Relationships between wheat flour baking properties and tensile characteristics of derived thermoplastic films

This work was aimed at defining models to explain tensile properties of thermoplastic films derived fromcommon wheat flours as a function of source flours characteristics. A total of 26 flours, two blends from anindustrial mill and 24 single-cultivar flours collected over three different years of grain production (from2013 to 2015) and cultivar grain hardness (from soft to hard) were used in a wide range of protein content(from 9.0 to 16.2%) and values of Chopin’s alveograph parameters (as indexes of gluten characteristics),i.e., P (from 27 to 160 mm), L (from 32 to 236 mm), P/L (from 0.13 to 4.44), and W (from 63 to 398). Thesame plasticization recipe and filming procedure was adopted for all manufactures. The maximum tensilestrength (max) and the elongation at break (εmax), as well as the elastic modulus (E), stiffness (k) andenergy at break (wb) of films from flours having moderate to high values of P (>60 mm), P/L (≥0.43) andW (>170) were positively correlated to P and negatively correlated to P/L and W, with all the variablessignificant (p-value <0.05) and R2= 0.72 for max, 0.62 for εmax, 0.81 for E, 0.83 for k and 0.72 for wb.The εmaxof films obtained from flours having moderate to low values of P (≤45 mm), P/L (≤0.42) and W(≤160) was negatively correlated to P, L and P/L, and positively correlated with W, with all the variablessignificant (p-value <0.05) and R2= 0.86. On the contrary, no relationship was found for the max, as wellas for E, k and wbof these films. Results encourage further research aimed at improving the robustnessand reliability of models so that tensile properties of a thermoplastic film can be predicted for any givensource flour.©