We use pressure-variable differential scanning calorimetry to detect and characterize thermally induced transitions (glass, melting, gelatinization) in pre- and post-extruded wheat flour. The resulting data allow us to construct a two-dimensional state diagram which maps the physical states that pre- and post-extruded wheat flour can assume, at constant pressure, as a function of moisture content, temperature, and the specific mechanical energy, SME, generated in the extruder. We describe how this state diagram can be used to map the path of extrusion processing, to assess the impact of extrusion conditions, and, ultimately, to design formulations and processing conditions that result in desired end-product attributes. For the extrudates, we find that the extent of processing-induced fragmentation, as monitored by reductions in the extrudate glass transition temperature,Tg, increases with the SME generated in the extruder. We demonstrate that a wheat-flour state diagram, which includes the glass curve of the wheat-flour extrudates produced at various SME values, allows one to predict and control the impact of processing conditions on extrudate properties.
Authors:A. Okrajková, M. Prieto-Linde, Z. Muchová, and E. Johansson
Antes, S., Wieser, H. 2000. Quantitative determination and localization of thiol groups in wheatflour. In: Shewry, P.R., Tatham, A.S. (eds), Wheat Gluten. Cambridge, UK: The Royal Society of Chemistry, pp. 211
. Even though PS did not show any significant public health issues, studies demonstrated that PS should be used with precaution ( Mamur et al., 2010; Carocho et al., 2014 ). Accordingly, this study aimed to analyse the potential of fermented wheatflour
Batey, I. L., Gupta, R. B. and Mac Ritchie, F. (1991): Use of size-exclusion high-performance liquid chromatography in the study of wheatflour proteins: An improved chromatographic procedure. Cereal Chem. 68 , 207-209.