Chitosan Films Functionalized with Different Hydroxycinnamic Acids: Preparation, Characterization and Application for Pork Preservation

Abstract

Hydroxycinnamic acids are one category of bioactive phenolic acids that are widely distributed in plants. In this study, chitosan (CS) was functionalized with three kinds of hydroxycinnamic acids (p-coumaric acid, caffeic acid and ferulic acid) through the carbodiimide-mediated grafting method. The obtained hydroxycinnamic-acid-grafted CSs (hydroxycinnamic acid-g-CSs) were further fabricated into food packaging films through solvent casting. For the first time, the functionalities of the different hydroxycinnamic acid-g-CS films were compared. Results showed the grafting ratio of p-coumaric acid-g-CS, caffeic acid-g-CS and ferulic acid-g-CS was 73.68, 129.42 and 91.75 mg/g, respectively. Instrumental analyses confirmed hydroxycinnamic acids conjugated with CS through amide and ester bonds. The functionalization of CS film with hydroxycinnamic acids produced a more compact microstructure and higher UV light barrier ability, mechanical strength, water vapor barrier ability, thermal stability and antioxidant and antimicrobial activities. Among the different hydroxycinnamic acid-g-CS films, caffeic acid-g-CS film presented the strongest barrier, mechanical, antioxidant and antimicrobial properties. Moreover, caffeic acid-g-CS film packaging effectively extended the shelf life of pork to 10 days at 4 °C. Our results suggest caffeic acid-g-CS film can be used in the active food packaging field.

The Physicochemical, Antioxidant, and Color Properties of Thin Films Based on Chitosan Modified by Different Phenolic Acids

“…The thermal stability was not remarkably affected by the kind of added phenolic acid. A similar conclusion had been made in the study of Yong et al [25].…”

“…Zarandona et al reported that gallic acid addition improved the mechanical properties of materials based on chitosan through physical interactions, such as hydrogen bonds and electrostatic and hydrophobic forces [24]. Additionally, the chitosan films grafted by ferulic acid and caffeic acid showed better mechanical properties than pure chitosan [25]. This provides evidence that phenolic acids, acting as cross-linker, improve chitosan-based films' mechanical properties.…”

Phenolic-Rich Plant Extracts With Antimicrobial Activity: An Alternative to Food Preservatives and Biocides?

“…Interestingly, some polysaccharides, such as chitosan, have an intrinsic antimicrobial activity, which can act synergistically with antimicrobial plant phenolics. Yong et al (2021) recently grafted cinnamic acids with chitosan and observed that films elaborated with caffeic acid-chitosan conjugates had the highest antimicrobial activity. Many other authors recently investigated the effect of the addition of polyphenols to polysaccharides for food packaging applications, as recently reviewed by Zhu (2021) .…”

Antimicrobial Food Packaging with Biodegradable Polymers and Bacteriocins

“…Recent studies on composite films with the addition of apricot kernel oil used to extend the shelf life of bread indicate the possibility of complete fungus growth inhibition [ 53 ]. What’s more, chitosan films have been modified with peanut peel extract, showed better lipid antioxidation for chicken meat and pork [ 54 , 55 ]. Most of these improved chitosan films possessed better mechanical strength and water vapor barrier ability than the pristine chitosan.…”