Chitosan Nanoemulsion Research Articles

Efficacy of Pogostemon cablin essential oil loaded chitosan nanoemulsion as novel coating agent for inhibition of potato sprouting and maintenance of storage quality

Application of synthetic compounds to inhibit potato sprouting is a major challenge in the storage conditions. The replacement of synthetic compounds by essential oils for inhibition of potato sprouting is of current research hotspot. This is the first time investigation on encapsulation of Pogostemon cablin essential oil into chitosan nanoemulsion (Ne-PCEO) and its application as coating agent for anti-sprouting activity of potato tubers. The Ne-PCEO was characterized through SEM, DLS, FTIR, and XRD assay along with controlled delivery of PCEO. The Ne-PCEO coating inhibited in-vivo potato sprouting and regulated gibberellins (GA3) and aminocyclopropane-1-carboxylate (ACC) content along with impediment of respiration rate over 90 days of storage at 25 ± 2 °C (RH ∼ 70 %). The Ne-PCEO coating also prevented the weight loss, starch degradation, and increased the reducing sugar content of tubers without affecting the sensory qualities (p < 0.05), which strongly recommends its potential application as novel anti-sprouting coating agent for maintenance of potato storage quality.

Assessment of chitosan coating enriched with Citrus limon essential oil on the quality characteristics and shelf life of beef meat during cold storage

The present work aimed to assess the effects of chitosan coating comprising Citrus limon essential oil (CLEO) as an antimicrobial and antioxidant on the quality and the shelf-life of beef meat during storage in cold temperatures. The microbial, chemical, and sensory characteristics of beef meat were repeatedly evaluated. The outcomes showed that CLEO had a substantial preservative effect on refrigerated beef meat by reducing total volatile basic nitrogen compounds (TVB-N), inhibiting the replication of microorganisms (p < 0.05), and decreasing oxidation (p < 0.05) during storage. The incorporation of CLEO into chitosan coating significantly reduced (p < 0.05), TBARS, especially for the Nano-CS- ClEO 2 % and 4 % groups, with values at the end of storage of approximately 0.68 and 1.01 mg MDA/kg respectively. Moreover, the meat treatments with essential oils led to lower carbonyl content production in compared to other groups that treated without essential oils. Coated beef meat had the highest inhibitory effects against microbial growth. The counts of Enterobacteriaceae, lactic acid bacteria (LAB), psychrophilic, and mesophilic bacteria were significantly lower (p < 0.05) in the Nano-CS- ClEO 2 % (1.1, 4.2, 6.2, and 6.32 Log CFU/g, respectively) at day 16. The sensory evaluation indicated that this coating with chitosan nanoemulsions in combination with ClEOs could significantly preserve sensory characteristics of beef meat during storage. Moreover, concerning sensory features, the control samples gained the maximum score. Additionally, the group that contains chitosan in combination with 4 % ClEO nanoliposomes had the highest inhibition of microbial growth, reduced sensory changes, and extending the shelf life of beef meat (p < 0.05). In conclusion, nanoemulsions containing Citrus limon essential oil had a significant preservation effect on beef meat during refrigerated storage by preventing the microorganism's proliferation and decreasing the oxidation of fat and protein (p < 0.05). Therefore, they are suggested to extend the durability of fresh meat products during refrigerated storage.

Chitosan nanoemulsion incorporated with Carum carvi essential oil as ecofriendly alternative for mitigation of aflatoxin B1 contamination in stored herbal raw materials

The present investigation entails the first report on entrapment of Carum carvi essential oil (CCEO) into chitosan polymer matrix for protection of stored herbal raw materials against fungal inhabitation and aflatoxin B1 (AFB1) production. Physico-chemical characterization of nanoencapsulated CCEO was performed through Fourier transform infrared spectroscopy, dynamic light scattering, X-ray diffractometry, and scanning electron microscopy. The nanoencapsulated CCEO displayed improved antifungal and AFB1 suppressing potentiality along with controlled delivery over unencapsulated CCEO. The encapsulated CCEO nanoemulsion obstructed the ergosterol production and escalated the efflux of cellular ions, thereby suggesting plasma membrane as prime target of antifungal action in Aspergillus flavus cells. The impairment in methyglyoxal production and modeling based carvone interaction with Afl-R protein validated the antiaflatoxigenic mechanism of action. In addition, CCEO displayed augmentation in antioxidant potentiality after encapsulation into chitosan nanomatrix. Moreover, the in-situ study demonstrated the effective protection of Withania somnifera root samples (model herbal raw material) against fungal infestation and AFB1 contamination along with prevention of lipid peroxidation. The acceptable organoleptic qualities of W. somnifera root samples and favorable safety profile in mice (animal model) strengthen the application of nanoencapsulated CCEO emulsion as nano-fungitoxicant for preservation of herbal raw materials against fungi and AFB1 mediated biodeterioration.

Evaluation of the in vitro Antileishmanial Activity of Chitosan-Coated Nanoemulsions of Ozonated Olive Oil

ABSTRACT Leishmaniasis is a neglected parasitic disease. Numerous studies suggested that nanoemulsions could improve drug delivery in the treatment of zoonotic cutaneous leishmaniasis. This study aims to determine the effect of chitosan-coated nanoemulsions of ozonated olive oil on Leishmania major promastigote/amastigote in vitro. Nanoemulsions (NEs) were prepared using a sonicator bath at 37 °C for one hour at 1000 W, followed by 24 hours of stirring at pH 5.5. The NE was then supplemented with chitosan and stirred all night long at a low speed. Droplet size, zeta potential, in vitro drug release, and cytotoxicity were examined to optimize the chitosan nanoemulsions (CNE) and chitosan ozonated nanoemulsions (CONE). CONE and CNE were found to have droplet sizes and zeta potentials of 16.86 nm, 19.03 nm, 19.7 mV, and 19.3 mV, respectively. Additionally, the final CONE’s drug loading and encapsulation efficiency were determined to be 100% and 3.21%, respectively. The lower doses of CONE had no cytotoxic effects on macrophages. Additionally, it has the ability to inhibit L. major promastigote/amastigote growth. Therefore, the lower doses of the CONE formulation can inhibit the growth of promastigote and amastigote of L. major in vitro while not being toxic to macrophages.

Sustainable chitosan nanoemulsion coatings/films with agri-food byproducts: advances, composition, production methods and applications in food preservation

Sustainable chitosan nanoemulsion coatings/films with agri-food byproducts: advances, composition, production methods and applications in food preservation

Anti Staphylococcus aureus activity of shikonin @ chitosan nanoemulsion and its effect on the storage quality of pork

Shikonin has been used in food production because of its potent bacteriostatic activity and colorability, but it is limited to be widely used because of its poor water solubility. The aim of this study was to prepare shikonin @ chitosan nanoemulsion (NS) to improve the solubility of shikonin and evaluate its antibacterial activity against Staphylococcus aureus (S. aureus) and the effect on storage quality of a pork food model. The results indicated that NS prepared in this study had a particle size of 147.96 ± 0.28 nm, PDI of 0.259 ± 0.007, and zeta potential of −55.37 ± 0.58 mV, which worked well with water as a solvent energy. NS showed good stability and dispersibility after seven days, and significantly damaged S. aureus appearance and biofilm formation. Food application results showed that NS had better activity against S. aureus and better preservation effect without compromising pork meat quality. At the end of the storage period, pork samples with NS coating showed the lowest values of total viable count (TVC) (7.03 ± 0.06 log CFU/g), pH (7.85 ± 0.01), total volatile basic nitrogen (TVB-N) (8.34 ± 0.50 mg/100 g), thiobarbituric acid reactive substances (TBARS) (7.23 ± 0.47 g/kg). NS showed better biocompatibility in acute toxicity experiments in mice, providing a theoretical basis for its application in food preservation.

Antibacterial activity of juglone @ chitosan nanoemulsion against Staphylococcus aureus and its effect on pork shelf life

Food poisoning caused by Staphylococcus aureus (S. aureus) contaminated meat has received a lot of attention. Although juglone has anti-S. aureus properties, its limited water solubility prevents it from being used in food manufacturing. Juglone @ chitosan nanoemulsion (NJ) was produced for the first time in order to increase its solubility. At the same time, it was applied to the pork model. According to the findings, NJ's particle size was 119.30 nm, its polymer dispersity index (PDI) value was 0.290, and its zeta potential was −57.3 mV. And it's stable over a 7-day storage period. The cell shape and membrane integrity of S. aureus were significantly damaged by NJ. At the same time, NJ showed extreme vigor for biofilm removal. The inclusion of NJ coating significantly reduced S. aureus, total volatile base nitrogen (TVB-N), total viable count (TVC), thiobarbituric acid reactants (TBARS), and pH in the sample when using the pork feeding model. NJ, meantime, halted the sensory evaluation's fall in meat score. Additionally, NJ demonstrated good biocompatibility in mouse acute toxicity tests. The aforementioned findings demonstrate that NJ is anticipated to become an anti-S. aureus and a novel method for coating pork preservation.

Anti-MRSA and Biological Activities of Propolis Concentrations Loaded to Chitosan Nanoemulsion for Pharmaceutics Applications.

Propolis is a naturally occurring substance with beneficial properties; bees produce it from various plant sources, and it is an anti-inflammatory and therapeutic resinous substance. This study aimed to enhance the biological features of propolis extract by loading it onto active film. Firstly, extraction was performed using three solvent systems, and their total phenolic, flavonoid, and antioxidant activity was measured. Propolis ethanol extract (EEP) was evaluated for phenolic fraction content and then chosen to prepare a chitosan-loaded emulsion with several concentrations. The antibacterial, anti-mycotic, and anti-mycotoxigenic properties of the extract and nanoemulsion were assessed. PPE's cytotoxicity and nanoemulsion were evaluated using brine shrimp and cell line assays. Results indicate higher phenolic (322.57 ± 4.28 mg GAE/g DW), flavonoid (257.64 ± 5.27 mg QE/g DW), and antioxidant activity of the EEP. The phenolic fraction is distinguished by 18 phenolic acids with high p-hydroxybenzoic content (171.75 ± 1.64 µg/g) and 12 flavonoid compounds with high pinocembrin and quercetin content (695.91 ± 1.76 and 532.35 ± 1.88 µg/g, respectively). Phenolic acid derivatives (3,4-Dihydroxybenzaldehyde, 3,4-Dihydroxyphenol acetate, and di-methoxy cinnamic) are also found. Concentrations of 50, 100, 150, and 200 ng EEP loaded on chitosan nanoemulsion reflect significant antibacterial activity against pathogenic bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA) and toxigenic fungi, particularly Fusarium. Among the four EEP-loaded concentrations, the nanoemulsion with 150 ng showed outstanding features. Using a simulated medium, 150 and 200 ng of EEP-loaded chitosan nanoemulsion concentrations can stop zearalenone production in Fusarium media with complete fungi inhibition. Also, it reduced aflatoxins production in Aspergillus media, with fungal inhibition (up to 47.18%). These results recommended the EEP-chitosan application for pharmaceutics and medical use as a comprehensive wound healing agent.

Laurus nobilis essential oil nanoemulsion-infused chitosan: A safe and effective antifungal agent for masticatory preservation

The present study reports the first time investigation on encapsulation of Laurus nobilis essential oil into chitosan nanoemulsion (CS-Ne-LNEO) and assessment of its efficacy to inhibit fungal infestation and aflatoxin B1 (AFB1) contamination in stored masticatories food system. Gas chromatography mass spectrometry (GC-MS) analysis revealed m-Eugenol (46.23%) and D-Limonene (8.89%) as the most abundant components of LNEO. The CS-Ne-LNEO was physico-chemically characterized through scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and x-ray diffractometry (XRD) analyses. The CS-Ne-LNEO exhibited broad range of antifungal activity against food contaminating fungi including inhibition of toxigenic Aspergillus flavus (AF-LHP-PE-4) and AFB1 production at lower concentrations as compared to unencapsulated LNEO. The CS-Ne-LNEO caused impairment in ergosterol biosynthesis and enhancement in leakage of Ca2+, Mg2+, K+ ions and 260, 280 nm absorbing materials along with inhibition of methylglyoxal production suggesting the antifungal and antiaflatoxigenic mechanism of action. The DPPH antioxidant activity of CS-Ne-LNEO was noted with IC50 value of 0.004 µL/mL. In addition, the CS-Ne-LNEO caused complete protection of stored Phyllanthus emblica (model masticatories) fruit samples against fungal and AFB1 contamination without altering their sensory characteristics and exhibited high LD50 value (13,504 µL/Kg body weight) mammalian system. Overall, these results indicated that LNEO loaded chitosan nanoemulsion could be promoted as an eco-friendly preservative for complete protection of stored plant masticatories against fungal and AFB1 contamination.

Encapsulation of carvone in chitosan nanoemulsion as edible film for preservation of slice breads against Aspergillus flavus contamination and aflatoxin B1 production

Aspergillus flavus is a common fungus causing bread spoilage by aflatoxin B1 (AFB1) production. Essential oil components are considered as effective antifungal agent; however, volatility and oxidative-instability limited their practical applications. The aim of this study was to fabricate novel chitosan nanoemulsion film incorporating carvone (carvone-Ne) for protection of bread slices against A. flavus and AFB1 contamination in storage conditions. The nanoemulsion was characterized by SEM, DLS, XRD, and FTIR analyses accompanying with sustained delivery of carvone. The carvone-Ne displayed better inhibition of A. flavus (0.5 µL/mL) and AFB1 production (0.4 µL/mL) over unencapsulated carvone along with promising antioxidant activity (p < 0.05). Destruction of ergosterol, mitochondrial-membrane-potential, ions leakage, deformities in methylglyoxal biosynthesis, and in-silico interaction of carvone with Afl-R protein emphasized the antifungal and antiaflatoxigenic mechanisms of action. Further, in-situ preservation potentiality of Carvone-Ne in bread slices with improved gas compositions, and acceptable sensory qualities strengthen its application as innovative packaging material for food preservation.

Angelica archangelica essential oil loaded chitosan nanoemulsion as edible coating for preservation of table grape fruit against Botrytis cinerea contamination and storage quality deterioration

The present study deals with the encapsulation of Angelica archangelica essential oil into chitosan nanoemulsion (AAEO-NE) and evaluation of its effectiveness as novel coating agent with innovative controlled release delivery system for protection of table grape (Vitis vinifera L.) fruit against Botrytis cinerea contamination, and quality deterioration over 30 d of storage (25 ± 2 °C, Relative humidity 85%). The AAEO-NE was characterized through dynamic light scattering (DLS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The mean particle size was tended to increase from 53.69 to 98.63 nm, while ζ-potential was decreased from + 32.3 to + 23.5 mV. Fourier transform infrared spectroscopy (FTIR), and X-ray diffractometry (XRD) analyses suggested intermolecular interaction followed by effective encompassment of AAEO into chitosan nanomatrix. In vitro release study confirmed the biphasic and controlled delivery of AAEO, essentially required for its long term effectiveness in view of maintaining postharvest quality of the treated fruit. The antifungal efficacy of unencapsulated AAEO against B. cinerea was found as 5.5 g L−1, and noticed to be enhanced (2.5 g L−1) after encapsulation into chitosan nanoemulsion. The inhibition of ergosterol biosynthesis followed by subsequent enhancement of ions leakage after treatment of B. cinerea cells with AAEO-NE suggested plasma membrane as major site of antifungal activity. During in vivo investigation, AAEO-NE coating inhibited the contamination of B. cinerea and maintained the quality attributes like weight, titrable acidity, total soluble solids, phenolic content, and pH of table grape fruit. Additionally, the preservation of enzymatic antioxidants, reduced respiration rate, and better sensory qualities of coated table grape fruit recommend the functional potentiality of chitosan as biocompatible wall matrix to encapsulate AAEO and application as novel nano-green smart coating based fungitoxicant and shelf-life enhancer in fruit and agricultural industries.

Enhancement of Shelf Life of Guava Fruits by Application of Chitosan based Nanoemulsion

Background: Edible coating is an effective and widely used approach for preservation of quality of fruits. The physiological changes remain intact with edible coating that leads to maintain the nutritional quality. The current study is an endeavor to develop an appropriate edible coating material that may be applied over fruits as freshness indicators. Methods: Chitosan nanoemulsion was prepared with ultrasonication and guava samples were dipped in prepared nanoemulsion. Quality evaluation of guava samples was evaluated during 15 day storage in triplicates. Result: Guava fruits were coated with chitosan based emulsion to preserve its nutritional qualities. Weight loss, TSS, acidity (%), ascorbic acid and 2,2 diphenyl-1-picrylhydrazyl (DPPH) inhibition activity were measured in coated and control guava samples. Samples coated with guava were found to preserve overall quality. TSS and acidity content, which is ripening indicator, was found to be not affected significantly in coated sample whereas in control samples TSS increased and acidity decreased during storage. The changes in weight loss were significantly more in control samples than coated samples. Ascorbic acid and antioxidant activity variation was observed more in control samples.

The Antimicrobial Efficacy of Chitosan Nanoemulsion Coating Incorporating Ziziphora Clinopodioide Essential Oil and Nisin against Listeria Monocytogenes Inoculated in Vacuum-Packed Chicken Breast Fillet

The Antimicrobial Efficacy of Chitosan Nanoemulsion Coating Incorporating Ziziphora Clinopodioide Essential Oil and Nisin against Listeria Monocytogenes Inoculated in Vacuum-Packed Chicken Breast Fillet

Enhancing the Antioxidant, Antibacterial, and Wound Healing Effects of Melaleuca alternifolia Oil by Microencapsulating It in Chitosan-Sodium Alginate Microspheres

In this study, antibacterial and antioxidant molecules-rich Melaleuca alternifolia oil (tea tree oil (TTO)) loaded chitosan (CS) based nanoemulsions (NEMs) were prepared and encapsulated by sodium alginate (SA) microsphere for antibacterial wound dressing. CS-TTO NEMs were prepared by oil-in-water emulsion technique, and the nanoparticle tracking analysis (NTA) confirmed that the CS-TTO NEMs had an average particle size of 89.5 nm. Further, the SA-CS-TTO microsphere was confirmed through SEM analysis with an average particle size of 0.76 ± 0.10 µm. The existence of TTO in CS NEMs and SA encapsulation was evidenced through FTIR analysis. The XRD spectrum proved the load of TTO and SA encapsulation with CS significantly decreased the crystalline properties of the CS-TTO and SA-CS-TTO microsphere. The stability of TTO was increased by the copolymer complex, as confirmed through thermal gravimetric analysis (TGA). Furthermore, TTO was released from the CS-SA complex in a sustained manner and significantly inhibited the bacterial pathogens observed under confocal laser scanning microscopy (CLSM). In addition, CS-TTO (100 µg/mL) showed antioxidant potential (>80%), thereby increasing the DPPH and ABTS free radicals scavenging ability of SA-CS-TTO microspheres. Moreover, CS and SA-CS-TTO microsphere exhibited negligible cytotoxicity and augmented the NIH3T3 cell proliferation confirmed in the in vitro scratch assay. This study concluded that the SA-CS-TTO microsphere could be an antibacterial and antioxidant wound dressing.

Encapsulation of Cymbopogon khasiana × Cymbopogon pendulus Essential Oil (CKP-25) in Chitosan Nanoemulsion as a Green and Novel Strategy for Mitigation of Fungal Association and Aflatoxin B1 Contamination in Food System.

The present study deals with the encapsulation of Cymbopogon khasiana × Cymbopogon pendulus essential oil (CKP-25-EO) into a chitosan nanoemulsion and efficacy assessment for inhibition of fungal inhabitation and aflatoxin B1 (AFB1) contamination in Syzygium cumini seeds with emphasis on cellular and molecular mechanism of action. DLS, AFM, SEM, FTIR, and XRD analyses revealed the encapsulation of CKP-25-EO in chitosan with controlled delivery. The CKP-25-Ne displayed enhanced antifungal (0.08 µL/mL), antiaflatoxigenic (0.07 µL/mL), and antioxidant activities (IC50 DPPH = 6.94 µL/mL, IC50 ABTS = 5.40 µL/mL) in comparison to the free EO. Impediment in cellular ergosterol, methylglyoxal biosynthesis, and in silico molecular modeling of CKP-25-Ne validated the cellular and molecular mechanism of antifungal and antiaflatoxigenic activity. The CKP-25-Ne showed in situ efficacy for inhibition of lipid peroxidation and AFB1 secretion in stored S. cumini seeds without altering the sensory profile. Moreover, the higher mammalian safety profile strengthens the application of CKP-25-Ne as a safe green nano-preservative against fungal association, and hazardous AFB1 contamination in food, agriculture, and pharmaceutical industries.

Chitosan based encapsulation of Valeriana officinalis essential oil as edible coating for inhibition of fungi and aflatoxin B1 contamination, nutritional quality improvement, and shelf life extension of Citrus sinensis fruits

In this study, a novel chitosan nanoemulsion coating embedded with Valeriana officinalis essential oil (Ne-VOEO) was synthesized in order to improve the postharvest quality of Citrus sinensis fruits against infesting fungi, and aflatoxin B1 (AFB1) mediated nutritional deterioration. The developed nanoemulsion was characterized through SEM, FTIR, XRD, and DLS analyses. The nanoemulsion showed controlled delivery of VOEO responsible for effective inhibition of Aspergillus flavus, A. niger, A. versicolor, Penicillium italicum, and Fusarium oxysporum growth at 6.5, 5.0, 4.0, 5.5, and 3.5 μL/mL, respectively and AFB1 production at 5.0 μL/mL. The biochemical and molecular mechanism of aflatoxigenic A. flavus inhibition, and AFB1 diminution was associated with impairment in ergosterol biosynthesis, methylglyoxal production, and stereo-spatial binding of valerianol in the cavity of Ver-1 protein. During in vivo investigation, Ne-VOEO coating potentially restrained the weight loss, and respiratory rate of C. sinensis fruits with delayed degradation of soluble solids, titrable acidity, pH, and phenolic contents along with maintenance of SOD, CAT, APX activities (p < 0.05) and sensory attributes under specific storage conditions. Based on overall findings, Ne-VOEO nanoemulsion could be recommended as green, and smart antifungal coating agent in prolonging the shelf-life of stored fruits with enhanced AFB1 mitigation.

Optimization of thiamine chitosan nanoemulsion production using sonication treatment

The production of thiamine chitosan nanoemulsion via sonication treatment has been optimized using response surface methodology (RSM). This study examines the effect of sonication treatment on thiamine chitosan formulation and variations in time, amplitude, and surfactant concentration to distinguish optimum production conditions. Chitosan thiamine nanoemulsion was prepared using the central composite design (CCD) with 3 independent variables (time, amplitude, and surfactant concentration), which generated 20 experimental points. The optimum condition was determined by analyzing the response variable, which, in this study, is viscosity. The analysis was carried out using the Minitab 18 software. The sample as formulated using the optimum conditions derived were then tested for particle size using a Particle Size Analyzer (PSA). The results showed that the 3-factorial design and response surface methodology could determine the optimum conditions for the formulation process of chitosan thiamine nanoemulsion. The optimum viscosity of the thiamine chitosan nanoemulsion determined was 10.5 mPa s which was obtained with 55.2 min sonication time, Tween 80 surfactant concentration of 3.4%, and amplitude of 56.8 m. The chitosan thiamine nanoemulsion produced with these conditions had a particle size of 20.1 nm and a polydispersity index of 0.446, which indicated that it was stable and homogeneous.

Changes in selenium-enriched chicken sausage containing chitosan nanoemulsion and quality changes in the nanoemulsion during storage

A novel food-processing technology of selenium (Se)-enriched chicken sausage has been developed. The process consists of two different concentrations (250 mg/kg and 500 mg/kg) of chitosan nanoemulsions, which are added to Se-enriched chicken sausage to significantly reduce the pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) (P < 0.05) during storage. This approach is known to reduce the quality deterioration in Se-enriched chicken sausage. In addition, the chitosan content of 250 mg/kg in the nanoemulsion affected the odor and unsaturated fatty acid content of chicken sausages. Partial least squares discriminant analysis (PLS-DA) revealed cyclotrisiloxane as the key to distinguish the treatment group from the control group. In addition, the chitosan nanoemulsion effectively inhibited the growth of common spoilage bacteria of chicken sausages. In all, the chitosan nanoemulsion decreased the spoilage rate in chicken sausage and reduced bacteria spoilage, indicating its potential as a new food additive.

Preparation and characterization of a novel nanoemulsion consisting of chitosan and Cinnamomum tamala essential oil and its effect on shelf-life lengthening of stored millets

This study aimed to improve the stability of Cinnamomum tamala essential oil (CTEO) via encapsulating into chitosan nanoemulsion (CsNe) through an ionic-gelation technique and explore its food preservative efficacy against aflatoxigenic strain of Aspergillus flavus (AFLHPSi-1, isolated from stored millet), aflatoxin B1 (AFB1) contamination, and lipid peroxidation, causing qualitative deterioration of stored millets. The CTEO was characterized through gas chromatography–mass spectrometry (GC–MS) analysis that confirmed the presence of linalool as a major component occupying approximately 82.64% of the total oil. The synthesized nanoparticles were characterized through scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analysis. The encapsulation efficiency (EE) and loading capacity (LC) of CTEO-CsNe were found to be 97.71% and 3.33%, respectively. In vitro release study showed a biphasic release pattern: with an initial burst release followed by a controlled release of CTEO. During investigation of efficacy, the CTEO-CsNe caused complete inhibition of A. flavus growth, and AFB1 biosynthesis at 1.0 and 0.8 μL/mL, respectively. The CTEO-CsNe exhibited its antifungal mode of action by altering fungal plasma membrane integrity (ergosterol inhibition) and permeability (leakage of important cellular constituents), and antiaflatoxigenic mode of action by inhibiting cellular methylglyoxal biosynthesis. CTEO-CsNe showed high free radical scavenging capacity (IC50 = 5.08 and 2.56 μL/mL) against DPPH•+ and ABTS•+ radicals, respectively. In addition, CTEO-CsNe presented remarkable preservative efficacy, inhibiting AFB1 and lipid peroxidation in model food system (Setaria italica) without altering their organoleptic properties. Based on overall results, CTEO-CsNe can be recommended as a novel shelf-life enhancer of stored millet samples.

Chitosan encompassed Aniba rosaeodora essential oil as innovative green candidate for antifungal and antiaflatoxigenic activity in millets with emphasis on cellular and its mode of action.

The present study demonstrates first time investigation on encapsulation of Aniba rosaeodora essential oil into chitosan nanoemulsion (AREO-CsNe) with the aim of improvement of its antifungal, and aflatoxin B1 (AFB1) inhibitory performance in real food system. The GC–MS analysis of AREO revealed the presence of linalool (81.46%) as a major component. The successful encapsulation of EO into CsNe was confirmed through SEM, FTIR, and XRD analysis. The in-vitro release study showed the controlled release of AREO. AREO-CsNe caused complete inhibition of Aspergillus flavus (AFLHPSi-1) growth and AFB1 production at 0.8 and 0.6 μl/ml, respectively, which was far better than AREO (1.4 and 1.2 μl/ml, respectively). Impairment of ergosterol biosynthesis coupled with enhancement of cellular materials leakage confirmed plasma membrane as the possible antifungal target of both AREO and AREO-CsNe. Significant inhibition of methylglyoxal (AFB1 inducer) synthesis in AFLHPSi-1 cells by AREO and AREO-CsNe confirmed their novel antiaflatoxigenic mode of action. In-silico molecular docking studies revealed effective interaction of linalool with Ver-1 and Omt-A proteins, leading to inhibition of AFB1 biosynthesis. Further, AREO-CsNe showed enhanced antioxidant activity with IC50 values 3.792 and 1.706 μl/ml against DPPH• and ABTS•+ radicals, respectively. In addition, AREO-CsNe caused 100% protection of stored millets (Setaria italica seeds) from AFB1 contamination and lipid peroxidation over a period of 1 year without compromising its sensory properties and exhibited high safety profile with LD50 value 9538.742 μl/kg body weight. Based on enhanced performance of AREO-CsNe over AREO, it can be recommended as a novel substitute of synthetic preservative for preservation of stored millets.