Correction of low values of gluten power (W value) due to the sunn pest attack

Abstract

Determining the quality of wheat-derived flours is influenced by some essential parameters. These parameters are wet gluten, index gluten, Falling Number and W-power from the alveoconsistograph analysis. The quality of the wet gluten represented by the power parameter (W) is directly influenced by the sunn pest attack. The sunn pest, scientifically called Eurygaster integriceps is a pest that can bring not only quantitative damages, but also qualitative ones. The sunn pest stings the grain during various developing stages and, with the saliva, it introduces an enzyme named protease. The gluten’s main components are gliadin and glutenin, the protease introduced at the same time with the saliva by this pest plays the role of dissolving the gluten’s bonds. The glutenin contributes to the dough’s resistance, firmness and extensibility, while the gliadin contributes to the dough’s elasticity. These components form a three dimensional skeleton within the dough’s mass prepared out of the wheat flour, conferring it all the bread making properties. As per W value, the minimum value considered suitable for bread making is 120, below this value we speak of the protease activity; the harder the attack, the lower the W value, and, implicitly, the increased protease activity. The presence of proteolytic activity leads to the change of the rheological features of the dough meaning the decrease in elasticity and the increase of extensibility. 100 tons of wheat were analysed and an average sample has been selected. This sample was analysed from the flour stage to the final bread product. The uncorrected sample was considered a witness sample. The witness sample was corrected with: ascorbic acid, glucose oxidase and lipase in order to follow the evolution of the W value. The correction was performed by the three separated components and then the synergic effect was followed. In parallel with the evolution of the quality parameters, the behaviour improvement of the bread-making process was followed as well.