Microstructural changes in acid milk gels due to temperature-controlled high-intensity ultrasound treatment: Quantification by analysis of super-resolution microscopy images

High-intensity ultrasound (HIU) can be applied to food materials to create novel structures and textures, and as a method of processing. HIU treatment of milk modifies the gelation behaviour, but the microstructural impact is poorly understood. Milk samples were treated with HIU at three temperatures: 27°C, 50°C, and 70°C. Acid milk gels were formed from the milk and imaged using super-resolution stimulated emission depletion and confocal microscopy. Quantitative image analysis was applied and demonstrated that HIU treatment leads to measurable changes in both protein network morphology and degree of association of the fat droplets with the protein network.