Effect of oil content on pin-milling of soybean

Milling is a critical step to prepare plant-based food ingredients by dry fractionation. It should provide a dispersible flour of finely milled particles composed of different cellular substructures. Especially, for raw materials with higher oil content such as soybean, this is challenging. We present an investigation on the effect of oil content on milling yield, particle size, energy use and flour dispersibility upon pin-milling of soybean. Soybean (20 g oil/100 g dry solids) and mechanically de-oiled soybeans (9–17 g oil/100 g dry solids) were subjected to pin-milling experiments. Increasing soybean oil content limited milling to smaller particles and lowered the overall milling yield. Particle size reduction can be described with an adapted Bond's model with oil content as an input parameter. The produced soy flours were well dispersible

Dextrose equivalence of maltodextrins determines particle morphology development during single sessile droplet drying

Particle morphology development during spray drying is critical to powder properties. The aim of this study was to investigate whether the dextrose equivalence (DE) of maltodextrins can be used as an indicator for the final particle morphology. Maltodextrins were characterized on glass transition temperature (Tg) and viscosity, where low DE-value maltodextrins exhibited higher Tg and viscosity than high DE maltodextrins (≥21). A new custom-built sessile single droplet dryer was used to analyse morphology development of minute maltodextrin droplets (R0 ~ 100 μm) at 60 °C and 90 °C. Droplets with low DE showed early skin formation (2–5 s) and developed smoothly shaped particles with large cavities. Rheology on low DE maltodextrin films at dry matter of 82% (w/w) suggested that drying droplets acquired elasticity after locking providing resistance against surface compression. After locking morphology development is probably halted as the glassy state is approached. On the contrary, rheology on high DE maltodextrin (≥21) films at dry matter of 93% (w/w) suggested that drying droplets with high DE developed viscous skins, which are susceptible to surface deformations, leading to wrinkling, folding or creasing particle morphologies. The results demonstrated that DE-value may be used as an indicator for particle morphology development when interpreted in view of the process conditions.</p