This study focuses on changes in the physiochemical properties of chitosan film when incorporated with a blend of essential oils of Tulsi and Ajwain. The essential oil blend-loaded films showed a ...decrement in transparency. Tulsi essential oil decreased the moisture content, swelling capacity, and water solubility. However, adding Ajwain along with Tulsi essential oil led to a significant increase in these properties. Meanwhile, the water vapor transmission rate didn't change significantly due to non-polar constituents in Tulsi essential oil, except when only Ajwain essential oil was present. The mechanical properties showed that the tensile strength of films increased with the addition of Tulsi essential oil (14.95 MPa to 31.27 MPa) but decreased further with increasing Ajwain oil concentration in films (32.13 MPa to 15.89 MPa). On the other hand, an increment in percent elongation at break (8.26 % to 24.02 %) was observed due to the excellent plasticization effect of Ajwain essential oil. Antioxidant activity was observed for the Tulsi essential oil-containing films and increased significantly with adding Ajwain essential oil. Finally, walnuts were packed in the active film. The active film showed better antioxidant activity against the oxidation of oil in walnuts, which the FTIR of the packed product confirmed.
Citrus EOs is an economic, eco-friendly and natural alternatives to chemical preservatives and other synthetic antioxidants, such as sodium nitrites, nitrates or benzoates, commonly utilized in food ...preservation. Citrus based EOs is obtained mainly from the peels of citrus fruits which are largely discarded as wastes and cause environmental problems. The extraction of citrus oils from the waste peels not only saves environment but can be used in various applications including food preservation. The present article presents elaborated viewpoints on the nature and chemical composition of different EOs present in main citrus varieties widely grown across the globe; extraction, characterization and authentication techniques/methods of the citrus EOs; and reviews the recent advances in the application of citrus EOs for the preservation of fruits, vegetables, meat, fish and processed food stuffs. The probable reaction mechanism of the EOs based thin films formation with biodegradable polymers is presented. Other formulation, viz., EOs microencapsulation incorporating biodegradable polymers, nanoemulsion coatings, spray applications and antibacterial action mechanism of the active compounds present in the EOs have been elaborated. Extensive research is required on overcoming the challenges regarding allergies and obtaining safer dosage limits. Shift towards greener technologies indicate optimistic future towards safer utilization of citrus based EOs in food preservation.
The current study aimed to investigate the efficacy of dietary thyme essential oil (TEO),
Nigella sativa
essential oil (NSEO), thyme essential oil nano-emulsion (TEO-NE), and
Nigella sativa
essential ...oil nano-emulsion (NSEO-NE) in reducing total ammonia nitrogen (TAN), improving immune response, mitigating stress, and acting as anti-inflammatory agents as well as preventing streptococcosis infection in
Oreochromis niloticus
(
O. niloticus)
. Fish (
N
= 330, 14 ± 2 g) were divided into 10 groups of 11 fish each, with three replicates in each group. The negative and positive controls were fed a control diet, while the third group was given 1% TEO. Moreover, the fourth group of fish was given 2% TEO. The fifth and sixth groups were fed 1% TEO-NE and 2% TEO-NE, respectively. The seventh, eighth, ninth, and tenth groups were fed 1% NSEO, 2% NSEO, 1% NSEO-NE, and 2% NSEO-NE, respectively. After dietary intake of TEO, NSEO, and their nano-emulsions for 28 days, the mean values of TAN levels in the water of fish aquaria had a significant reduction in the group fed 2% TEO-NE compared to the control group. On the contrary, NSEO-NE at the same concentration had no significant effect on TAN levels. The levels of lysozyme, complement 5, and IgM increased in all feeding groups compared to the control group. Concerning cortisol level as a stress indicator, it was decreased in all feeding groups compared to the control. Also, the current experiment overall showed a significant decrease in the expression level of pro-inflammatory tumor necrosis factor (TNF-α) gene in the gills of fish groups fed TEO, TEO-NE, NS, and NS-NE relative to the β-actin gene. Oppositely, there was an increase in the expression level of the anti-inflammatory transforming growth factor (TGF-β). In the current study, TEO-NE and NSEO-NE showed a better effect on preventing streptococcosis in
O. niloticus
with no mortality than 1% TEO and NSEO, respectively. Furthermore, there was a 12.5% mortality rate and an 84.99 RPS in the group fed 1% TEO and injected with
Streptococcus inae
. On the other hand, the groups fed 1 and 2% NSEO showed 37.5 and 25% mortality rate, respectively and 54.99 and 69.99 RPS. In conclusion, the nano-emulsion either TEO or NSEO had the superior effect. For bulk status, the TEO had superior effect than NSEO. The study needs more investigations for ammonia, either on the mode of action or over a longer period.
The present study evaluated the housefly repellency of single-component formulations and combinations of lemongrass and star anise essential oils (EOs) and their main constituents. The efficacies of ...the combinations were compared against those of single-component formulations and DEET. Safety bioassays of all formulations and DEET on non-target species-guppy, molly, dwarf honeybee, and stingless bee-were conducted. GC-MS analysis showed that the main constituent of lemongrass EO was geranial (46.83%) and that of star anise EO was
-anethole (92.88%). All combinations were highly synergistic compared to single-component formulations, with an increased repellent value (IR) of 34.6 to 51.2%. The greatest synergistic effect was achieved by 1.0% lemongrass EO + 1.0%
-anethole combination, with an IR of 51.2%. The strongest, 100% repellent rate at 6 h was achieved by 1.0% geranial + 1.0%
-anethole. They were twice as effective as DEET and caused obvious damage to housefly antennae under microscopic observation. All single-component formulations and combinations were benign to the four tested non-target species. In contrast, DEET was highly toxic to them. The synergistic repellency and biosafety of these two combinations are compellingly strong support for developing them into an effective green repellent.
Tea tree oil (TTO) is a volatile essential oil obtained by distillation, mainly from the Australian native plant Melaleuca alternifolia (Maiden & Betche) Cheel (Myrtaceae). In this study, a ...comparative analysis of the chemical constituents of seven tea tree oils (M. alternifolia) and four other Melaleuca spp. oils (M. cajuputi, (Msub.Ca), two chemotypes of M. quinquenervia, (Msub.Ne and Msub.Ni), and M. ericifolia (Msub.Ro)) was carried out using gas chromatography–mass spectrometry (GC-MS) and high-performance thin-layer chromatography (HPTLC). Among the seven TTOs, terpinen-4-ol (37.66–44.28%), γ-terpinene (16.42–20.75%), α-terpinene (3.47–12.62%), α-terpineol (3.11–4.66%), and terpinolene (2.75–4.19%) were the most abundant compounds. On the other hand, the most abundant compounds of the other Melaleuca oils varied, such as 1,8-cineole (64.63%) in Msub.Ca oil, (E)-nerolidol (48.40%) and linalool (33.30%) in Msub.Ne oil, 1,8-cineole (52.20%) in Msub.Ni oil, and linalool (38.19%) and 1,8-cineole (27.57%) in Msub.Ro oil. HPTLC fingerprinting of Melaleuca oils enabled the discrimination of TTO oils from other Melaleuca spp. oils. Variation was observed in the profile of the Rsub.f values among EOs. The present study shows that HPTLC is one of the best ways to identify and evaluate the quality control in authenticating TTOs, other Melaleuca EOs, or EOs from other species within the Myrtaceae.
Carvacrol and human health: A comprehensive review Sharifi‐Rad, Mehdi; Varoni, Elena Maria; Iriti, Marcello ...
PTR. Phytotherapy research/Phytotherapy research,
September 2018, Volume:
32, Issue:
9
Journal Article
Peer reviewed
Open access
Carvacrol (CV) is a phenolic monoterpenoid found in essential oils of oregano (Origanum vulgare), thyme (Thymus vulgaris), pepperwort (Lepidium flavum), wild bergamot (Citrus aurantium bergamia), and ...other plants. Carvacrol possesses a wide range of bioactivities putatively useful for clinical applications such antimicrobial, antioxidant, and anticancer activities. Carvacrol antimicrobial activity is higher than that of other volatile compounds present in essential oils due to the presence of the free hydroxyl group, hydrophobicity, and the phenol moiety. The present review illustrates the state‐of‐the‐art studies on the antimicrobial, antioxidant, and anticancer properties of CV. It is particularly effective against food‐borne pathogens, including Escherichia coli, Salmonella, and Bacillus cereus. Carvacrol has high antioxidant activity and has been successfully used, mainly associated with thymol, as dietary phytoadditive to improve animal antioxidant status. The anticancer properties of CV have been reported in preclinical models of breast, liver, and lung carcinomas, acting on proapoptotic processes. Besides the interesting properties of CV and the toxicological profile becoming definite, to date, human trials on CV are still lacking, and this largely impedes any conclusions of clinical relevance.
species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be ...found in their fruits, seeds, leaves, branches, roots and stems. Some
species have simple chemical profiles, while others, such as
,
, and
, contain very diverse suites of secondary metabolites. In traditional medicine,
species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition,
species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of
species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover,
species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of
plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of
species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils
plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.
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