Investigation of Physical Stability of Baobab Pulp Emulsion – for Food Application

Abstract: Background and objectives Baonaise is a novel plant-based savoury sauce. Baonaise sauce base (BSB) is produced from baobab fruit pulp. Creaming and phase separation were observed in Baonasie from previous studies at the company. In this study, concentration, temperature and type of oil, speed and time of mixing were studied to investigate the factors influencing the physical stability of baobab pulp emulsions. Oil content and processing parameters were optimized, while Baonaise with improved physical stability was prototyped. Methods BSB was made by emulsifying rapeseed oil into liquid baobab base (LBB) which was prepared by soaking baobab pulp in the water bath. Once rapeseed oil was emulsified, the premix of seasonings was added to produce Baonaise. Centrifugal method was used to accelerate the phase separation to evaluate the physical stability of baobab pulp emulsion. Particle size distribution and viscosity were measured to explain the changes in the physical stability, while the morphology of oil droplets was also checked under microscope. Results When 30%-60% w/w of rapeseed oil was added to LBB by the analytical blender at 22000 rpm for 20 minutes, a comparable centrifugal stability of BSB to the commercial mayonnaise reference was achieved. Besides, incorporating 1%-3% w/w of flaxseed oil had no significant influence on the physical stability of BSB. Finally, Neutral, Sudanese, and Nordic flavours of Baonaise were produced. Conclusion Higher ratio of oil, greater agitation intensity, prolonged emulsification and addition of mustard could reduce the risk of phase separation of baobab pulp emulsions. Results from this thesis could be used to produce BSB and Baonaise of competitive physical quality to the commercial mayonnaise.