Fac-simile Scheda Linee di Ricerca - Federalimentare

5. Mariotti, M., Lucisano, M., Pagani, M.A., Fongaro, L. (2006). About puffed cereals and theiruse in breadmaking. World Grains Summit: Foods and Beverages, San Francisco, California,U.S.A., September, 17-20.Puffed cereals are commonly used as ready-to-eat breakfast foods or as ingredients in snack formulations; theyare appreciated mainly for their lightness and crispness, qualities related to their cellular structure and degree ofexpansion. Since few investigations have been made on puffed cereals and on flours milled from them, the aim ofthis study was to evaluate the changes associated with the puffing process as applied to three different grains(common wheat, rye and rice) and to investigate their use in a breadmaking. The samples were evaluated as regardsultrastructure and chemical-physical properties. The morphology and composition of the kernel strongly affectedthe characteristics of puffed products. In fact puffed rye and rice showed a very porous matrix, whilepuffed wheat had a much more compact and homogeneous structure (as evaluated by SEM). At the macromolecularlevel, the puffing treatment induced significant changes in the physical properties of starch, which causedan increased water holding capacity of grains and flours. The puffed flours were then added at different levels(from 1 to 7%) to wheat flour of good baking characteristics and the resulting mixtures, after being characterizedfrom the rheological point of view, were baked using a straight-dough method. The resulting breads were evaluatedafter baking and during storage at controlled conditions. The results suggest that flours from puffed cerealscan be used not only as ingredients in snack formulations, but also as a good means for controlling water migrationin baked products: the use of low amounts of puffed flours (3% maximum), in fact, slowed bread staling andthe product remained softer for a longer period.6. Mariotti, M., Pagani, M.A., Lucisano, M., Iametti, S. (2006). Rheological and structural propertiesof wheat dough acidified by means of a chemical or a biological procedure. 3 rd InternationalSymposium on Sourdough, Bari, Italy, October, 25-28.Sourdough is the microbial inoculum for many typical Italian baked products. Sourdough fermentation producesa slow acidification due to the progressive production and accumulation of microbial metabolites that induce peculiararomatic properties and enhance the shelf-life of the product. The effects of the acidification on the structuralorganization of starch and protein macromolecules are less known. The influence of the acidification (pHrange from 5.9 to 4.0), obtained by two different procedures (sourdough process or addition of lactic acid), on thestructural and rheological properties of the dough was investigated by means of empiric and fundamental tests.The chemical acidification promotes a progressive decrease of the dough consistency and elasticity, pointed outby the farinographic test. The “weakening” of the protein network is confirmed by a lower storage modulus (G’),evaluated by the frequency sweep test. Moreover, the rheofermentographic test shows a decrease in dough volumeand CO 2 retention. Other changes related to pH can be observed in starch behaviour during the viscoamylographictest.The biological acidification induced by the sourdough process promotes changes in the protein organization aswell. Nevertheless, the front face fluorescence approach underlines the network capacity to maintain a morecompact structure even at low pH values. These results indicate that the slow and progressive dough acidificationassociated with the biological process allows the proteins to organize a network that is more suitable for guaranteeinga higher volume expansion.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.it209