Nanocellulose/Nisin Hydrogel Microparticles as Sustained Antimicrobial Coatings for Paper Packaging

Abstract

Hydrogels composed of biomaterials are promising drug delivery systems. In this study, we prepared an antibacterial hydrogel by incorporating the antimicrobial peptide nisin into bagasse cellulose nanofibrils, followed by mechanic shearing to obtain hydrogel microparticles as antimicrobial coatings for paper packaging. The concept of combining nisin with a hydrogel network helps to reduce the nisin depletion disadvantage in a nisin alone coating while achieving a prolonged antibacterial efficacy in application. First, antimicrobial hydrogels were constructed by electrostatic attraction between TEMPO-oxidized cellulose nanofibrils (TOCNF) and nisin. The rheological analysis confirmed that the hydrogel with a TOCNF/nisin ratio of 3:1 formed a good gel network accompanied by a high nisin loading efficiency. The obtained hydrogel exhibited controlled release of nisin in response to pH, with a slower rate at pH 7 than that of pH 5 and pH 9. Then, the obtained hydrogel has been processed to microparticles to facilitate its application as coating on paper packaging. Highly stable TOCNFs/nisin hydrogel microparticles were obtained under a water/hydrogel ratio of 4:1 and a mechanical shearing rate of 8000 rpm. The paper with hydrogel microparticles coating displayed an enhanced tensile strength by 14.67% compared to uncoated paper. As a packaging for cheese in storage at 4 °C for 7 days, the hydrogel microparticle coating paper can significantly reduce the growth of Listeria monocytogenes on the surface of cheese and show a sustained inhibition advantage over a nisin alone coating. The utilization of hydrogel microparticles as the coating slurry provides a versatile approach for paper treatment and endows the paper with a sustained release characteristic in actively preventing the bacterial proliferation on food surfaces during storage. The finding from this work is expected to broaden the application of nanocellulose and nisin into the field of food active packaging.

Peptide hydrogels: Synthesis, properties, and applications in food science

“…(a) Development of a food packaging antibacterial hydrogel based on gelatin, chitosan, and 3‐phenyllactic acid for the shelf‐life extension of chilled chicken (Y. N. Liu et al., 2022). (b) Schematic illustration of forming the TOCNF/nisin hydrogel (P. Lu et al., 2022). (c) Scheme illustration of hydrogel microparticles preparation and application as coatings on paper (P. Lu et al., 2022).…”

“…(b) Schematic illustration of forming the TOCNF/nisin hydrogel (P. Lu et al., 2022). (c) Scheme illustration of hydrogel microparticles preparation and application as coatings on paper (P. Lu et al., 2022). (d) Zone of inhibition test of paper with different coating weight against L. monocytogenes (P. Lu et al., 2022).…”

Recent Advances in Sustainable Antimicrobial Food Packaging: Insights into Release Mechanisms, Design Strategies, and Applications in the Food Industry

“…Antimicrobial tests in vitro revealed that the film effectively inhibited the growth of E. coli, L. innocua, and A. f umigatus within 24 h. The release amount and antimicrobial activity of the film increased with increasing enzyme concentration, RH, and exposure time. In addition, Lu et al 37 blended nisin with TEMPO-oxidized bagasse cellulose nanofiber colloidal suspensions to form an antimicrobial hydrogel with a rich network structure through electrostatic interaction. The hydrogel was then processed into particles using a mechanical shear treatment and coated on packaging paper as a slow-release antimicrobial coating (Figure S8a).…”

“…Ideally, the activation and release of antimicrobial ingredients should occur when the packaging is in contact with food rather than being released in large quantities during the fabrication, assembly, or transportation of the packaging itself. Various triggering mechanisms have been employed, such as changes in temperature, humidity/moisture, − light, − pH, − and enzyme, which induce relaxations or other subtle changes in the packaging matrix without compromising its integrity and mechanical properties. These changes stimulate the movement and migration of antimicrobial active ingredients toward external media (i.e., air or food).…”

Biodegradable Nanofibrillated Cellulose/Poly-(butylene adipate-co-terephthalate) Composite Film with Enhanced Barrier Properties for Food Packaging

“…), man-made biodegradable polymers (Poly-(butylene adipate-co-terephthalate), poly (lactic acid), Polypropylene carbonate, Polyhydroxyalkanoates, Polybutylene succinate, etc.) are the focus of researchers in recent years, which will be conducive to the overall development of the economy and society, and the harmonious coexistence of human and nature [ 3 , 4 , 5 ].…”