Chitooligosaccharides and their biological activities: A comprehensive review.

Chitosan: Structural modification, biological activity and application.

Enzymatic modification of polysaccharides: Mechanisms, properties, and potential applications: A review.

Structural properties of films and rheology of film-forming solutions of chitosan gallate for food packaging.

Chitosan (aminopolysaccharide) exhibiting excellent functional properties was found to be a good natural source in various applications. However, practical use of chitosan was generally limited due to its weak solubility in neutral pH, its poor workability and low antioxidant activity. For a breakthrough in utilization, the functionalization of chitosan will be a key point, allowing the introduction of desired properties and enlarging the field of its potential applications. Enzymatic or chemical functionalizations of chitosan were carried out based on its reactive groups (-NH2 and -OH). Due to growing safety and environmental concerns, enzymatic methods were constantly investigated as an attractive alternative to toxic and non-specific chemical approaches. This review discusses the mechanisms of enzymatic functionalization and compares the applied systems, enzymes and materials for enzymatic functionalization of chitosan. A focus is also paid concerning the current applications of enzymatically modified chitosan derivatives in the field of biomedical, pharmaceutical, food, environmental and material applications.

Enzymatic synthesis of chitosan derivatives and their potential applications

Rheological and antioxidant power studies of enzymatically grafted chitosan with a hydrophobic alkyl side chain

Summary Chitosan is a natural polymer, which has become a quite noteworthy material because of its high chemical versatility and functional properties for developing derived compounds with improved or new properties. Among the chemical or enzymatic modifications made to the chitosan molecule are the chitooligosaccharides as well as the grafting of functional groups such as saccharides, oligosaccharides, alkyl groups, cyclodextrins, organic acid, lactide, polylactide, and polyphenol, providing chitosan derivatives with improved solubility and enhanced antimicrobial activity, chelating ability, moisturizing qualities, and healing properties, among others. These new functionalized chitosans have shown high potential for application in medicine, water treatment, pharmaceutical and cosmetic industry, agriculture, and food. This chapter addresses the scope of current functional chitosan derivatives and explains the relationship between chitosan structure and its modifications and the specific properties in the final product as well as its potential applications, particularly in the agricultural and food sectors.

New Bioactive Biomaterials Based on Chitosan

For sale in the domestic market, Hass avocados are kept in non-biodegradable plastic nets and stored at an ambient temperature. The fungus Colletotrichum gloeosporioides can cause important losses at this stage. Consequently, formulations based on polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) 60/40 biodegradable blends added with pine essential oil (PEO) at 10, 12, 14, and 20% and coated with 1% chitosan (CH) were used for the elaboration of nets, which were evaluated on C. gloeosporioides and Rhizopus stolonifer on nutrient media and fruit and on the ripening behavior of Hass avocados at ambient temperature. The spore germination stage of C. gloeosporioides was the most extensively damaged (78% inhibition). The incidence of anthracnose was notably reduced by almost 80% in the avocados stored in the 60/40 PLA/PBAT nets coated with 1% CH. The overall values regarding weight loss, °Brix, and dry matter were c.a. 23.5%, 7.5, and 24.5%, respectively. The changes in firmness, color, and CO2 production were particularly associated with the initial harvest index and storage temperature rather than with the nets. In future research, essays on nets should include evaluations at the commercial levels.

https://www.mdpi.com/2223-7747/11/17/2278/pdf?version=1662013733

Leonor Zavaleta-Avejar

Papers

Rheological and antioxidant power studies of enzymatically grafted chitosan with a hydrophobic alkyl side chain

New Bioactive Biomaterials Based on Chitosan

Anthracnose Disease Control and Postharvest Quality of Hass Avocado Stored in Biobased PLA/PBAT/Pine Essential Oil/Chitosan Active Packaging Nets