Modifying the microstructure of low-fat yoghurt by microfluidisation of milk at different pressures to enhance rheological and sensory properties

• Published in: Food chemistry Vol. 130; no. 3; pp. 510 - 519
• Main Authors: Ciron, Chr. Ian E., Gee, Vivian L., Kelly, Alan L., Auty, Mark A.E.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-02-2012; Elsevier
• Subjects: Biological and medical sciences; Confocal laser scanning microscopy; fat globules; Food industries; Fundamental and applied biological sciences. Psychology; gel strength; gels; heat treatment; Low-fat; Microfluidisation; Microstructure; milk; Milk and cheese industries. Ice creams; particle size; Principal component analysis; Rheology; Sensory properties; Texture; viscosity; Yoghurt; yogurt; Yoghurt; Rheology; Low-fat; Microfluidisation; Sensory properties; Microstructure; Texture; Confocal laser scanning microscopy; Principal component analysis; Dairy product; Confocal microscopy; Yogurt; Pressure; Low fat product; Laser; Milk; Rheological properties
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2011.07.056

► Microfluidisation of milk (MM) modified the microstructure of low-fat yoghurts (LFY). ► Modification in microstructure improved the rheological and sensory properties. ► Higher pressures increased the effectiveness of MM in enhancing texture. ► Sensory profiles were dependent on gel particle size, microstructure and rheology. ► MM at ⩾50MPa yielded LFY with similar creaminess and texture to full-fat yoghurt.
The effects of microfluidisation of milk at different pressures, prior to heat treatment, on structural and sensory properties of low-fat stirred yoghurt, were investigated. Low-fat yoghurts prepared from microfluidised milk were compared with low-fat (1.5%) and full-fat (3.5%) control yoghurts made with homogenised (20/5MPa) milk. The microstructure of low-fat yoghurts prepared with microfluidised milk consisted of smaller and more uniform fat globules, well incorporated into more interconnected fat-protein gel networks, compared with those of control yoghurts. This modification in microstructure caused significant changes in gel particle size, sensory profile and rheological behaviour. Microfluidisation increased the gel particle size, gel strength and viscosity; marked beneficial effects were found at higher pressures (50–150MPa). Microfluidising milk at 50–150MPa increased the gel strength by 171–195% and viscosity by 98–103%, creating low-fat yoghurts with creaminess and desirable texture properties similar to, or better than, full-fat conventional yoghurt.