Incorporation Of Oregano Essential Oil Research Articles

Oregano essential oil/β-cyclodextrin inclusion compound polylactic acid/polycaprolactone electrospun nanofibers for active food packaging

In this study, polylactic acid (PLA) and polycaprolactone (PCL) electrospun nanofibers with added oregano essential oil (OEO)–loaded β-cyclodextrin (β-CD) were developed as an active food packaging material. After the incorporation of OEO@β-CD, the obtained electrospun fibers were continuous nanofibers with an average diameter range of 1321–1802 nm, and the OEO@β-CD was encapsulated in the nanofibers. The OEO@β-CD/PLA/PCL nanofibers exhibited enhanced thermal stability and anti-deformation capacity, but impaired tensile strength. Furthermore, the incorporation of OEO@β-CD induced an impaired hydrophobic surface caused by the formation of hydrogen bonds but did not change water vapor barrier property. In addition, OEO@β-CD/PLA/PCL nanofibers showed antibacterial and antifungal capacity. The co-culture of nanofibers with zebrafish demonstrated biosafety of fibrous membranes. During the application experiment, OEO@β-CD/PLA/PCL nanofibers delayed postharvest decay, deterioration, and storage quality loss in blackberry, demonstrating the significant potential for use of these fibers as an active food packaging material.

Physical, Morphological, Structural, Thermal and Antimicrobial Characterization of Films based on Poly(Lactic Acid), Organophilic Montmorillonite and Oregano Essential Oil

This work developed ternary films based on Poly(Lactic Acid) (PLA), Cloisite 30B (C30B) and Oregano Essential Oil (OEO) as proposal to be applied in food packaging. The films thus manufactured were unscathed, with reduced surface defects. Their thickness and moisture content varied according to the composition and content of each component in the formulation. Optical micrographs indicated a homogeneous morphology, with good distribution of clay in the matrix. FTIR data confirms the incorporation of OEO into the films. TGA analysis indicated that the thermal stability of the films was not significantly affected by the incorporation of C30B and OEO. OEO incorporation did not promote an efficient antimicrobial action which is probably due to its retention by the clay. Further studies are needed to confirm this hypothesis. The combination between C30B and OEO in the PLA polymeric matrix is a promising proposal.

Combined Effect of Chitosan-Based Edible Film Containing Oregano Essential Oil on the Shelf-Life Extension of Fresh Chicken Meat

Background: The aim of this study was to investigate the effects of chitosan coatings, oregano essential oil, and their combination on microbial quality of chicken fillet during 12 days in refrigerator temperature. Methods: Oregano oil was extracted by water distillation and then different concentrations of oregano oil (1% and 2%) were used for film preparation. Microbiological tests were carried out on the chicken fillet samples stored in 4 °C at different intervals including days 0, 3, 6, 9, and 12. Results: Treated groups with chitosan and oregano oil affected the increase rate of aerobic plate counts, coliform counts, and total psychrophilic counts significantly compared to the control group across the entire storage period (P < 0.05). Chitosan-based edible film containing oregano oil inhibited microbial growth on chicken fillet. Microbial populations were reduced by 2.14-3.53 log CFU/g in groups treated with chitosan and oregano oil. Our results revealed that incorporation of oregano essential oil at 2% concentration had the highest inhibitory effect on spoilage microorganisms in coated chicken fillet during 12 days of storage at refrigerator. Conclusion: Generally, application of oregano essential oil at 2% concentration had the potential to enhance safety and shelf-life of chicken fillet.

Use of micronucleus and comet assay to evaluate evaluate the genotoxicity of oregano essential oil (Origanum vulgare l. Virens) in rats orally exposed for 90 days.

ABSTRACTEssential oils from Origanum spp. exhibit antioxidant and antimicrobial activities making them suitable for use as food additives. The incorporation of oregano essential oil in active food packaging is under study; however, it has been not authorized for this purpose thus far. In order to fulfill the requirements of the European Food Safety Authority (EFSA), the aim of the present study was to determine the genotoxic potential of oregano essential oil using both the micronucleus (MN) test and comet (standard and enzyme-modified) assays in Wistar rats treated with 50, 100, or 200 mg/kg body weight administered daily for 90 days. MN was performed in cells from the bone marrow and standard and enzyme-modified comet assays were conducted in stomach, liver and blood cells. The major compound detected in the analytical study of oregano essential oil from Origanum vulgare L. virens, was carvacrol (55.82%) followed by thymol (5.14%), as well as their precursors, γ-terpinene (16.39%), and ρ-cimne (4.71%). The results obtained in the genotoxicity assays indicated lack of effect in MN and standard comet assay under the conditions tested. Furthermore, no apparent oxidative damage was observed in the enzyme-modified comet assay in any of the tissues examined of rats exposed to oregano essential oil for 90 days. Therefore, this oregano essential oil appears to be safe in Wistar rats and might be considered as a potential active material in food packaging industry.

Characterization of novel basil-seed gum active edible films and coatings containing oregano essential oil

Basil seed gum (BSG) edible films containing oregano essential oil (OEO) (1–6%) were fabricated and evaluated for antibacterial activity against E. coli, S. Typhimurium, P. aeruginosa, S. aureus and B. cereus, as well as antioxidant activity, film thickness, moisture content, transparency, swelling index, contact angle and water vapor permeability (WVP). The thickness of BSG based film was recorded as 0.06 mm; the increase in OEO concentration did not change the thickness significantly (p > 0.05). The WVP was decreased significantly by incorporation of OEO while the moisture content, contact angle, transparency and swelling index (p < 0.05) of edible films were increased. All films containing 2–6% OEO presented a significant antibacterial activity against the examined pathogens. The DPPH and ABTS radical scavenging activities and ferric reducing ability of BSG films were enhanced considerably with increasing OEO concentration. According to results, the fabricated edible films with BSG and OEO can be considered for further approaching as an edible food packaging.

Application of Edible Films Containing Oregano (Origanum vulgare) Essential Oil on Queso Blanco Cheese Prepared with Flaxseed (Linum usitatissimum) Oil.

Fortification of queso blanco (QB) with flaxseed oil (FO) containing omega-3 polyunsaturated fatty acids may provide a functional food with health benefits such as improved cell, brain, and retina functionality, and protection against cardiovascular and immune-inflammatory diseases. However, QB experiences a short shelf life because of the early development of yeasts and molds and addition of FO may increase susceptibility to lipid oxidation. Oregano essential oil (OEO) is known for its antimicrobial and antioxidant properties, but due to its intense flavor compounds it may not be suitable for direct incorporation into QB. Thus, incorporation of OEO into an edible film prepared with whey protein isolate (WPI) may improve the shelf life of QB. Scanning electron microscopy (SEM) micrographs revealed that FO was successfully retained by the cheese after homogenization. The thiobarbituric-acid-reactive-substances (TBARS) and yeast and mold counts (YMC) of the wrapped cheeses were analyzed during 60 d of refrigerated storage. The oxidation rate increased significantly for nonwrapped QB containing FO (QBFO) during storage, however wrapping with WPI edible films containing OEO (WOF) significantly limited lipid oxidation and prevented growth of yeasts and molds. This study demonstrated the antioxidant and antimicrobial properties of WOF for preservation of QBFO during refrigerated storage.

Characterization of Active Packaging Films Made from Poly(Lactic Acid)/Poly(Trimethylene Carbonate) Incorporated with Oregano Essential Oil.

Antimicromial and antioxidant bioactive films based on poly(lactic acid)/poly(trimenthylene carbonate) films incorporated with different concentrations of oregano essential oil (OEO) were prepared by solvent casting. The antimicrobial, antioxidant, physical, thermal, microstructural, and mechanical properties of the resulting films were examined. Scanning electron microscopy analysis revealed that the cross-section of films became rougher when OEO was incorporated into PLA/PTMC blends. Differential scanning calorimetry analysis indicated that crystallinity of PLA phase decreased by the addition of OEO, but this did not affect the thermal stability of the films. Water vapor permeability of films slightly increased with increasing concentration of OEO. However, active PLA/PTMC/OEO composite films showed adequate barrier properties for food packaging application. The antimicrobial and antioxidant capacities were significantly improved with the incorporation of OEO (p < 0.05). The results demonstrated that an optimal balance between the mechanical, barrier, thermal, antioxidant, and antimicrobial properties of the films was achieved by the incorporation of 9 wt % OEO into PLA/PTMC blends.

Oregano Essential Oil and Carvacrol reduce Cryptosporidium parvum infectivity of HCT‐8 Cells

Lipid‐based nutrition supplements (LNS) are commonly used to treat moderate acute undernutrition in children. However, existing LNS products mainly focus on providing nutrients and do not address other immediate causes of undernutrition, such as parasitic infection and gut inflammation. Enteric parasites are known to reduce nutrient digestion and absorption, cause chronic gut inflammation, iron deficiency anemia, protein‐energy malnutrition, and reduce growth and cognitive development in children. Oregano essential oil (OEO) is known to have anti‐bacterial and anti‐fungal activity, however its anti‐parasitic properties are poorly understood. This study systemically investigated the effect of OEO and its main bioactive, carvacrol (CV), on prevention of Cryptosporidium parvum infectivity of HCT‐8 (human colon carcinoma) cells in vitro, for potential incorporation of these bioactives into LNS products. HCT‐8 cells were seeded (1 × 106) in 96‐well microtiter plates until confluency (2 days). HCT‐8 cell viability at various concentrations of either OEO or CV was measured using a Live/Dead cell imaging kit. Confluent HCT‐8 cell monolayers were seeded with C. parvum oocytes (1 × 104) in two modalities: 1) 4 h co‐culture of C. parvum oocysts, cells and several dosages (0 μg/mL to 250 μg/mL) of CV or OEO in complete medium, followed by PBS washing and replacement with bioactive‐free media; and 2) 4 h co‐culture of C. parvum oocysts and cells alone, followed by PBS washing and treatment with several dosages (0 μg/mL to 250 μg/mL) of CV or OEO. In either modality, plates were incubated at 37°C and 5% CO2, and after 2‐day incubation, cells and C. parvum were fixed with methanol: acetic acid solution (9:1 v/v). Infectivity was assessed via immunofluorescence detection using C. parvum‐specific antibody staining (Sporo‐Glo™) and phase contrast/fluorescent microscopy. Deformation of cell monolayers and loss of cell viability was found at 50 μg/mL CV, whereas no loss in cell viability was observed in cells treated with OEO at dosages as high as 125 μg/mL (containing similar concentrations of CV). In modality 1 experiments, cells simultaneously treated with C. parvum and various dosages of OEO or CV presented similar amounts of infection after 4 h incubation as those cells treated with C. parvum alone. In modality 2 experiments, after 2‐day treatment with bioactives, a 50% reduction in C. parvum infectivity was observed at 25 μg/mL of CV and at 125 μg/mL of OEO. C. parvum is one of the most resilient enteric parasites and prevalent in most of the developing world. Incorporation of OEO or CV into LNS formulas may provide double benefit to at risk populations afflicted by undernutrition and gut infection living in low‐income settings.Support or Funding InformationIndian Council of Agricultural Research (ICAR), India

Properties and antimicrobial activity of silver carp (Hypophthalmichthys molitrix) skin gelatin-chitosan films incorporated with oregano essential oil for fish preservation

Abstract Silver carp skin gelatin-chitosan films incorporated with different concentrations of oregano essential oil (OEO) were prepared and characterized. Results showed that OEO had the best antimicrobial activity among oregano, cinnamon and anise essential oil against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Bacillus enteritidis and Shigabacillus. The incorporation of OEO into gelatin-chitosan film clearly improved antimicrobial activity. As regard to the film properties, the addition of OEO into gelatin-chitosan film significantly reduced mechanical property and increased light barrier, water vapor barrier. Film solubility of gelatin-chitosan film significantly decreased when containing 4% OEO (p ≤ 0.05). The SEM result revealed gelatin-chitosan-OEO film had rough cross-section. FTIR spectra indicated that no new bonds were formed in gelatin-chitosan-OEO film. For fish preservation, total aerobic plate count and total volatile basic nitrogen values of fish muscle samples which packaged with gelatin-chitosan film incorporated with 4% OEO were significantly lower than those samples packaged with parafilm and control. These results indicated that the gelatin-chitosan film incorporated with OEO has the potential to extend the shelf-life of fish muscle.

Quince seed mucilage films incorporated with oregano essential oil: Physical, thermal, barrier, antioxidant and antibacterial properties

Quince seed mucilage (QSM) films containing oregano essential oil at 1, 1.5 and 2% v/v were prepared to examine their antibacterial, antioxidant, physical, thermal, microstructural and mechanical properties. Addition of 1% oregano essential oil did not affect the oxygen and water vapor permeability of the films. Incorporating OEO, increased total color differences (ΔE) and decreased whiteness index (WI). A decrease of elastic modulus (EM) and tensile strength (TS) accompanied with an increase in elongation at break (%EB) was observed with increasing oil concentration up to a level of 2.0% (w/w). Antimicrobial and antioxidant properties significantly increased with the incorporation of EO (p < 0.05). The antimicrobial activity of the QSM films incorporated with oregano essential oil was screened against 11 important food-related bacterial strains by agar disc-diffusion assay. Films containing 1% of OEO were not effective against Salmonella typhimurium and Pseudomonas aeruginosa but exhibited a strong inhibitory effect on the growth of Staphylococcus aureus, Escherichia coli, Shewanella putrefaciens and Yersinia enterocolitica as evidenced by minimal growth around the film cuts. Our results pointed out that the incorporation of oregano essential oil as a natural antibacterial agent has potential for using the developed film as an active packaging.

Physical, mechanical and antibacterial properties of alginate film: Effect of the crosslinking degree and oregano essential oil concentration

Alginate films with different degrees of crosslinking obtained by internal gelation, and alginate films incorporated with oregano essential oil (OEO) were prepared. The impact of the degree of crosslinking caused by the use of calcium carbonate as crosslinking agent and the incorporation of OEO into the alginate films on their antibacterial, optical, mechanical, microstructural and water vapour barrier properties was evaluated.An increase in the degree of crosslinking produced alginate films that were significantly thicker (0.031–0.038mm) and stronger (51.9–52.9MPa) but less elastic (2.3%) than those non-crosslinked films (0.029mm; 39.7MPa; 4.4%). The water vapour permeability (WVP) of the films decreased significantly only with the highest level of crosslinking.The incorporation of OEO in alginate films affected significantly their physical properties. Thickness and percent elongation at break of the films were increased by the addition of OEO (0.036–0.042mm and 2.7–3.7%), while the tensile strength and water vapour permeability decreased (31.1–55.5MPa and 2.7–3.0×10−9g/msPa).Films incorporated with OEO were more effective against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) than Gram-negative bacteria (Escherichia coli and SalmonellaEnteritidis). A minimum concentration of 1.0% of OEO was necessary to ensure their antibacterial efficacy.

Chitosan–Whey Protein Isolate Composite Films for Encapsulation and Stabilization of Fish Oil Containing Ultra Pure Omega‐3 Fatty Acids

Chitosan (1.5%, w/v)-whey protein isolate (WPI, 5% w/v) composite films were developed for encapsulating and stabilizing fish oil (FO) containing 93.7% eicosapentaenoic acid (EPA). Chitosan-WPI film-forming solutions (FFS) were incorporated with 1.5% or 2% FO (w/v), 2% (w/v) glycerol, Tween 80 (3 times weight of FO), and 0.5% (w/v) oregano or rosemary essential oil (EO), and cast for films at room conditions. Dried films were stored at 2 °C for 30 d for evaluating encapsulation efficiency (EE), lipid stability, and film functionality. Total oil contents in films from FFS incorporating 1.5% or 2% FO were 28.1% to 32.5% and 33.4% to 37.3%, respectively, and free oil contents were 13.5% to 14.7% and 15.5% to 16.3%, respectively. EE, moisture content, and water activity of the films were 47.8% to 66%, 18.7% to 24.9%, and 0.42% to 0.50%, respectively, without significant difference among differently formulated films. Increasing FO concentration from 1.5% to 2% in FFS decreased tensile strength of the films from 0.57-0.73 to 0.34-0.44 MPa, but not the film elongation. Addition of oregano EO in FFS retarded lipid oxidation of the fish oil encapsulated in the films, in which a 43% to 53% reduction in thiobarbituric acid-reactive substances value and 39% to 51% reduction in peroxide value were achieved. Chitosan-WPI composite films with incorporation of oregano essential oil could be applied as a simple and economic means for encapsulating and stabilizing fish oil for fortifying omega-3 fatty acids in various applications.

Effect of dietary oregano oil supplementation on lamb meat characteristics

The effect of dietary oregano essential oil supplementation on lamb meat characteristics was investigated. Eight male and eight female Chios lambs were divided into two equal groups. The first group was fed with the control diet consisting of concentrated feed and alfalfa hay, whereas the second group consumed the same diet, the only difference being that the concentrated feed was uniformly sprayed with oregano essential oil (1 ml/kg). Duration of the experimental period was two months. No differences were observed after oregano essential oil supplementation in final body weight (kg), body weight gain (g) and carcass yield (%). Tenderness of longissimus thoracis muscle, expressed as sarcomere length and shear force value, was not influenced by the treatment, whereas pH and colour parameters (yellowness–redness) appeared to increase ( P < 0.05). Moreover, results showed that dietary incorporation of oregano essential oil exerted strong antioxidant effects retarding lipid oxidation (MDA formation) in meat during refrigerated and long-term frozen storage ( P < 0.001).