Browsing by Subject "oat drink"

Plant-based milks can be unstable during storage due to the colloidal structure of these drinks. In general, e-coded additives are used to increase the viscosity of the drinks and hence, improve stability. Oat beta-glucan, microbially or enzymatically produced exopolysaccharides, such as dextran, and flaxseed mucilage are natural hydrocolloids that are known to have the ability to increase viscosity. These hydrocolloids could potentially be used to replace e-coded additives. The aim of this thesis was to study the stabilizing potential of oat beta-glucan, exopolysaccharides, and flaxseed mucilage in oat drinks. Oat drinks with added hydrocolloids were compared to control samples that were oat drink without added hydrocolloids and oat drinks with pectin at concentrations of 0.2% and 0.4%. Oat beta-glucan, exopolysaccharides, and flaxseed mucilage were added to the prepared drinks by replacing 10% of water with the extracts. Additionally, stabilizing properties of isolated and freeze-dried microbially produced dextran was studied by adding it to the drinks at concentrations of 1.5%, 1.0% and 0.5%. Stability of the oat drinks was assessed during a 14−day storage period by measuring the viscosity, pH, and phase separation. Results of this study demonstrated the stabilizing potential of the natural hydrocolloids. The addition of hydrocolloids increased the viscosity in all samples. The inclusion of natural hydrocolloids led to a similar stability, and in some cases also significantly lower viscosity, compared to pectin added drinks. Oat beta-glucan had a remarkable positive impact on the stability of oat drinks. This was most likely due to the network formation of oat beta-glucan molecules, which decreased the sedimentation of colloidal particles. Enzymatically produced dextran also improved the stability of oat drinks, which might be attributed to the viscosity-increasing -capacity of dextran. However, the stabilizing role of microbially produced exopolysaccharides was not shown. For future study, the molecular interactions of natural hydrocolloids in the colloidal solution should be investigated.