Pasteurized fresh egg pasta: dependence of structural and cooking properties on heat treatment intensity

According to Italian law, packaged fresh egg pasta must undergo a thermal treatment at least equivalent to pasteurization. Manufacturers usually apply a double thermal treatment, the first on loose pasta and the second on packaged product. The aim of this work was to evaluate cooking behavior and mechanical properties of fresh egg pasta as a function of the applied thermal treatment intensity expressed as C0. Eighteen samples of fresh egg pasta were produced in an industrial plant as sheets for “lasagna”. Of these, one did not undergo any thermal treatment, one was only pasteurized as loose pasta (95°C for 1.5 min) and the remaining 16 samples underwent, after packaging, a second treatment in static cells at 70°, 83°, 88° and 93°C, for four different resting times ranging from 60 to 90 min. For each pasteurization treatment, the C0 value was calculated using a z value referred to the formation of Maillard reaction product in fresh egg pasta. All samples were characterized by furosine level, cooking behavior (matter loss in cooking water and pasta weight increase), and mechanical parameters of cooked pasta (break load, break strain and Young modulus). The increase of pasteurization treatment severity causes a proportional reduction of both matter loss (p<0.01) and weight increase (p<0.01), suggesting a progressive strengthening of protein network that hinders the water accessibility and the swelling of starch granules. Tensile tests on cooked sheets showed that pasta toughness and hardness, expressed as break load and Young modulus, increase with C0, whereas extensibility (break strain) decreases. These results demonstrate the major role of pasteurization treatment intensity on the strengthening of fresh egg pasta protein matrix, leading to a better structure and cooking behavior. Thus, at given formulation and packaging conditions, the use of more severe pasteurization treatments, aimed to extend shelf-life, also has a structuring effect on fresh egg pasta.