Public health, production and preservation of food, development of environmentally friendly (cosmeto-)textiles and plastics, synthesis processes using green technology, and improvement of water quality, among other domains, can be controlled with the help of chitosan. It has been demonstrated that this biopolymer exhibits advantageous properties, such as biocompatibility, biodegradability, antimicrobial effect, mucoadhesive properties, film-forming capacity, elicitor of plant defenses, coagulant-flocculant ability, synergistic effect and adjuvant along with other substances and materials. In part, its versatility is attributed to the presence of ionizable and reactive primary amino groups that provide strong chemical interactions with small inorganic and organic substances, macromolecules, ions, and cell membranes/walls. Hence, chitosan has been used either to create new materials or to modify the properties of conventional materials applied on an industrial scale. Considering the relevance of strategic topics around the world, this review integrates recent studies and key background information constructed by different researchers designing chitosan-based materials with potential applications in the aforementioned concerns.

Quality changes induced in fresh papaya slices after cutting were evaluated using digital image analysis of colour and fractal metrics besides structural changes. Radial slices of papaya (65% and 85% ripe) were exposed to a controlled environment to simulate extreme conditions on a salad bar. Colour variation and mechanical-structural changes depended on surface dehydration, exposure time, and ripening stage. Relationship between fractal dimension, lacunarity, and time showed evidence of patterns associated with non-homogeneous colour changes related to structural variations. Fractal metrics had potential to reflect noticeable colour changes that would be useful for monitoring shelf stability of minimally processed papaya.