Physicochemical, technological and antioxidant characterization of wheat processing by-products – wheat bran, sweep flour and grain mixture

Wheat is an important cereal for humans due to its energy component, mainly starch, and versatility in many food applications. During its processing, some by-products are co-produced, reaching about 150 million tons of wheat bran per year. The objective of this study was to characterize the physicochemical, technological and antioxidant properties of three wheat by-products (Triticum spp.) (SPT), wheat bran (FT), sweep meal (FV) and grain blend (MG), as sustainable sources of polysaccharides for various applications. Moisture, ash, lipids, proteins, carbohydrates, fibers, water activity (A_w), fatty acidity, color and reducing sugars were determined. Thermogravimetric analysis (TGA) and infrared spectroscopy (FTIR), bulk density, water and oil absorption, solubility and inflaming capabilities, and Rapid Visco-Analyzer (RVA) were used to evaluate the technological behavior of the SPT. Folin-Ciocalteu reagent and equivalent antioxidant capacity of Trolox using ABTS were used to evaluate the antioxidant properties. The moisture content ranged from 10.4 to 12%, while the A_w ranged from 0.55 to 0.71 in MG, FT and FV, respectively. FT had the highest fiber content, followed by MG and FV, while the protein content was similar, 17.3-18.6%. FT showed an onset temperature in TGA at 268.5 °C, while FV and MG at 289 °C. The FTIR spectra revealed that FT had higher intensity bands associated with cellulose, lignin, and hemicellulose, while FV showed bands related to starch and lignin, and MG presented bands linked to polysaccharides and lipids. Rapid Viscosity Analyzer (RVA) pasting properties showed that FV had the highest viscosity peak, 2957.7 cP, followed by MG, 717.3 cP, and FT, 213 cP, while the gelation temperature was approximately 80.8 °C for MG, 68.5 °C for FV, and 0 °C for FT. Antioxidant assays revealed that MG exhibited the highest activity, followed by FT and FV. These results suggest the potential of using SPT as a sustainable resource for obtaining polysaccharides and fibers for various applications, such as the development of biodegradable functional coatings.