Effect of two amorphous silica powders on the physio-mechanical properties of hard red spring wheat over time

The growing awareness among consumers regarding chemical-free food consumption has driven the popularity of diatomaceous earths. While research on their efficacy for stored product protection is on the rise, the widespread adoption of diatomaceous earths as grain protectants is limited due to their negative impacts on treated grain physical properties. This study explores the effects of two amorphous silica powders from Imery's, Lompoc, CA, USA, designated as 1 and 2, on the physical properties and flowability of wheat grains. Wheat grains treated with 0.35 g/kg of silica powder 1 or silica powder 2 were evaluated for grain quality immediately after treatment (0 month), and after 1 and 3 months. Results revealed a significant decrease in bulk density and an increase in tapped density of wheat with prolonged exposure of 3 months to silica powders 1 and 2. The angle of repose, Carr index, and Hausner Ratio values were notably higher for silica powder-treated grains after 3 months compared to the untreated control. FT4 powder rheometer analysis indicated that silica powder-treated wheat displayed increased basic flow energy, aeration ratio, and reduced stability, Despite a decline in grain quality observed after 3 months of exposure to these powders, the overall grain quality and flowability remained acceptable. The findings suggest that silica powders 1 and 2 exhibit potential as grain protectants with minimal adverse effects on grain quality and flowability.