Foams generated from viscous non-Newtonian shear-thinning liquids in a continuous multi rotor-stator device

Publication date: Available online 12 September 2019Source: Innovative Food Science & Emerging TechnologiesAuthor(s): Saifullah Jabarkhyl, Mostafa Barigou, Shiping Zhu, Pip Rayment, David M. Lloyd, Damiano RossettiAbstractWhilst aeration is ubiquitous in the food industry, little work has been done on foams generated from viscous non-Newtonian liquids. We study the production of foams from viscous shear-thinning liquids containing a non-ionic food grade surfactant (PGE 55), Xanthan gum and caster sugar, using a continuous pilot-scale device having twelve rotor-stator pairs. The effects of process parameters (rotor speed, gas-liquid volumetric flowrate ratio (G/L)) and liquid composition (surfactant concentration, Xanthan gum concentration) on foam gas volume fraction and bubble size distribution are elucidated. X-ray micro-Computed Tomography is employed to characterise the 3D microstructure of the foams. Rotor speed and G/L ratio are the dominant factors in determining the gas volume fraction and bubble size distribution. The foams produced exhibit a rich fine texture with high static stability. For a given energy input, a higher G/L ratio results in a higher gas fraction and a smaller bubble size.Industrial relevanceAeration is ubiquitous in the food industry and innovative ways to generate stable foams with fine texture from viscous non-Newtonian media are needed to satisfy the increasing demand for better quality, healthier and cheaper products. The use of continuous mult...
Source: Innovative Food Science and Emerging Technologies - Category: Food Science Source Type: research