Modelling the effects of transglutaminase and l-ascorbic acid on substandard quality wheat flour by response surface methodology

Abstract

Over the past decade, extreme variations in climatic conditions have been observed, which in combination with inadequate agro techniques lead to decreased quality of mercantile wheat, i.e. flour. The application of improvers can optimise the quality of substandard wheat flour. This paper focuses on systematic analysis of individual and interaction effects of ascorbic acid and trans-glutaminase as dough strengthening improvers. The effects were investigated using response surface methodology. Transglutaminase had much higher linear effect on the rheological and fermentative properties of dough from sub-standard flour than L-ascorbic acid. Both transglutaminase and L-ascorbic acid additions had a significant linear effect on the increase of bread specific volume. Effects of transglutaminase and ascorbic acid are dependent on the applied concentrations and it is necessary to determine the optimal concentration in order to achieve the maximum quality of the dough and bread. Optimal levels of tested improvers were determined using appropriate statistical techniques, which applied the desirability function. It was found that the combination of 30 mg/kg of transglutaminase and 75.8 mg/kg of L-ascorbic acid achieved positive synergistic effects on rheological and fermentative wheat dough properties, as well on textural properties and specific volume of bread made from substandard quality flour.