The effects of the kneading and forming process or pasta quality have been investigated. Using the same blend of wheat flour and keeping mixing and drying conditions constant, three types of spaghetti were produced using the following three kneading and forming processes: A) kneading with a continuous press and forming by pressure-extrusion; B) kneading and forming by sheeting-rolls; C) kneading by hand and forming with sheeting-rolls. These three processes impart different mechanical work on the dough.
The three types of dried spaghetti exhibited differences in cooking requirements and in cooing quality. Spaghetti (A) absorbed water more slowly and showed poor cooking quality. Spaghetti (B) and (C) had a shorter cooking time, no stickiness and good firmness after cooking. Spaghetti compactness seems to control water absorption during cooking, i.e., the greater the compactness, the longer the cooking time. Nevertheless, compactness does not explain differences in cooking quality. On the contrary, this characteristic is clearly related to the different organization of proteins, as transmission and scanning electron microscopy images revealed. In fact both spaghetti (B) and (C) showed a compact and continuous protein network, probably as a consequence of the mild and ordered kneading obtained by the sheeting process. Spaghetti (A), produced by dough kneading implying strong mechanical stresses, exhibited protein network breakage which may account for its poor cooking quality.
The results of the present work indicate that industrial kneading and extrusion, as performed today in the continuous press, are unsuitable for making the best use of poor quality raw materials. The pressure-extrusion process requires technological innovations which could ensure spaghetti with cooking quality comparable to that produced in the traditional sheeting process as well as high productivity.
Pagani, M. Ambrogina; Resmini, Plerpaolo; and Dalbon, Gerardo
"Influence of the Extrusion Process on Characteristics and Structure of Pasta,"
Food Structure: Vol. 8
, Article 2.
Available at: http://digitalcommons.usu.edu/foodmicrostructure/vol8/iss2/2