Compilation of analytical methods to characterize and determine chitosan, and main applications of the polymer in food active packaging

Antimicrobial films for food packaging applications have received increasing attention from the industry in recent years. Due to their exceptional properties, such as non-toxicity, biodegradability, antimicrobial characteristics, and biocompatibility, chitosan has proven useful for the development of active materials. This review aims to provide an overview of the main techniques used for the characterization of chitin and chitosan, including Fourier transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, UV spectrophotometry, viscosimetry, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), titrations, scanning electron microscopy SEM) and size exclusion chromatography (SEC) among others. In addition, the main applications of the polymer in food packaging are also reported.