MEETING ABSTRACT

P-356
Teflon and bronze shaped pasta: Is it only a matter of surface appearance? M. LUCISANO (1), M. Pagani (1), M. Mariotti (1), D. Locatelli (2). (1) DiSTAM (Department of Food Science and Microbiology), University of Milan, Milan, Italy; (2) Institute of Entomology, University of Milan, Milan, Italy.

Pasta dough that is formed in the kneading machine and then driven by the extrusion screw towards the head of the press is forced through the die whose characteristics strongly affects the appearance of the pasta surface. Traditional dies made entirely of bronze make the pasta surface rough, which helps to capture the sauce, whereas the Teflon insert gives the product an even surface and a smoother texture. To find out if other quality characteristics could be affected by die materials, pasta was prepared with semolina using two different size distributions and extruded through Teflon and bronze dies. Samples were dried at both high (maximum temperature: 90°C) and medium temperatures (maximum temperature: 70°C). The dried spaghetti was evaluated for its mechanical strength (bending test with an Instron Machine), porosity in terms of pore volume, size and distribution (Pascal 240 high pressure porosimeter), susceptibility to the infestation with Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and SEM ultrastructure of pasta surface before and during insect infestation. Results showed that pasta extruded through the bronze die presented a higher porosity (4.2% for fine semolina and 3.7% for coarse semolina versus 2.2% for samples extruded through the Teflon die) due to a higher number of pores larger than 1 µm. This characteristic caused a 20–30% reduction in the spaghetti breaking strength and a higher development of the insects as the surface of pasta made the deposition of eggs easier as demonstrated by SEM images that show an uneven and rough surface presenting numerous tiny pits. The size distribution of the semolina and the drying cycle influenced the spaghetti’s breaking strength and insect development, to a lesser extent.