Chitosan is a product of the deacetylation of chitin, which is widely found in nature. Chitosan is insoluble in water and most organic solvents, which seriously limits both its application scope and applicable fields. However, chitosan contains active functional groups that are liable to chemical reactions; thus, chitosan derivatives can be obtained through the chemical modification of chitosan. The modification of chitosan has been an important aspect of chitosan research, showing a better solubility, pH-sensitive targeting, an increased number of delivery systems, etc. This review summarizes the modification of chitosan by acylation, carboxylation, alkylation, and quaternization in order to improve the water solubility, pH sensitivity, and the targeting of chitosan derivatives. The applications of chitosan derivatives in the antibacterial, sustained slowly release, targeting, and delivery system fields are also described. Chitosan derivatives will have a large impact and show potential in biomedicine for the development of drugs in future.

https://www.mdpi.com/1422-0067/21/2/487/pdf

Chitosan Derivatives and Their Application in Biomedicine.

Antimicrobial food packaging based on sustainable Bio-based materials for reducing foodborne Pathogens: A review

Background The growing environmental concern of plastic packaging disposal has led to the innovation of biodegradable biopolymers. Consumer demand and health concern further necessitate the emergence of active and intelligent packaging system to monitor the quality of packed food. Whereas, the use of chemical dyes as an indicator in smart packaging is not suitable for food packaging because of their high toxicity and harmful effects on human health and the environment. Hence, the researchers are focused on natural pigments derived from plants and food waste as indicating substance in biodegradable packaging and also for the valorization of food waste. Scope and approach This paper summarizes the research on the utilization of naturally derived food- and food waste-based pigments (anthocyanins, curcumin, betalains, carotenoids, chlorophyll, brazilin, quercetin, etc.) with biopolymeric matrices (starch, cellulose, chitin, gums, agar, etc.) to fabricate “smart biodegradable films”, for effective monitoring of spoilage and quality of meat products, seafood, milk, and others. Key Findings and Conclusions The results show that the smart packaging material developed by the biopolymers with plant-based pigment has the potential to replace the traditional plastic packaging materials. The extracted from food and food waste act as an indicator in smart packaging and promotes the valorization of food waste. The biodegradable packaging is economical, safe, non-toxic, sensitive, and natural pigments act as a quality indicator in packaging systems. Further, these packaging films can be optimized and commercialized and to be employed as active and intelligent packaging for visual quality evaluation of fresh food products.

Active and intelligent biodegradable packaging films using food and food waste-derived bioactive compounds: A review

Recent advances on chitosan-based films for sustainable food packaging applications

Background The recent rise in awareness of safe food and changing consumer attitudes have brought many innovations in packaging technology. Consumers are increasingly demanding natural food colorants such as carotenoids, betaines, anthocyanins and chlorophylls rather than synthetic dyes for food applications. As a result, smart packaging based on natural colorants and biopolymers has been introduced as the latest technology in the food packaging field. Smart products not only protect food from environmental hazards, but also send real-time signals (colorimetric, chemical, or electrical) to consumers for changes in the packaging environment and food quality. Scope and approach This paper reviewed the pH-sensitive smart packaging films based on natural food colorants and biopolymers and key applications in the food industry. Technological aspects associated with the natural colorant-based pH-responsive packaging films, biopolymer-based smart packaging, and the importance of natural colorants compared with synthetic dyes are discussed. The most commonly used colorimetric indicators indicating changes in pH, the application of smart food packaging films in real food systems, and the trend of future research were investigated. Key findings and conclusions Based on natural food colorants, smart packaging monitors the qualitative properties of foods in real-time, including freshness, microbial growth, and chemical changes in the product, through visual changes and quantification of pH changes in the food. It provides a fast and reliable inline assessment of food quality and safety. Nevertheless, future studies should consider commercially sustainable key points such as consumer acceptance and trust, cost, regulatory considerations (i.e. labeling) and multifunctional performance of smart films.

pH-sensitive (halochromic) smart packaging films based on natural food colorants for the monitoring of food quality and safety

Impact of acid type for chitosan dissolution on the characteristics and biodegradability of cornstarch/chitosan based films

Biodegradable chitosan films were produced using lactic and acetic acid solutions and glutaraldehyde as crosslinking agent by casting technique. The aim of this study was to evaluate the influence of different acids and the crosslinking on the characteristics and biodegradability of chitosan films. The films were analyzed through thickness, swelling degree, mechanical and thermal properties, chemical structure and biodegradability. The glutaraldehyde release was also evaluated. All films’ properties are deeply affected by the acid type and glutaraldehyde crosslinking. Crosslinking reduced the swelling degree of films, also increasing their fragility. The glutaraldehyde release from the films to the simulant solutions was not observed after the incubation period. Through biodegradation tests, it was observed that the crosslinking does not prevent films’ degradability but longer time is required. The qualitative analysis of ecotoxicity of the films suggests the possibility of composting the developed films. The films presented potential for application as membranes and in packaging, and different formulations can be used according to the desired final characteristics.

Impact of acid type and glutaraldehyde crosslinking in the physicochemical and mechanical properties and biodegradability of chitosan films

Starch and chitosan are biodegradable polymers from renewable sources that can be used to overcome the serious environmental problem caused by improper disposal of synthetic plastic materials, non-biodegradable, derived from petroleum sources. The starch–chitosan based films manufactured allow improving the better characteristics of each one, adding their good characteristics and compensating for some limitations. In this work, it was studied: two sources of starch (corn and cassava), two different modes of chitosan addition (chitosan blended in the starch filmogenic solution and chitosan as coating), and the effect of glutaraldehyde as crosslinking agent. All films were prepared by casting using glycerol as a plasticizer and were characterized by their physicochemical (water vapor permeability, water contact angle, and FTIR), mechanical, and antimicrobial properties. The properties analyzed were influenced by all variables tested. Moreover, the principal component analysis was also conducted in order to relate and describe the variables analyzed. The antimicrobial activity of the corn starch-based films containing chitosan was confirmed, and these films have potential for development of active packaging.

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Effect of chitosan addition on the properties of films prepared with corn and cassava starches

Influence of turmeric incorporation on physicochemical, antimicrobial and mechanical properties of the cornstarch and chitosan films.

Influence of Blueberry and Jaboticaba Agroindustrial Residue Particle Size on Color Change of Corn Starch Based Films Submitted to Different pH Values Solutions

Julia Menegotto Frick Pavoni

Papers

Impact of acid type for chitosan dissolution on the characteristics and biodegradability of cornstarch/chitosan based films

Impact of acid type and glutaraldehyde crosslinking in the physicochemical and mechanical properties and biodegradability of chitosan films

Effect of chitosan addition on the properties of films prepared with corn and cassava starches

Influence of turmeric incorporation on physicochemical, antimicrobial and mechanical properties of the cornstarch and chitosan films.

Influence of Blueberry and Jaboticaba Agroindustrial Residue Particle Size on Color Change of Corn Starch Based Films Submitted to Different pH Values Solutions