Microstructural and Defect Analysis of Food Packaging Materials Through X-Ray Microtomography

Packaging is an important part of food products, preserving their main components and attracting consumer’s interest. However, when damage or flaws are present, food stability can be compromised. Several factors related to the design (composition and function), processing, and production of food packaging materials may result in defects that, although unavoidable, must be traceable and monitored. Few protocols have been proposed to effectively identify defects, most of which destructively or invasively, preventing the in situ characterization of the internal microstructure. We herein propose a general, simple protocol to detect and quantify defects, and analyze engineered microstructures in food packaging by X-ray microtomography. The technique requirements, such as sample characteristics and preparation, equipment setup, data acquisition and processing, as well as image segmentation, are elucidated by showcasing two common food packaging materials: paper/plastic/metal multilayers (Tetra Pak®) and polyethylene. X-ray is comprehensively depicted as an easy, helpful, noninvasive, and nondestructive method to improve the quality control of food packaging materials.