Innovative Food Science & Emerging Technologies ( IF 6.6 ) Pub Date : 2019-09-12 , DOI: 10.1016/j.ifset.2019.102231 Saifullah Jabarkhyl , Mostafa Barigou , Shiping Zhu , Pip Rayment , David M. Lloyd , Damiano Rossetti
Whilst 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 in turbulent flow, a higher G/L ratio results in a higher gas fraction and a smaller bubble size.
Industrial relevance
Aeration 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 multi rotor-stator devices operating in turbulent flow and under atmospheric pressure achieves optimum aeration efficiency and prevents foam expansion. The use of an effective surfactant such as PGE 55 and a thickener such as Xanthan gum help provide the desired fine texture and stability for longer shelf-life. Operating at high gas-liquid ratios in turbulent flow achieves the production of finer more uniform foams with less energy input.
中文翻译:
在连续的多转子-定子装置中由非牛顿剪切稀稀液体产生的泡沫
尽管在食品工业中普遍存在充气,但是对由粘性非牛顿液体产生的泡沫所做的工作很少。我们使用具有十二个转子-定子对的连续中试规模装置,研究了由包含非离子食品级表面活性剂(PGE 55),黄原胶和白砂糖的粘性剪切稀稀液体生产泡沫的方法。阐明了工艺参数(转子速度,气液体积流量比(G / L))和液体成分(表面活性剂浓度,黄原胶浓度)对泡沫气体体积分数和气泡尺寸分布的影响。X射线计算机断层扫描是用来表征泡沫的3D微观结构。转子速度和G / L比是确定气体体积分数和气泡尺寸分布的主要因素。产生的泡沫表现出丰富的细腻质地和高的静态稳定性。对于湍流中给定的能量输入,较高的G / L比会导致较高的气体分数和较小的气泡尺寸。
行业相关性
充气在食品工业中无处不在,需要创新的方法来从粘性非牛顿介质中产生质地稳定的稳定泡沫,以满足对更高质量,更健康和更便宜产品的不断增长的需求。使用在湍流和大气压下运行的连续多转子-定子装置可实现最佳的曝气效率并防止泡沫膨胀。使用有效的表面活性剂(例如PGE 55)和增稠剂(例如黄原胶)有助于提供所需的优良质地和稳定性,以延长保质期。在湍流中以较高的气液比运行时,可以产生较少能量输入的更精细,更均匀的泡沫。