acoustic-mechanical combined technique andthe electronic nose". Journal of Cereal Science 48: 413-419.A combined acoustic-mechanical technique was employed to simultaneously characterise in uniaxial compressionmode the texture properties of commercial toasted sliced breads and laboratory-made ones that were madeby modifying the amount of sucrose in the recipe. Also an Image Analysis technique was used to describe themorphology of the gas cells. The analysis of the flavour release was performed by means of a commercial electronicnose system. Advanced techniques of multivariate statistical analysis were employed to get the maximuminformation from the proposed instrumental techniques. Some selected mechanical parameters and flavour releaseresponses are dominant in discriminating sliced bread samples and both express similar information. TheRegularised Discriminant Analysis output for the acoustic, mechanical and flavour release data was: Non ErrorRate Cross Validated equal to 80.1% in the cross-validation mode. The NERCV % index is an estimation of thepredictive potential of the model that was validated according to the leave one out (LOO) method. The LOOprocedure removes each sample from the data set, one at a time. The classification model is rebuilt and the classof the removed sample is predicted by using the obtained model. By combining these instrumental characterisationmethods, the result of the texture/aroma description of these cellular solids was improved.3. Piazza, L., Gigli, J and Ballabio, D. 2008. On the Application of Chemometrics for the studyof Acoustic-Mechanical properties of Crispy Bakery products.. Chemometrics and IntelligentLaboratory Systems 86: 52-59.Crispness is a salient textural property for most fresh and dry food products. Its loss, due to the adsorption ofmoisture, is a major cause of rejection by consumer. Crispness is related to food structure and its mechanicalproperties by the capability to generate an appropriate sound during mastication and to dampen or amplify thissound. The perception of crispness is therefore a simultaneous response to mechanical and acoustic stimuli. It isknown that an objective instrumental acoustic-mechanical combined technique for texture analysis of food productscan supply useful information on the structure of crispy products, but new methods to interpret the relevantinformation content of the instrumental response are required, in order to integrate traditional data analysis. Multivariateanalysis appears ideal for studying this kind of data and to our knowledge has never been applied oncombined acoustic-mechanical measurements. In this work, acoustic-mechanical properties of sliced toastedbreads were analysed by means of chemometric tools, such as Principal Component Analysis and DiscriminantAnalysis. Final results proved that multivariate analysis is able to extract relevant information and offer an easyand promising approach for the interpretation of instrumental food texture attributes.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.it226