Characterization of Iraqi Domestic Wheat Flour and the Correlation between Chemical and Rheological properties

Abstract

Iraqi domestic wheat quantity increased dramatically during the last two years, and the Iraqi government is looking for self-sufficiency in wheat production. However, the quality of the wheat flour is more important than the quantity in terms of making the final product. Therefore, this study aimed to determine the quality of Iraqi domestic wheat. Also, the study aimed to conduct the correlation between the chemical and rheological properties of flour samples. The study included 29 flour samples. The results showed that protein content was 10.2 ± 0.4%, gluten content was 19.6 ± 5.0%, gluten index was 73.2 ± 29.8%, and the falling number was 610 ± 89s. Rheological properties were ranged from 1.8 to 9.5min for the stability, 50 to 260BU for the degree of softening (DoS), zero to 78cm2 for the energy, and 4 to 220mm for the extensibility. The highest correlation was between the gluten index and the Farinograph and Extensiograph parameters. Gluten index was highly correlated to DoS (r = -0.87, p < 0.0001), followed by extensibility (r = 0.76, p < 0.0001), stability (r = 0.72, p < 0.0001), and energy (r = 0.66, p < 0.0001). The correlation between other studied chemical properties, protein and gluten content, and most rheological parameters was non-significant. In conclusion, Iraqi domestic wheat quality was varied, from very runny to moderate. The gluten index was a precise parameter can be used to predict wheat quality. Therefore, Iraqi wheat breeders should be strongly considered the wheat quality in their work in addition to the quantity.