Quality and quantity of gluten in commercial wheat flours used in the bakery industry in Peru

Wheat (Triticum aestivum L.) is part of the basic consumption of the Peruvian population, but its production is deficient. Wheat cultivation is used for the production of farinaceous products; however, it does not cover the internal demand that annually amounts to 2 million metric tons of wheat, being supplied mainly by imports (around 90% of the total). The objective of this study was to evaluate the quality and quantity of gluten in commercial wheat flours used in the Peruvian bakery industry. Physicochemical and rheological properties were evaluated in 14 commercial wheat flours from Peru. Moisture, ash, fat, and protein were determined according to AOAC methods 925.10, 923.03, 922.06, and 920.87, respectively. Wet gluten, dry gluten and gluten index, as well as the falling number, were evaluated according to the AACC 38-12 and AACC 56-81 methods, respectively. The correlation between the different variables was performed using the Pearson method (p≤0.05). According to our results, the moisture, ash, fat and protein content of wheat flours ranged from 13.00 and 14.42%, 0.39 to 1.38%, 0.56 to 1.55% and 8.51 to 12.72%, respectively. Regarding the quality of the gluten protein, the levels of wet gluten, dry gluten and gluten index varied between 22.59 to 37.60%, 7.20 to 12.29% and 86 to 99%, respectively; while the falling number ranged from 295 and 483 s. Wet gluten was significantly correlated with the content of protein and dry gluten (r=0.857 and r=0.970, respectively; p≤0.01), as well as with the falling number (r=-0.381, p≤0.05). Gluten index was significantly correlated with the moisture and falling number (r=0.527 and r= 0.739, respectively, p≤0.01, Table 1). Our results suggest that the quality of gluten in commercial wheat flours is associated with the moisture content and falling number, while the amount of gluten is associated with the protein content of commercial wheat flours.