Release kinetics and biological properties of active films based on cellulose nanocrystal-chitosan in combination with y-irradiation to mitigate microbial load in rice

Authors: BEGUM, T - Institut National De La Recherche Scientifique (INRS); Follett, Peter; JAISWAL, L - Institut National De La Recherche Scientifique (INRS); DE GUIBERT, D - Institut National De La Recherche Scientifique (INRS); SALMIERI, S - Institut National De La Recherche Scientifique (INRS); LACROIX, M - Institut National De La Recherche Scientifique (INRS)

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2023
Publication Date: 12/30/2023
Citation: Begum, T., Follett, P.A., Jaiswal, L., de Guibert, D., Salmieri, S., Lacroix, M. 2023. Release kinetics and biological properties of active films based on cellulose nanocrystal-chitosan in combination with y-irradiation to mitigate microbial load in rice. Food Hydrocolloids. 150. Article 109697. https://doi.org/10.1016/j.foodhyd.2023.109697.
DOI: https://doi.org/10.1016/j.foodhyd.2023.109697

Interpretive Summary: A bioactive formulation of citrus extract and several plant essential oils was incorporated into a cellulose nanocrystals reinforced chitosan-based nanocomposite packaging film and tested against several food-borne pathogens in rice. The film provided high efficacy against E. coli, Salmonella, Aspergillus and Penicillium pathogens after 2 months storage and efficacy was enhance by combination with irradiation treatment. Rice treated with different bioactive nanocomposite films had no significant change in color, odor, taste, and general appreciation compared to untreated rice. Bioactive films can extend the shelf life of durable goods such as rice and improve food safety without compromising flavor or appearance.

Technical Abstract: Nanoemulsions of two antimicrobial formulations (AF-1 and AF-2) composed of citrus extracts and a mixture of essential oils (EOs) were prepared by microfluidisation. The influence of high pressure, number of cycles, and concentration of emulsifier (Tween 8) on mean droplet size (nm), polydispersity index (PDI), Zeta potential (mV), and encapsulation efficiency (EE, %) of AF-1 and AF-2 were analyzed using a central composite design. The AF-1 and AF-2 nanoemulsions were optimized at 8 KPSI pressure (2nd cycle) and 15 KPSI (3rd cycle), respectively, using 2 % Tween 80. The optimized AF-1 and AF-2 had zeta potentials of 49 and 32.3 mV, size: 116 and 40 nm, PDI: 0.17, and 0.2, and EE: 77 and 79 %, respectively. Considering their different fabrication parameters, the effects of storage temperature (4, 25, and 40 °C), bioactivity, and turbidity were examined and compared to the coarse emulsions to determine the films’ physical stability. The microbicidal properties of the AF-1 and AF-2 nanoemulsions were significantly greater against Escherichia coli O157:H7, Salmonella Typhimurium, Aspergillus niger, Penicillium chrysogenum, and Mucor circinelloides, compared to the coarse emulsions as measured by an agar disc diffusion assay. The optimized nanoemulsions were incorporated into Cellulose nanocrystals (CNCs) reinforced Chitosan-based (CH) nanocomposite antimicrobial films and tested against E. coli O157:H7, S. Typhimurium, A. niger, P. chrysogenum, and M. circinelloides in stored rice for two months with and without the presence of Y-irradiation treatment (750 Gy). The combination of Y-irradiation and bioactive CH-based nanocomposite films caused a 3.89 to 7.3 log reduction of the bacteria and fungi tested after 8 weeks as compared to control samples without the films or irradiation. Incorporation of CNC into bioactive CH-based films caused significantly slower (32 to 39 %) release of active components over 8 weeks compared to the bioactive films without CNC. Rice treated with different bioactive nanocomposite films had no significant (P>0.05) change in color, odor, taste, and general appreciation compared to untreated rice.