Investigation of sorption isotherms of wheat germ for its effect on lipid oxidation

Changes in Lipid Metabolites and Enzyme Activities of Wheat Flour during Maturation

The maturation of wheat flour is a transformative process that elevates its processing and culinary attributes to their peak performance levels. Despite extensive research on starch and gluten protein modifications, the impact of lipid changes has been largely unexplored. This study addresses this gap by examining the maturation of freshly milled wheat flour at 15 °C, 25 °C, and 40 °C over 60 days, focusing on enzymatic activities-lipase, lipoxidase, and catalase-and lipid metabolites, including free fatty acids, conjugated trienes, p-anisidine value, and total oxidation value. The results of this study showed that free fatty acids continued to increase at all temperatures, with the most significant increase of 50% at 15 °C. The p-anisidine value followed a pattern of initial increase followed by a decline, while conjugated trienes were markedly higher at 40 °C, suggesting temperature's significant influence on lipid peroxidation. Notably, total oxidation values became erratic post 30 days, indicating a shift in oxidative dynamics. This study underscores the correlation between lipid metabolites and enzymatic activities, revealing the enzymes' pivotal role in lipid oxidation. The interplay of temperature and time offers valuable insights for optimizing wheat flour maturation, ensuring superior quality for various applications.

Process optimisation of defatted wheat germ protein extraction in a novel alkaline-based deep eutectic solvent (DES) via Box-Behnken experimental design (BBD)

This is the first study to provide a preliminary investigation into the recovery of protein from wheat germ and the prediction of their extraction conditions in microwave cavity using a novel DES solvent. The response surface methodology was used to predict the microwaved protein extraction conditions of the DWG. The effects of DES buffer-concentration (X₁: 0.01-1.00 g/mL), microwave power (X₂: 50-250 W), irradiation time (X₃: 1-5 min) and sample-to-buffer ratio (X₄: 1:10-1:50) were tested using a single factor and Box-Behnken experimental design. Under the optimized conditions (X₁ = 0.52 g/mL, X₂ = 186 W, X₃ = 3.28 min, and X₄ = 1:39) protein yield and absorbed microwave were obtained at the optimal value of 33.00 % and 677 J/min, respectively with no denaturation of the protein as validated from the SDS-PAGE gel electrophoresis profile. Consequently, this investigation provides a practical approach for the extraction of bioactive protein from DWG using a novel deep eutectic solvent.