Valorization of Native Soluble and Insoluble Oat Side Streams for Stable Suspensions and Emulsions

Among different cereals, oat is becoming more popular due to its unique composition and health benefits. The increase in oat production is associated with an increase in related side streams, comprising unutilized biomass that is rich in valuable components, such as polysaccharides, proteins, and antioxidants. To valorize such biomass, it is fundamental that side streams enter back into the food production chain, in respect of the circular economy model. Here, we propose the use of soluble and insoluble oat-production side-stream in suspensions and emulsions, avoiding any further extraction, fractionation, and/or chemical derivatization. Our approach further increases the value of these side streams. To this aim, we first studied the effect of thermal and mechanical processes on the behavior and properties of both soluble and insoluble oat side-stream fractions in water and at air/water interface. Then, we characterized the emulsifying and stabilizing abilities of these materials in oil-in-water emulsions. Interestingly, we found that the insoluble fraction was able to form stable suspensions and emulsions after mechanical treatment. The oil droplets in the emulsions were stabilized by anchoring at the surface of the insoluble particles. On the other hand, the soluble fraction formed only stable viscous solutions. Finally, we demonstrated that the two fractions can be combined to increase the storage stability of the resulting emulsion. Our results highlight that oat production side streams can be used as novel bio-based emulsifiers, showing the great potential behind the underutilized cereal-side-stream biomass.

Automated summary

Oat production side streams, rich in valuable components, can be used as novel bio-based emulsifiers to increase their value in a circular economy model. Research shows that the insoluble fraction can form stable suspensions and emulsions, while the soluble fraction forms viscous solutions.