Observation of processed rice using synchrotron radiation X-ray phase-contrast imaging.

As a result of increasing elderly population, the number of people with dysphagia and difficulty eating is expected to increase as well. It is not always feasible to cook meals to the proper texture for elderly individuals and people with dysphagia living at home. Accordingly, there is high market demand for ready-made texture-modified foods for home consumption. Many methods have been widely used to analyze the structural properties of foods. However, it is difficult to observe the structure of foods in a nondestructive manner with the conventional analysis methods. To observe food as it is without destroying it, we adopted X-ray phase-contrast computed tomography (CT) using a crystal interferometer in this study. The samples were commercially available precooked rice porridge and two texture-modified rice products satisfying the Universal Design Food criteria. A texture profile analysis was also performed to compare the phase-contrast images and the food properties. In the phase-contrast images, both the ingredients and cohesion in the samples were successfully observed. It was also found that the texture-modified rice products were easier to eat and swallow than the rice porridge. These results show that X-ray phase-contrast CT using a crystal interferometer is a promising method for nondestructive observation of food structures and is expected to open up new horizons in food science.