Skip to main content
NCBI home page
Iranian Journal of Veterinary Research logoLink to Iranian Journal of Veterinary Research
. 2022;23(1):53–60. doi: 10.22099/IJVR.2021.38534.5609

Evaluation of the properties and antibacterial activity of microchitosan film impregnated with Shirazi thyme (Zataria multiflora) and garlic (Allium sativum) essential oils

Z Ebadi 1, H Ghaisari 2, B Tajeddin 3, S S Shekarforoush 2,*
PMCID: PMC9238934  PMID: 35782351

Abstract

Background:

Recent research has shown that chitosan has good moisture-absorbing properties at the micro and nanoscale, and seems to be a good candidate for the production of biodegradable moisture-absorbing films.

Aims:

The aim of this study was to evaluate the properties and antibacterial activity of starch-based microchitosan (MCH) films impregnated with two essential oils (EOs).

Methods:

MCH films with varying thicknesses were made from cornstarch (6%), microchitosan (1%), glycerol (2.25%), and/or EOs (2%), and their characteristics, including swelling degree (SD), tensile strength (TS), and elongation at break (EB%), were examined. The film structures were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). To determine the antibacterial activity against Escherichia coli and Staphylococcus aureus, two EOs of Shirazi thyme, garlic, and a mixture of them were used in the experimentation.

Results:

The EB% and TS had a linear relationship with the thickness of samples and improved by increasing the thickness of films. The XRD pattern showed that the MCH films had an amorphous structure. SEM of the films showed a homogeneous dispersion of MCH in the starch matrix without any porosity. The AFM images showed a simultaneous increase in the thickness of the MCH films and surface roughness. The film was able to absorb water up to 15.78 times its weight in 48 h. The inhibition zone of films containing 2% thyme EO was 42.0 mm for S. aureus and 12.3 mm for E. coli (P<0.05).

Conclusion:

MCH film containing Shirazi thyme can be described as a moisture-absorbing antibacterial pad and is a new idea for active food packaging to increase the shelf life of foods with fully degradable properties.

Key Words: Anti-bacterial, Food packaging, Microchitosan, Moisture absorbent pad, Starch matrix film

Introduction

The most common food packaging materials are plastics (about 50%) (FICCI, 2016 ▶; Jeevahan and Chandrasekaran, 2019 ▶), and due to many economic and practical aspects such as low cost, light weight, and convenience, it is estimated that their use will increase in the future. Biopolymers and films have been considered by researchers as a desirable option that has a great capacity for artificial replacement. However, the film properties are not the same as traditional packaging materials, such as synthetic plastics (Turalija et al., 2016 ▶; Bhardwaj et al., 2019 ▶).

One of the main biopolymers is polysaccharides. They have many properties that make them attractive for use in the food industry, including hydrophilicity, biodegradability, biocompatibility, low toxicity, bioactivity, antimicrobial activity, thickening, and film formation (Mohamad and Fahmy, 2012 ▶; Chanphai and Tajmir-Riahi, 2018 ▶; Ribeiro et al., 2018 ▶). Considerable investigation has been recently directed to the use of naturally abundant polymers such as chitin, cellulose, and chitosan to produce films (Amjadi et al., 2019 ▶; Noorbakhsh-Soltani et al., 2019 ▶; Yang et al., 2020 ▶). Chitin and chitosan are natural amino polysaccharides that are produced in about the same amount as cellulose (Kumar, 2000 ▶). They have an exceptional performance in making bio-composites. Chitosan is a green compound generally applied in different fields, including food, agriculture, biomedicine, cosmetics, and other industries. Several reports including different attributes of the chitosan functions have been published in recent years (Kumar, 2000 ▶; Amidi et al., 2010 ▶; Mohamad and Fahmy, 2012 ▶; Chanphai and Tajmir-Riahi, 2018 ▶; Silva et al., 2018 ▶; Qin et al., 2019 ▶; Sun et al., 2019 ▶).

Chitosan is a cationic biopolymer that makes it appropriate for binding to negative-charged materials (Wei et al., 2009 ▶; Ribeiro et al., 2018 ▶). The chemical properties of chitosan are defined by the molecular weight, degree of deacetylation, and viscosity (van der Lubben et al., 2001 ▶). The molecular weight of the chitosan can be low, medium, or high (70, 190-310, or 500 kDa, respectively) (Schiffman and Schauer, 2007 ▶).

The main cause of food spoilage is moisture in foods and food respiration, which affects the quality and shelf life of food products. Recently, the effective method of monitoring and binding excess water accumulations in active packaging systems, has found much interest, and moisture scavengers such as sachets, pads, or sheets have been introduced. Many moisture absorbers in markets consist of silica gel, natural clays, calcium chloride, and polymeric materials (Ozdemir and Floros, 2004 ▶; Bhardwaj et al., 2019 ▶). A few articles have discussed replacing natural moisture-absorbing films with synthetic ones. Natural moisture-absorbing films can be used because of their ability to overcome the problems associated with water condensation in food packaging.

Besides, many reports have shown that chitosan at micro and nano scales has moisture-absorbing and antibacterial properties (Radusin et al., 2016; Turalija et al., 2016 ▶; Qin et al., 2019 ▶), and the essential oils (EOs) may enhance the antimicrobial activity of films. Therefore, in this study, microchitosan (MCH) film impregnated with two EOs as a degradable moisture-absorbing antibacterial pad was prepared, and its mechanical and antibacterial properties were evaluated.

Materials and Methods

Materials

MCH (deacetylation, 85%) with the molecular weight of 50-80 KDa and mesh size 60 µm were produced in Nano Novin Polymer Co. (Sari, Mazandaran, Iran). Calcium chloride anhydrous was provided by Duksan Co., Korea. Magnesium nitrate and glycerol were purchased from Fluka Co. and Merck Co., Germany, respectively. EOs of Shirazi thyme (Zataria multiflora) and garlic (Allium sativum) were purchased from Barij Essence and Herbal Exir Companies (Iran). Escherichia coli (ATCC 35218) and Staphylococcus aureus (ATCC 6538) were provided by the Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Iran. Corn starch containing approx. 73% amylopectin and 27% amylose was purchased from Sigma-Aldrich (S4126, EC: 232-679-6), USA.

Methods

Film preparation

The films were prepared according to Chaichi et al. (2017) ▶ method, with some modifications. Three grams of corn starch were dissolved in 50 ml of aqueous solution of acetic acid (1% v/v) and stirred using a stirrer heater at room temperature for 30 min at 1000 ×g (Heidolf, Standard Hei, Germany). In parallel, 1.00 g of MCH was dispersed in 40 ml of aqueous solution of acetic acid (1% v/v) and stirred at room temperature for 30 min at 1000 ×g. After complete dissolution, 2.25 g of glycerol was added. The solutions were then mixed, the volume adjusted to 100 ml with acetic acid (1% v/v), and stirred again at 90°C at 1000 ×g for 30 min. The homogenized solutions were poured into Petri dishes and permitted to dry at room temperature (3-4 days). The dried films were removed from the plates and placed in a desiccator containing a saturated magnesium nitrate solution at 25°C and 52.8% relative humidity (RH) for at least 48 h. The different thicknesses of films were attained using different amounts of (g) intended solutions in the Petri dishes.

To produce antibacterial films, 2% of Shirazi thyme and garlic EOs and a mixture of them (1% of each) and tween 80 (0.1% V/V for each percentage of EOs) were added to the final solution and homogenized using a high-shear mixing homogenizer (Heidolph-DIAX900, Germany) at 14000 ×g for 3 min. The other stages of production were the same as before.

Film characterization

Thickness

The thickness of films was measured using a digital micrometer (Mitutoyo Co., Japan), with an accuracy of 0.001 mm. Five points were randomly selected in each sample and their thickness was measured. Their mean was reported as the sample thickness.

Swelling degree (SD)

Film samples were cut into 2 × 2 cm2 pieces; after weighting (wi), they were immersed in distilled water, and the swelling capacities were measured at intervals of 1, 24, and 48 h. The SD of the films was calculated by the following equation (Lavorgna et al., 2010 ▶):

SD=Wf-WiWi

Where,

Wf: The final weights (in g) of the samples

Wi: The initial weights (in g) of the samples

Mechanical properties

The mechanical properties of the films were measured using a texture analyzer (Hounsfield, Model H5KS, UK) with a 500 N load cell, according to ASTM standard method D882 (ASTM, 2007). Prior to the test, the films were cut into rectangular strips with a dimension of 4 × 1 cm2. The initial grip spacing and crosshead speed were set at 40 mm and 10 mm per min, respectively. Tensile strength (TS) and the presence of elongation at break (EB%) were calculated by the following equations:

TS MPa=Maximum Force(Film thickness)×(Film width)

EB%=Final length-initial lenghtInitial length×100

X-ray diffraction (XRD)

The film samples were analyzed for XRD properties according to Koo (2019) by an X-ray Diffractometer (Model X’Pert MPD, Panalytical, Netherlands).

Scanning electron microscopy (SEM)

A scanning electron microscope (VEGA, TESCAN, Czech Republic) was used to examine the morphology of the films. Briefly, film samples were frozen with liquid nitrogen, fractured, mounted, coated with gold (2 min) on a sputter coater (K450x-EMITECH-England), and finally observed. All SEM photomicrographs were obtained using an accelerating voltage of 10 kV and at different magnifications (1000, 5000, and ×15000).

Atomic force microscopy (AFM)

Topographical images of MCH films were performed using a multimode atomic force microscope (Dualscope/Rasterscope C26, DME, Denmark). The height (Sz), average roughness (Sa), and root mean square surface roughness (Sq) values of different scan sizes of two different film thicknesses were calculated. The equipment was operated in a non-contact mode in the air using a silicon tip (curvature radius <10 nm and a cantilever length of 230 μm) with a resonance frequency of 175 kHz.

Gas chromatography/mass spectrometry ( GC/ MS ) analysis of EOs

GC/MS analysis was carried out using an Agilent 6890 GC/MS instrument equipped with BPX5 capillary columns (30 m × 0.25 mm i.d., 0.25 µm thickness, Agilent technologies). Helium was used as the carrier gas while the flow rate was adjusted to 1 ml/min, and an injection volume of 1 µL was used. The mass spectrometer was run in the electron ionization (EI) mode at 70 eV. The injector temperature was 220°C, and the detector temperature was 290°C. The data were collected under the following conditions: an initial temperature of 60°C, a program rate of 2°C/min for the polar column (up to 220°C), and 3°C/min for the non-polar column (up to 240°C). The ingredients of EOs were identified by comparison of their relative retention times and mass spectra with Willey7n, NIST98 (National Institute of Standards) and Adam’s library spectra (Adams and Sparkman, 2007 ▶).

Antibacterial activity

The antimicrobial activity of the films was measured by the disc diffusion method. In aseptic conditions, 6 mm diameter discs were made from the films using punctures. The discs were placed on the surface of the nutrient agar plate inoculated with 0.1 ml of S. aurous and E. coli suspension (approximately containing 106 CFU/ml). The plates were then incubated at 37°C for 24 h. Then, the diameter of the inhibition zone around the discs was measured. Three independent replicates were carried out for each sample, with two duplicates (Jalaei et al., 2014 ▶).

Statistical analysis

A completely randomized design with a factorial arrangement was used for statistical analysis. Analysis of variance was performed using a general linear model (GLM) within the SAS package (SAS, 2013 ▶). Data were also analyzed by the repeated measurement method, and differences between means were tested using Duncan’s new multiple range test within the SAS package (SAS, 2013 ▶).

Results

Film characterization

SD

Figure 1 depicts the SD of MCH film. The highest SD was observed in MCH samples with a thickness of 260 µm after 48 h (P<0.05). The results indicated that the SD of MCH was increased by increasing the thickness and passing the time (P<0.05). The films have not reached equilibrium swelling after 48 h.

Fig. 1.

Fig. 1

Open in a new tab

Swelling degree (SD) of microchitosan (MCH) film in different thicknesses and time intervals. *: 90 µm, ▲: 125 µm, ♦: 175 µm, ■: 225 µm, and ●: 260 µm. n=3. Different letters indicate the significant difference between different thicknesses within each time (P<0.05)

Mechanical properties

The EB% and TS of MCH films are shown in Fig. 2. EB% had a linear relationship with the thickness of samples, which improved by increasing the thickness of films. The highest flexibility was observed in films with a thickness of 260 µm. The TS level of MCH with a thickness of 100-260 µm was less than 3.7 MPa, which is a conventional requirement for a food packaging material (Jeevahan and Chandrasekaran, 2019 ▶).

Fig. 2.

Fig. 2

Open in a new tab

Percentage of elongation at break (EB%) and tensile strength (TS) of different thicknesses of microchitosan (MCH) film. Different letters indicate the significant difference (P<0.05)

XRD analysis

The XRD patterns of the neat MCH and MCH films in two different thicknesses are presented in Figs. 3A-C. One peak was observed at 2θ = 20.22° in MCH films, and two sharp peaks were observed at 2θ = 10.50° and 20.22° in neat MCH. The percentage of crystallinity of neat MCH and MCH films with 125 and 175 µm thickness was 33.73, 28.25, and 23.22, respectively (Table 1).

Fig. 3.

Fig. 3

Open in a new tab

The X-ray diffraction (XRD) patterns of microchitosan films in different thicknesses (A: 125 µm, B: 175 µm, and neat microchitosan (C))

Table 1.

Crystallinity percentage of neat and films of microchitosan (MCH)

Microchitosan Sum of net area Sum of gross area Crystallinity
%
Neat 4692.14 13910.13 33.73
Film (thickness: 125 µm) 5397.72 19106.86 28.25
Film (thickness: 175 µm) 5198.44 22390.99 23.22
Open in a new tab

SEM analysis

The SEM image of the surface and cross section of MCH in different thicknesses is shown in Figs. 4A-D.

Fig. 4.

Fig. 4

Open in a new tab

Scanning electron microscope (SEM) images of the surface (A and C) and cross-section (B and D) morphology of microchitosan (MCH) film in low thickness (125 µm) and high thickness (175 µm), respectively

SEM of the films showed homogeneous dispersion of MCH in the starch matrix without any porosity. However, there was slight sedimentation in the films which could be related to the micro size of MCH and the presence of starch through the drying process (Vigneshwaran et al., 2006 ▶; Ma et al., 2016 ▶).

AFM analysis

Topographical images of three different scan sizes of two different thicknesses of MCH films are shown in Fig. 5. The roughness on the film surface can affect its mechanical and physical properties. AFM images presented that the thick MCH films had the highest projections and the roughest surfaces, so the MCH films with the highest thickness had rougher surfaces (Fig. 5). Table 2 summarizes the Sz, Sq, and Sa parameters of different thicknesses of MCH in three scan sizes. As shown, the low thickness of MCH films had the lowest Sq in all scan sizes.

Fig. 5.

Fig. 5

Open in a new tab

Topographic images of MCH films in different scan sizes of two different thickness. The images were obtained using a multimode atomic force microscope

Table 2.

Comparison of arithmetic mean of height (SZ), roughness (Sq), and average roughness (Sa) values of different scan sizes of two different thickness microchitosan films

Thickness (µm) Scan size (µm) Sz (nm) Sq (nm) Sa (nm)
125 3 × 3 73.9 10.3 7.85
5 × 5 138.0 14.6 10.7
10 × 10 186.0 24.6 19.0
175 3 × 3 64.0 14.0 11.5
5 × 5 88.5 21.4 17.3
10 × 10 182.0 41.0 33.3
Open in a new tab

Antibacterial activity

Main components of the EOs of Shirazi thyme and garlic as identified by GC/MS analysis are shown in Table 3. Thymol (39.14%) and carvacrol (26.61%) were the main components of Shirazi thyme EO. Diallyl disulfide (20.18%) and diallyl trisulfide (32.82%) were the main components of garlic EO.

Table 3.

Main components (%) of the essential oils (EOs) of Shirazi thyme (Zataria multiflora) and garlic (Allium sativum)

Compounds Shirazi thyme Garlic
α-Pinene 3.34 -
ρ-Cymen 7.88 -
γ-Terpinene 6.57 -
Thymol 39.14 -
Carvacrol 26.61 -
Caryophyllene 2.11 -
Allyl n-propyl sulfide - 3.53
3-Methylthiophene - 0.1
Allyl methyl disulfide - 7.18
Diallyl disulfide - 20.18
Diallyl trisulfide - 32.82
Open in a new tab

The antimicrobial effects of Shirazi thyme and garlic EOs alone and in combination against E. coli and S. aureus were evaluated.

Table 4 shows that there were no apparent inhibition zones around samples of MCH and MCH containing garlic EO for E. coli and S. aureus, but there were apparent inhibition zones against these bacteria around the films containing EO of Shirazi thyme. The inhibition zone against E. coli and S. aureus around the film with MCH containing EO of Shirazi thyme was much larger than that of the MCH containing both EOs. Briefly, MCH containing Shirazi thyme and Shirazi thyme + garlic EOs exhibited distinct antibacterial efficacy against S. aureus and E. coli.

Table 4.

Diameter of inhibition zone (mm) against E. coli and S. aureus around the microchitosan (MCH) films containing essential oils (EOs) of Shirazi thyme and garlic

Treatment groups Inhibition diameter (mm)
E. coli S. aureus
Control 0.0a 0.0a
Garlic EO 0.0a 0.0a
Thyme EO 12.3 ± 0.9b 42.0 ± 3.1b
Garlic + thyme EOs 8.5 ± 0.3c 35.8 ± 0.6c
Open in a new tab

The different letters indicate significant differences among treatment groups (P<0.05)

Discussion

The samples with a thickness of 260 µm were able to absorb water more than 14 times their weight. It seems that MCH can be a suitable and notable moisture absorbent pad for food packaging.

The optimized MCH improved mechanical properties compared with some synthetic films (Jeevahan and Chandrasekaran, 2019 ▶). It seems that improvement of the mechanical and elongation at break properties for the micro film is due to the cellulosic component through interfacial hydrogen and ionic interactions (Cao et al., 2008 ▶). This is attributed to the good interfacial interaction between the fillers and matrix, which was an important factor affecting the mechanical properties of the composites (Ma et al., 2009 ▶). Consequently, a suitable and equal distribution of applied stress reduces the stress concentrations and increases the flexibility of films (Kanagaraj et al., 2007 ▶; Chaichi et al., 2017 ▶). Frone et al. (2013) ▶ reported that the supplement of micro-fibrillated cellulose improved the elasticity modulus of biodegradable polymers of polylactic acid (PLA) XRD patterns and the crystallinity percentage showed that the MCH was present in the films at

different thicknesses. Also, the crystallinity degree of neat MCH was higher than that found for MCH films, which indicated that the amorphous structure of neat MCH was lower than the MCH films. An amorphous structure could increase the amount of moisture absorption of samples. Hence, the SD levels of MCH in thick samples were higher than in thin ones (Fig. 1).

Topographical images showed suitable dispersion of MCH in the starch matrix, indicating appropriate interaction between the filler and the matrix, which is in agreement with mechanical outcomes. As seen in Fig. 5, with increasing thickness, the presence of uneven plateaus on the AFM images increased and revealed more affinity for agglomerate. These are found to validate the finding of the SEM pictures. Mandal and Chakrabarty (2015) ▶ reported that at the higher level of biopolymer integration, the elements display an extra tendency to agglomerate, thus making micro or macro composites.

Shirazi thyme belongs to the Laminaceae family that grows in Iran, Pakistan, and Afghanistan, and this plant is widely used as a flavouring agent in several foods. Shirazi thyme has inhibitory activity on Gram-negative and Gram-positive bacteria due to having different amounts of phenolic compounds in leaves, flowers, and roots (Shirdel et al., 2017 ▶; Qin et al., 2019 ▶).

The antibacterial mechanism of garlic is due to the competitive inhibition of sulfhydryl-containing enzymes (specific inhibition of RNA synthesis and lipid biosynthesis) (Morales-González et al., 2019 ▶). Numerous studies have shown that garlic EO has antimicrobial effects against foodborne pathogens. Diallyl disulfide and diallyl trisulfide are the main components of garlic EO (WU et al., 2008), which are considered to be the main antimicrobial compounds of garlic EO (Yin and Cheng, 2003; Rattanachaikunsopon and Phumkhachorn, 2009 ▶). In the present study, a MCH film containing 2% garlic EO had no inhibitory effect on E. coli and S. aureus. In the study by Seydim and Sarikus (2006) ▶, a concentration of 2% of this EO along with whey protein-based edible films had no inhibitory effect against foodborne bacteria.

In the presence of EO of Shirazi thyme, the Gram-negative bacterial strains of E. coli had smaller inhibition zones than those of Gram-positive bacterial strains of S. aureus. This indicated that the E. coli strain exhibited higher resistance to Shirazi thyme than the S. aureus strain. The present results are consistent with the results that have worked on the antibacterial effects of films containing garlic and Shirazi thyme by many researchers (Rahimi et al., 2019 ▶; Qin et al., 2019 ▶).

This study prepared a starch-based film from MCH as a moisture-absorbing pad. The film had a considerable water absorption capacity, which increased with increasing the thickness and passing time. The film containing Shirazi thyme showed a clear antibacterial effect. The film can be described as a unique chitosan film, a moisture-absorbing antibacterial pad, and a new idea for active food packaging to increase the shelf life of foods with fully degradable properties.

Conflict of interest

The authors declare that they have no conflicts of interest.

Acknowledgements

The financial support was provided by Shiraz University, Iran. The Agricultural Research Education and Extension Organization (AREEO), the Animal Science Research Institute (ASRI), and the Agricultural Engineering Research Institute (AERI), Iran, are truly acknowledged.

References

  1. Adams RP, Sparkman OD. Review of identification of essential oil components by gas chromatography/mass spectrometry. J. Am. Soc. Mass Spectrom. 2007;18:803–806. [Google Scholar]
  2. Amidi M, Mastrobattista E, Jiskoot W, Hennink WE. Chitosan-based delivery systems for protein therapeutics and antigens. Adv. Drug. Deliv. Rev. 2010;62:59–82. doi: 10.1016/j.addr.2009.11.009. [DOI] [PubMed] [Google Scholar]
  3. Amjadi S, Emaminia S, Davudian SH, Pourmohammad S, Hamishehkar H, Roufegarinejad L. Preparation and characterization of gelatin-based nanocomposite containing chitosan nanofiber and ZnO nanoparticles. Carbohydr. Polym. 2019;216:376–384. doi: 10.1016/j.carbpol.2019.03.062. [DOI] [PubMed] [Google Scholar]
  4. ASTM International. Standard test methods for tensile properties of thin plastic sheeting. D882-02. Annual book of ASTM Standards. 14.02. United States; 2007. [Google Scholar]
  5. Bhardwaj A, Alam T, Talwar N. Recent advances in active packaging of agri-food products: a review. J. Postharvest Technol. 2019;07:33–62. [Google Scholar]
  6. Cao X, Chen Y, Chang PR, Stumborg M, Huneault MA. Green composites reinforced with hemp nanocrystals in plasticized starch. J. Appl. Polym. Sci. 2008;109:3804–3810. [Google Scholar]
  7. Chaichi M, Hashemi M, Badii F, Mohammadi A. Preparation and characterization of a novel bio nanocomposite edible film based on pectin and crystalline nanocellulose. Carbohydr. Polym. 2017;157:167–175. doi: 10.1016/j.carbpol.2016.09.062. [DOI] [PubMed] [Google Scholar]
  8. Chanphai P, Tajmir-Riahi HA. Conjugation of tea catechins with chitosan nanoparticles. Food Hydrocoll. 2018;84:561–570. [Google Scholar]
  9. FICCI (Federation of Indian Chambers of Commerce and Industry) A report on plastics industry. In: Proceedings of the 2nd National Conference on Plastic Packaging-the Sustainable Choice. New Delhi: 2016. [Google Scholar]
  10. Frone AN, Berlioz S, Chailan JF, Panaitescu DM. Morphology and thermal properties of PLA-cellulose nanofibers composites. Carbohydr. Polym. 2013;91:377–384. doi: 10.1016/j.carbpol.2012.08.054. [DOI] [PubMed] [Google Scholar]
  11. Jalaei J, Fazeli M, Rajaian H, Shekarforoush SS. In vitro antibacterial effect of wasp (Vespa orientalis) venom. J. Venom. Anim. Toxins Incl. Trop. Dis. 2014;20:1–6. doi: 10.1186/1678-9199-20-22. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Jeevahan J, Chandrasekaran M. Nanoedible films for food packaging: a review. J. Mater Sci. 2019;54:12290–12318. [Google Scholar]
  13. Kanagaraj S, Varanda FR, Zhiltsova TV, Oliveira MS, Simoes JAO. Mechanical properties of high-density polyethylene/carbon nanotube composites. Compos. Sci. Technol. 2007;67:3071–3077. [Google Scholar]
  14. Koo JH. Polymer nanocomposites: Processing, characterization, and applications. 2nd Edn. 2019;New York, McGraw-Hill Education:272. [Google Scholar]
  15. Kumar MNVR. A review of chitin and chitosan applications. React. Funct. Polym. 2000;46:1–27. [Google Scholar]
  16. Lavorgna M, Piscitelli F, Mangiacapra P, Buonocore GG. Study of the combined effect of both clay and glycerol plasticizer on the properties of chitosan films. Carbohyd. Polym. 2010;82:291–298. [Google Scholar]
  17. Ma X, Chang PR, Yang J, Yu J. Preparation and properties of glycerol plasticized-pea starch/zinc oxide-starch bionanocomposites. Carbohyd. Polym. 2009;75:472–478. [Google Scholar]
  18. Ma J, Zhu W, Tian Y, Wang Z. Preparation of zinc oxide-starch nanocomposite and its application on coating. Nanoscale Res. Lett. 2016;11:1–9. doi: 10.1186/s11671-016-1404-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mandal A, Chakrabarty D. Characterization of nanocellulose reinforced semi-interpenetrating polymer network of poly (vinyl alcohol) and polyacrylamide composite films. Carbohyd. Polym. 2015;134:240–250. doi: 10.1016/j.carbpol.2015.07.093. [DOI] [PubMed] [Google Scholar]
  20. Mohamad NA, Fahmy MM. Synthesis and antimicrobial activity of some novel cross-linked chitosan hydrogels. Int. J. Mol. Sci. 2012;13:11194–11209. doi: 10.3390/ijms130911194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Morales-González JA, Madrigal-Bujaidar E, Sánchez-Gutiérrez M, Izquierdo-Vega JA, Valadez-Vega MC, Álvarez-González I, Morales-González A, Madrigal-Santillán E. Garlic (Allium sativum): A brief review of its antigenotoxic effects. Foods. 2019;8:343. doi: 10.3390/foods8080343. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Noorbakhsh-Soltani SM, Zerafat MM, Sabbaghi S. A comparative study of gelatin and starch-based nano-composite films modified by nano-cellulose and chitosan for food packaging applications. Carbohyd. Polym. 2018;189:48–55. doi: 10.1016/j.carbpol.2018.02.012. [DOI] [PubMed] [Google Scholar]
  23. Ozdemir M, Floros JD. Active food packaging technologies. Criti. Rev. Food Nutr. 2004;44:185–193. doi: 10.1080/10408690490441578. [DOI] [PubMed] [Google Scholar]
  24. Qin Y, Liu Y, Yuan L, Yong H, Liu J. Preparation and characterization of antioxidant, antimicrobial and pH-sensitive films based on chitosan, silver nanoparticles and purple corn extract. Food Hydrocoll. 2019;96:102–111. [Google Scholar]
  25. Rahimi R, ValizadehKaji B, Khadivi A, Shahrjerdi I. Effect of chitosan and thymol essential oil on quality maintenance and shelf-life extension of peach fruits cv. ‘Zaferani’. J. Hortic. Postharvest Res. 2019;2:143–156. [Google Scholar]
  26. Rattanachaikunsopon P, Phumkhachorn P. Shallot (Allium ascalonicum L oil: Diallyl sulfide content and antimicrobial activity against food-borne pathogenic bacteria. Afr. J. Microbiol. Res. 2009;3:747–750. doi: 10.1271/bbb.80482. [DOI] [PubMed] [Google Scholar]
  27. Ribeiro MC, Correa VLR, da Silva FKL, de Oliveira Neto JR, Casas AA, de Menezes LB, Amara AC. Improving peptide quantification in chitosan nanoparticles. Int. J. Biol. Macromol. 2018;119:32–36. doi: 10.1016/j.ijbiomac.2018.07.119. [DOI] [PubMed] [Google Scholar]
  28. SAS. Proprietary Software Version 9.00. SAS Institute. Cary, NC, USA; 2013. [Google Scholar]
  29. Schiffman JD, Schauer CL. One-stepelectrospinning of crosslinked chitosan fibers. Biomacromolecules. . 2007;8:2665–2667. doi: 10.1021/bm7006983. [DOI] [PubMed] [Google Scholar]
  30. Seydim AC, Sarikus G. Antimicrobial activity of whey protein based edible films incorporated with oregano, rosemary and garlic essential oils. Food Res. Int. 2006;39:639–644. [Google Scholar]
  31. Shirdel M, Tajik H, Moradi M. Combined activity of colloid nanosilver and Zataria nultiflora Boiss essential oil mechanism of action and biofilm removal activity. Adv. Pharm. Bull. 2017;7:621–628. doi: 10.15171/apb.2017.074. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Silva F, Domingues FC, Nerín C. Control microbial growth on fresh chicken meat using pinosylvin inclusion complexes-based packaging absorbent pads. LWT-Food Sci. Technol. 2018;89:148–154. [Google Scholar]
  33. Sun X, Jia P, Zhe T, Bu T, Liu Y, Wang Q, Wang L. Construction and multifunctionalization of chitosan-based three-phase nano-delivery system. Food Hydrocoll. 2019;96:402–411. [Google Scholar]
  34. Turalija M, Bischof S, Budimir A, Gaan S. Antimicrobial PLA films from environment friendly additives. Compos. B. Eng. 2016;102:94–99. [Google Scholar]
  35. van der Lubben IM, Verhoef JC, Borchard G, Junginger HE. Chitosan and its derivatives in mucosal drug and vaccine delivery. Eur. J. Pharm. Sci. 2001;14:201–207. doi: 10.1016/s0928-0987(01)00172-5. [DOI] [PubMed] [Google Scholar]
  36. Vigneshwaran N, Kumar S, Kathe AA. Functional finishing of cotton fabrics using zinc oxide-soluble starch nanocomposites. Nanotechnology. . 2006;17:5087–5095. [Google Scholar]
  37. Wei D, Sun W, Qian W, Ye Y, Ma X. The synthesis of chitosan-based silver nanoparticles and their antibacterial activity. Carbohydr. Res. 2009;344:2375–2382. doi: 10.1016/j.carres.2009.09.001. [DOI] [PubMed] [Google Scholar]
  38. Yang YN, Lu KY, Wang P, Ho YC, Tsai ML, Mi FL. Development of bacterial cellulose/chitin multi-nanofibers based smart films containing natural active microspheres and nanoparticles formed in situ. Carbohydr. Polym. 2020;228:115370. doi: 10.1016/j.carbpol.2019.115370. [DOI] [PubMed] [Google Scholar]
  39. Yin MC, Cheng WS. Antioxidant and antimicrobial effects of four garlic-derived organosulfur compounds in ground beef. Meat Sci. 2003;63:23–28. doi: 10.1016/s0309-1740(02)00047-5. [DOI] [PubMed] [Google Scholar]

Articles from Iranian Journal of Veterinary Research are provided here courtesy of Shiraz University

RESOURCES