Nowadays, there are various devices that can be used to measure the size of food material particles, ranging from a few tenths of micrometers up to submicron scale, but most of these devices are very expensive, and in some cases, the particle size analysis is time consuming. On this concern, methods enabling the direct observation of major microscopic phenomena involved in food processing, such as proteolysis, lipolysis or starch hydrolysis are highly desirable. The purpose of this study is the application of microgap systems for evaluating the size changes during processing of different food particles, foreseeing the cost reduction and simplicity of particle size measurement. This study also aims to demonstrate the use of microchannel (MC) technology for real-time visualization of different microscopic phenomena, and can be used as a basis for future studies. The experimental setup consists of a silicon MC plate fixed inside a module, where microscopic phenomena can be observed using an optical microscope connected to a CCD camera and video recording system. The shallow region just outside the channels is called “microgap”, and its major feature is the limited height of 8 μm, where a single layer of microparticles can be formed so that avoiding the overlapping of particles. This type of configuration is necessary for a better visualization of microscopic phenomena in food processing. Experiments using pre-cultured yeast cells having around 5 μm on size were performed, enabling their real-time visualization inside the microgap.