Tocols stability during bread, water biscuit and pasta processing from wheat flours

Abstract

The evolution of tocol content was investigated during the manufacture of bread, water biscuit and pasta from refined flours of einkorn wheat, bread wheat and, for pasta only, durum wheat semolina. Total tocol content decreased throughout the processing stages. In bread and water biscuit, the kneading step led to relevant degradation (on average, 21.4 and 28.2%, respectively), while bread leavening and baking had almost negligible effects. In pasta the long kneading phase determined high losses (44.2%), while the extrusion step led to an average decrease of 3.7% under vacuum and of 29.7% with no vacuum; the drying step did not induce significant changes. Considering the production processes from inception to conclusion, average tocol losses were: in bread 24.1% and 25.4% (crumb and crust, respectively), in water biscuits 25.3% and in pasta 41.0% (under vacuum extrusion) and 55.7% (no vacuum). In spite of a significant decrease, einkorn showed better preservation and supplied more tocols in the end products than durum and bread wheats: on average, in pasta tocol content was 20.4 vs. 8.2 vs. 5.3 mg/kg DM, respectively, while in bakery products (bread and water biscuits) was 20.9 (einkorn) vs. 10.4 mg/kg DM (Blasco).