Chitosan, Zein and Essential Oil as Bio-based Coating: Comparison
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This entry is adapted from: https://www.mdpi.com/2079-6412/10/5/497

Modifications of the packaging paper surface play an important role in a variety of industries, especially in the food sector. Uncoated paper has poor water and oil barrier properties due to its porous structure. Packaging paper could be successfully coated with different coating solutions containing combinations of chitosan, zein and rosemary essential oil. The chitosan and zein were actually coated in two layers; the mixed chitosan–rosemary oil and the mixed zein–rosemary oil were each applied as one layer to the paper. The results showed increased oil barrier properties in the papers coated with mixed zein–rosemary oil and reduced water permeability in the papers coated with the chitosan–rosemary oil coating solution. The result of this two-layer coating showed excellent water and oil barrier properties. All the coated papers showed a high thermal stability, especially those coated with chitosan, zein and rosemary oil layer by layer. Scanning electron microscopy was used to verify the surface di erences of the coated papers, such as the closed structure, pores and smoother surface, especially in the layer-wise coated samples. Due to their good mechanical and chemical properties, coated papers with rosemary oil can be used in many applications, possibly also in the field of repellents.

  • dual layer
  • rosemary oil
  • absorptiveness
  • thermogravimetric analysis
  • properties

1. Introduction



Latest tendencies show that packaging materials, with which producers reduce environmental pollution, are based on bio polymers and increase their consumption due to their biodegradable, nontoxic and environmentally friendly nature, as well sufficient barrier properties. Packaging paper plays an important role in many industrial sectors. In general, packaging paper can be exposed to many external environmental influences such as humidity, temperature, stress, forces, pressure and chemical impacts. [[1],[2]]. Therefore, modifications of the paper surface play an important role in a variety of industries. Namely, unmodified paper has poor water and oil resistance due to its porous structure and the presence of hydroxyl groups [[1],[2]]. There are also lower tensile properties as well as tearing and bending strengths, which are important for packaging production. Lamination and coatings usually enhance the paper properties. In recent years, many researchers have carried out applications with bio-based coatings to achieve adequate paper properties [[3],[4],[5],[6]]. In the last decade, new technologies for food packaging have come forth, including active packaging among the most promising innovations. It consists in incorporating active compounds into the packaging material, which are useful for food protection as well as in terms of antioxidant and/or antimicrobial activity. Recently, polysaccharides have become widely used as coating solutions, including chitin, chitosan and starches. The availability on the market and great properties such as non-toxicity, gas, aroma and grease barriers make it possible to use these materials in many applications [[7]]. On the other hand, polysaccharides have low hydrophilicity and thus limited use in materials where water vapour barriers are of the utmost importance [[8],[9]].

2. Overview of vVarious bio-based cBio-Based Coatings and uUsage of eEssential oOils in pPackaging cCoatings

2.1 Chitosan and bio-based paper coatings

Chitosan, a non-toxic and widely used polysaccharide, is obtained through the deacetylation of

chitin [[8]]. Due to its properties such as high crystallinity and hydrogen bonding between molecular chains with high oxygen properties, it has aroused interest in food packaging for edible films and coatings [[9],[10],[11],[12]]. One of the advantages of chitosan is its high grease barrier properties, which are due to its positive charge at the amino group under acidic conditions, as it binds negatively charged molecules [[8]]. For its good barrier properties (antimicrobial, mechanical, against grease, oxygen) chitosan coatings can also be used as a barrier in packaging [[11],[12],[13],[14]]. In several chitosan coatings, additional biopolymers have been added to achieve hydrophobic properties of the substrate [[14],[15]].

2.2 Zein and bio-based paper coatings

Zein is a biodegradable polymer obtained from corn waste. Due to its molecular structure, zein has a good resistance to water but poor resistance to grease [[16]]. Many authors have improved zein paper coatings or packaging films with additional additives like orange peel oil, tea extract powder, Zataria multiflora Boiss., essential oil, tannic acid, etc. [[17],[18]]. Interest is growing in incorporating antioxidant and antimicrobial agents into zein coatings or films to produce functional films for food applications [[19]]. Gagon et al. presented the fabrication of polypropylene packaging material with zein to improve antimicrobial properties [[19]].

2.3. Chitosan, zein and essential oils as paper coatings

Chitosan and zein have mostly been used separately in the coating industry, but there are only few studies with a combination of the mentioned components [[20]]. On the other hand, there is a wide range of research on applications and the use of essential oils in paper coatings to obtain antimicrobial, repellent and oil-resistant materials [[19][20][21]]. Some studies have shown that essential oils should have a high potential as natural pesticides [[22]. A few examples of studies have shown that rosemary essential oil has been e ectively used in packaging materials as a natural insecticide (repellent, digestive, growth retardant) [[23]]. Abdollahi et al. studied the changes of the water vapour properties of chitosan film with incorporated rosemary essential oil [[24]]. The amount of 1.5% v/v rosemary oil was sucient to increase the hydrophobicity of chitosan–rosemary packaging film. The antioxidant and antimicrobial properties of the essential oils are attributed to the phenolic compounds, which cause the reduction of the lipid oxidation and microorganisms growth in food, [[25]]. Pires et al. successfully developed chitosan/montmorillonite bionanocomposites incorporated with rosemary essential oil [[26]]. They proved that the novel active packaging was appropriate for the packaging of the fresh poultry meat. On the other hand, some research showed potential in terms of the repellent activities of packaging films coated with rosemary oil, against the red flour beetle [[27]].

3. Coated paper and its properties

3. Coated Paper and Its Properties

The surface properties of the coated papers correspond to the changes in mechanical, water and oil resistance. The absorption, thickness, moisture and roughness of uncoated paper have a great influence on the properties of the coatings. A good fibre coverage translates into the coated paper’s smoothness. If the coating weight distribution is uneven, many properties can deteriorate after coating, which can a ect the printing process (uneven print image and mottling).

The double coating with rosemary essential oil could also be a good example as a repellent active packaging material. Zein, however, is water-repellent but laces oil resistance and on the other hand there is chitosan with opposite properties. To guarantee a good runnability of paper web through the whole papermaking process, di erent strength properties were needed. Because base paper is wetted in the coating procedure, a good strength is required. The fibres and the fibre layers are connected by fibre bonds, which transmit shear forces and other network loads. The amount and size of the fibre bonds depends on the internal fibrillation, which also influences fibre swelling, elongation and flexibility. The tensile-elongation behaviour depends on the moisture content of the paper. Namely, tensile strength increases, but the tear and elongation are reduced when the paper is dried. Polysaccharides blend with other polymers, in varying proportions, and also improve the tensile properties. Tensile strength and elongation at break are very important in packaging materials due to the transport and handling of the products (Figure 1).

 

Coatings 10 00497 g006 550

 

 

SEM micrographs of the uncoated (a), chitosan and zein coated (b), blend zein and rosemary oil coated (c), blend chitosan and rosemary oil coated (d), chitosan and blend zein and rosemary oil coated (e), pure chitosan in one layer coated (f) and the pure zein in one layer coated (g) paper, at magnification 500

 

Figure 1. SEM micrographs of the uncoated (a), chitosan and zein coated (b), blend zein and rosemary oil coated (c), blend chitosan and rosemary oil coated (d), chitosan and blend zein and rosemary oil coated (e), pure chitosan in one layer coated (f) and the pure zein in one layer coated (g) paper, at magnification 500×.

References

  1. Farhat, W.; Venditti, R.A.; Hubbe, M.; Taha, M.; Becquart, F.; Ayoub, A.; A review of water-resistant hemicellulose-based materials: Processing and applications.. ChemSusChem 2017, 10, 305–323, https://doi.org/10.1002/cssc.201601047.
  2. Shankar, S.; Rhim, J.W.; E ects of poly (butylene adipate-co-terephthalate) coating on the water resistant, mechanical, and antibacterial properties of Kraft paper.. Prog. Org. Coat 2018, 123, 53–159.
  3. Gicquel, E.; Martin, C.; Yanez, J.G.; Bras, J.; Cellulose nanocrystals as new bio-based coating layer for improving fiber-based mechanical and barrier properties.. J. Mater. Sci. 2017, 52, 3048–3061.
  4. Ma, S.; Li, T.; Liu, X.; Zhu, J.; Research progress on bio-based thermosetting resins.. Polym. Internat. 2016, 65, 164–173..
  5. Helanto, K.E.; Matikainen, L.; Talja, R.; Rojas, O.J.; Bio-based polymers for sustainable packaging and biobarriers: A critical review.. BioResources 2019, 14, 4902–4951..
  6. Koppolu, R.; Lahti, J.; Abitbol, T.; Swerin, A.; Kuusipalo, J.; Toivakka, M.; Continuous processing of nanocellulose and polylactic acid into multilayer barrier coatings.. ACS Appl. Mater. Inter. 2019, 11, 11920–11927..
  7. Vrabič Brodnjak, U.; Influence of ultrasonic treatment on properties of bio-based coated paper.. Prog. Org. Coat. 2017, 103, 93–100..
  8. Bordenave, N.; Grelier, S.; Coma, V; Hydrophobization and antimicrobial activity of chitosan and paper-based packaging material.. Biomacromolecules 2010, 110, 88–96..
  9. Bordenave, N.; Grelier, S.; Pichavant, F.; Coma, V.; Water and moisture susceptibility of chitosan and paper-based materials: Structure–property relationships.. J. Agric. Food Chem. 2007, 55, 9479–9488..
  10. Xu, Y.X.; Kim, K.M.; Hanna, M.A.; Nag, D.; Chitosan–starch composite film: Preparation and characterization. Ind. Crop. Prod.. Ind. Crop. Prod. 2005, 21, 185–192.
  11. Wang, S.; Jing, Y.; E ects of a chitosan coating layer on the surface properties and barrier properties of kraft paper.. BioResources 2016, 11, 1868–1881.
  12. Ham-Pichavant, F.; Sèbe, G.; Pardon, P.; Coma, V.; Fat resistance properties of chitosan-based paper packaging for food applications.. Carbohyd. Polym. 2005, 61, 259–265.
  13. Rastogi, V.K.; Samyn, P.; Bio-based coatings for paper applications. Coatings 2015, 5, 887–930..
  14. Reis, A.B.; Yoshida, C.M.; Reis, A.P.C.; Franco, T.T; Application of chitosan emulsion as a coating on Kraft paper. Polym. Int. 2011, 60, 963–969.
  15. Mujtaba, M.; Morsi, R.E.; Kerch, G.; Elsabee, M.Z.; Kaya, M.; Labidi, J.; Khawar, K.M.; Current advancements in chitosan-based film production for food technology; A review.. Int. J. Biol. Macromol. 2019, 121, 889–904.
  16. Hamdani, S.S.; Li, Z.; Rabnawaz, M.; Kamdem, D.P.; Khan, B.A.; Chitosan-graft-polydimethylsiloxane/zein coatings for the fabrication of environmentally friendly oil-and water-resistant paper. ACS Sustain. Chem. Eng. 2020, 13, 5147–5155.
  17. Wang, Y.; Zhang, R.; Ahmed, S.; Qin,W.; Liu, Y.; Preparation and characterization of corn starch bio-active edible packaging films based on zein incorporated with orange-peel oil.. Antioxidants 2019, 18, 191.
  18. Kashiri, M.; Cerisuelo, J.P.; Domínguez, I.; López-Carballo, G.; Muriel-Gallet, V.; Gavara, R.; Hernández-Muñoz, P.; Zein films and coatings as carriers and release systems of Zataria multiflora Boiss. essential oil for antimicrobial food packaging.. Food Hydrocolloid. 2017, 70, 260–268.
  19. Gagon, A.T.; Britt, D.W.; Bastarrachea, L.J.; Zein-modified antimicrobial polypropylene: Characterization and reusability upon UV-A light exposure.. LWT 2020, 121, 108983.
  20. Zhang, L.; Liu, Z.; Wang, X.; Dong, S.; Sun, Y.; Zhao, Z.; The properties of chitosan/zein blend film and e ect of film on quality of mushroom (Agaricus bisporus).. Postharvest Biol. Tec. 2019, 155, 47–56.
  21. Mousavi Kalajahi, S. E., Alizadeh, A., Hamishehkar, H., Almasi, H., & Asefi, N.; Orange juice processing waste as a biopolymer base for biodegradable film formation reinforced with cellulose nanofiber and activated with nettle essential oil. . Journal of Polymers and the Environment, 2022, 30, 258-269..
  22. Kashiri, M.; Cerisuelo, J.P.; Domínguez, I.; López-Carballo, G.; Muriel-Gallet, V.; Gavara, R.; Hernández-Muñoz, P.; Zein films and coatings as carriers and release systems of Zataria multiflora Boiss. essential oil for antimicrobial food packaging.. Food Hydrocolloid 2017, 70, 260-268.
  23. Shektaei, Z. A., Pourehsan, M. M., Bagheri, V., Ghasempour, Z., Mahmoudzadeh, M., & Ehsani, A.; Physico-chemical and antimicrobial characteristics of novel biodegradable films based on gellan and carboxymethyl cellulose containing rosemary essential oil.. International Journal of Biological Macromolecules 2022, 12, 163, https://doi.org/10.1016/j.ijbiomac.2022.12.163.
  24. Abdollahi, M.; Rezaei, M.; Farzi, G.; A novel active bionanocomposite film incorporating rosemary essential oil and nanoclay into chitosan.. J. Food Eng. 2012, 111, 343–350.
  25. Shahrampour, D., & Razavi, S. M.; Fabrication and characterization of novel biodegradable active films based on Eremurus luteus root gum incorporated with nanoemulsions of rosemary essential oil. . Progress in Organic Coatings, 2023, 175, 107360.
  26. Pires, J.R.A.; de Souza, V.G.L.; Fernando, A.L.; Chitosan/montmorillonite bionanocomposites incorporated with rosemary and ginger essential oil as packaging for fresh poultry meat. Food Packag. Shelf Life. 2018, 17, 142–149.
  27. Li, Y. X., Erhunmwunsee, F., Liu, M., Yang, K., Zheng, W., & Tian, J.; Antimicrobial mechanisms of spice essential oils and application in food industry.. Antimicrobial mechanisms of spice essential oils and application in food industry. 2022, 1, 132312.
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