Nowadays, food materials can be well characterized at their molecular level (food chemistry) and macroscopic level (texture and rheology) thanks to the advances in these areas in the last decades. However, there is a gap in the understanding of how food materials organize at microscopic level. This research shows how the use of advanced optical super-resolution microscopy techniques like stimulated emission depletion (STED) microscopy and structured illumination microscopy (SIM) can be used to gain more information about food microstructure compared to conventional confocal microscopy. The aggregation of egg-white proteins, as well as the aggregation of casein micelles have been imaged with these techniques. The results prove that visual characterization at resolutions of few tens to hundreds of nanometers and quantitative image analysis are needed in order to gain more understanding of the complex microstructures of foods. The visualization and quantification of structures of these sizes allowed us to correlate the microscopical aggregation process with the macroscopical aggregation process seen in the rheological analysis. Moreover, the acquired images are processed with advanced image processing and image analysis software that allows the quantification of food microstructural parameters. Artificial intelligence algorithms are used to identify the structures of interest in the microscopic images and facilitates their following quantification. These has also been applied to brightfield microscopy images of egg-white foams and aquafaba foams. Finding how the measurements like size and shape of the air bubbles affect the texture of the final foam. These results show how the transition from qualitative descriptions of food microscopical images to quantitate microstructural data of food materials is needed in order to correlate microscopic understanding with macroscopic understanding. The combination of advanced microscopy and quantitative image analysis with rheology is helping us understand the fundamental phenomena occurring at the physicochemical interface of food matrices that give rise to food structure and texture.
This session is part of the Scientific Discovery Workgroup Research Promotion (Pre-Tenured Faculty)