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.

Encapsulation of Apium graveolens essential oil into chitosan nanobiopolymer for protection of stored rice against Fusarium verticillioides and fumonisins contamination.

The present investigation entails the encapsulation of Apium graveolens essential oil into chitosan nanobiopolymer (AGEO-Ne) and assessment of its efficacy against Fusarium verticillioides contamination and fumonisins biosynthesis in stored rice (Oryza sativa L.) samples. The AGEO was encapsulated through ionic gelation process and characterized by scanning electron microscopy (SEM), Dynamic light scattering (DLS), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The AGEO exhibited bi-phasic delivery pattern from chitosan matrix. The AGEO caused complete inhibition of F. verticillioides growth at 1.2 µL/mL, while fumonisin B1 (FB1) and B2 (FB2) biosynthesis at 1.2 and 1.0 µL/mL, respectively. On the other hand, nanoencapsulated AGEO (AGEO-Ne) exhibited improved efficacy, caused complete inhibition of fungal growth at 0.8 µL/mL, and FB1 and FB2 production at 0.8 and 0.6 µL/mL, respectively. AGEO-Ne caused 100 % inhibition of ergosterol synthesis at 0.8 µL/mL and exhibited greater efflux of Ca2+, Mg2+, K+ ions (18.99, 21.63, and 25.38 mg/L) as well as 260 and 280 nm absorbing materials from exposed fungal cells. The in silico interaction of granyl acetate and linalyl acetate with FUM 21 protein validated the molecular mechanism for inhibition of FB1 and FB2 biosynthesis. Further, improvement in antioxidant activity of AGEO-Ne was observed after encapsulation with IC50 values of 12.08 and 6.40 µL/mL against DPPH and ABTS radicals, respectively. During in situ investigation, AGEO caused 82.09 and 86.32 % protection of rice against F. verticillioides contamination in inoculated and uninoculated rice samples, respectively, while AGEO-Ne exhibited 100 % protection of fumigated rice samples against F. verticillioides proliferation as well as FB1 and FB2 contamination. The AGEO-Ne also caused better retardation of lipid peroxidation (41.35 and 37.52 µM/g FW malondialdehyde in inoculated and uninoculated treatment) and acceptable organoleptic properties in rice samples, which strengthen its application as plant based novel preservative in food and agricultural 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.

Green facile synthesis of cajuput (Melaleuca cajuputi Powell.) essential oil loaded chitosan film and evaluation of its effectiveness on shelf-life extension of white button mushroom.

This study reports first time investigation on efficacy of cajuput essential oil loaded chitosan nanoparticle (CjEO-CSNP) on shelf-life of white button mushroom (Agaricus bisporus) stored at 4±1 °C for 7-days. CjEO-CSNP was characterized through scanning electron microscopy, X-ray diffraction, and dynamic light scattering. The nanoparticles exhibited spherical shapes with average particle size 43.17-97.03 nm. The nanoencapsulation efficiency and loading capacity were ranged between 45.86 and 92.26% and 0.69-8.87%, respectively. The release study confirmed that CjEO-CSNP showed biphasic release patterns at different pH. Positive results were unveiled when the effect of CjEO-CSNP on shelf-life of mushroom was validated by analyzing the visual appearance and firmness. Further, CjEO-CSNP prevented weight loss and respiration rate, and improved the antioxidant activity of mushrooms. CjEO-CSNP also exhibited high safety profile (LD50= > 1200 mg/Kg body weight) without altering the sensory quality of coated mushrooms. Overall, CjEO-CSNP might be used as promising candidate to lengthen the shelf-life of button mushroom.

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.

Mechanistic investigations on antifungal and antiaflatoxigenic activities of chemically characterised Carum carvi L. essential oil against fungal infestation and aflatoxin contamination of herbal raw materials.

This study aimed to investigate the efficiency of chemically characterised Carum carvi essential oil (CcEO) against aflatoxin B1 (AFB1) producing strain of Aspergillus flavus (AF-LHP-WS-4) causing deterioration of herbal raw materials (HRM). GC-MS analysis of the EO revealed the presence of carvone (69.85%) as a dominant component. CcEO caused complete suppression of A. flavus growth and AFB1 secretion at 0.7 and 0.6 µL/mL, respectively. The investigation on antifungal mode of action showed that CcEO inhibited fungal growth via abrogating ergosterol biosynthesis and triggered efflux of vital cellular ions. The inhibition of AFB1 biosynthesis was attributed to the inhibition of cellular methylglyoxal (MG) biosynthesis. In addition, CcEO showed remarkable antioxidant activity (IC50 = 10.564 µL/mL) against DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals. Based on overall results, it can be concluded that the CcEO may be recommended as potential antifungal agent for protection of HRM from fungal infestation and AFB1 contamination.

Assessing the Levisticum officinale Koch. essential oil as a novel preservative for stored chia seeds (Salvia hispanica L.) with emphasis on probable mechanism of action.

The present study was undertaken to explore the inhibitory effect of Levisticum officinale Koch. essential oil (LoffEO) on the growth and aflatoxin B1 secretion by Aspergillus flavus (AF-LHP-SH1, aflatoxigenic strain) causing deterioration of stored chia seeds (Salvia hispanica). The chemical profile analysis of LoffEO by GC-MS analysis revealed the presence of α-terpinyl acetate (26.03 %) as a major component followed by terpineol <1- > (24.03 %) and citronellal (24.03 %). Results on antifungal and antiaflatoxigenic activity indicated that LoffEO at 2.0 and 1.75 µL/mL caused complete inhibition of growth and aflatoxin B1 production, respectively. Antifungal toxicity of LoffEO was strongly correlated with the inhibition of ergosterol content, leakage of cellular ions, and disintegration of membrane permeability. Reduction in cellular methylglyoxal by LoffEO indicated a novel antiaflatoxigenic mechanism of action. The LoffEO showed moderate free radical quenching activity in DPPH assay (IC50 = 26.10 µL/mL) and exhibited remarkable inhibitory efficacy against lipid peroxidation of chia seeds. In addition, LoffEO presented strong in situ antiaflatoxigenic efficacy, and exhibited non-phytotoxic nature, acceptable sensory characteristics, and favorable safety profile (LD50 = 19786.59 µL/kg), which recommends its practical utilization as a novel and safe preservative to improve the shelf life of stored chia seeds from fungal infestation and aflatoxin B1 contamination.

Essential oils and their bioactive compounds as eco-friendly novel green pesticides for management of storage insect pests: prospects and retrospects.

The control of storage insect pests is largely based on synthetic pesticides. However, due to fast growing resistance in the targeted insects, negative impact on humans and non-target organisms as well as the environment, there is an urgent need to search some safer alternatives of these xenobiotics. Many essential oils (EOs) and their bioactive compounds have received particular attention for application as botanical pesticides, since they exhibited high insecticidal efficacy, diverse mode of action, and favourable safety profiles on mammalian system as well as to the non-target organisms. Data collected from scientific articles show that these EOs and their bioactive compounds exhibited insecticidal activity via fumigant, contact, repellent, antifeedant, ovicidal, oviposition deterrent and larvicidal activity, and by inhibiting/altering important neurotransmitters such as acetylcholine esterase (AChE) and octopamine or neurotransmitter inhibitor γ-amino butyric acid (GABA), as well as by altering the enzymatic [superoxide dismutase (SOD), catalase (CAT), peroxidases (POx), glutathione-S-transferase (GST) and glutathione reductase (GR)] and non-enzymatic [glutathione (GSH)] antioxidant defence systems. However, in spite of promising pesticidal efficacy against storage pests, the practical application of EOs and their bioactive compounds in real food systems remain rather limited because of their high volatility, poor water solubility and susceptibility towards degradation. Nanoencapsulation/nanoemulsion of EOs is currently considered as a promising tool that improved water solubility, enhanced bio-efficacy, stability and controlled release, thereby expanding their applicability.

Assessment of nanoencapsulated Cananga odorata essential oil in chitosan nanopolymer as a green approach to boost the antifungal, antioxidant and in situ efficacy.

In this study, a comparative efficacy of Cananga odorata EO (CoEO) and its nanoencapsulated formulation into chitosan nanoemulsion (CoEO-CsNe) against a toxigenic strain of Aspergillus flavus (AF-M-K5) were investigated for the first time in order to determine its efficacy in preservation of stored food from fungal, aflatoxin B1 (AFB1) contamination and lipid peroxidation. GC and GC-MS analysis of CoEO revealed the presence of linalool (24.56%) and benzyl acetate (22.43%) as the major components. CoEO was encapsulated into chitosan nanoemulsion (CsNe) through ionic-gelation technique and characterized by High Resolution-Scanning Electron Microscopy (HR-SEM), Fourier Transform Infrared spectroscopy (FTIR), and X-Ray Diffraction (XRD) analysis. The CoEO-CsNe during in vitro investigation against A. flavus completely inhibited the growth and AFB1 production at 1.0 µL/mL and 0.75 µL/mL, respectively. Additionally, CoEO-CsNe showed improved antioxidant activity against DPPH• and ABTS•+ with IC50 value 0.93 and 0.72 µL/mL, respectively. Further, CoEO-CsNe suppressed fungal growth, AFB1 secretion and lipid peroxidation in Arachis hypogea L. during in situ investigation without causing any adverse effect on seed germination. Overall results demonstrated that the CoEO-CsNe has potential of being utilized as a suitable plant based antifungal agent to improve the shelf-life of stored food against AFB1 and lipid peroxidation mediated biodeterioration.

Zingiber zerumbet L. essential oil-based chitosan nanoemulsion as an efficient green preservative against fungi and aflatoxin B1 contamination.

The present study envisages the potential application of chitosan-coated Zingiber zerumbet essential oil nanoemulsion (ZEO-CsNE) as green antimicrobial preservative against Aspergillus flavus, aflatoxin B1 (AFB1 ), and lipid peroxidation of stored functional foods. GC-MS analysis of ZEO exhibited the abundance of cis-geraniol (15.53%) as the major component. ZEO-CsNE showed biphasic release profile during in vitro release study conducted for 10 days. The ZEO-CsNE inhibited the growth of A. flavus (strain AF-LHP-SH1) and AFB1 production at 1.0 and 0.8 µL/mL, respectively. Interestingly, considerable reduction in ergosterol biosynthesis followed by enhanced leakage of vital cellular contents and methylglyoxal inhibition represents novel antifungal and antiaflatoxigenic mechanism of action, respectively. Further, ZEO-CsNE inhibited lipid peroxidation and AFB1 production in postharvest Salvia hispanica seeds during in situ trial and presented favorable safety profile (median lethal dose [LD50 ] = 29,114 µL/kg) for male mice. Based on overall observations, ZEO-CsNE could be recommended as a green antimicrobial substitute of synthetic preservatives for in vitro and in situ protection of functional food samples. PRACTICAL APPLICATION: Food industries are facing enormous amount of burden coming from fungal and aflatoxin contamination that can cause severe adverse effects to humans. Essential oils (EOs) are well known for their food preservative efficacy; however, some limitations such as oxidative instability in open system may limit their application directly into food system. The encapsulation of the EOs into polymeric matrix could provide a barrier that will protect the EOs from degradation. This research could provide a basis for utilization of EO after encapsulation into chitosan nanoemulsion for industrial-scale application for preservation of stored functional foods from fungal and aflatoxin contamination.

Nanoencapsulated Monarda citriodora Cerv. ex Lag. essential oil as potential antifungal and antiaflatoxigenic agent against deterioration of stored functional foods.

In vitro antifungal activity of the essential oil from Monarda citriodora (MCEO) with possible mode of action was evaluated against A. flavus (AF-LHP-SH1) and 15 other storage molds for controlling postharvest deterioration of stored functional food samples. The chemical profiling of MCEO as done through GC-MS analysis revealed caryophyllene (19.15%) as the major component. The MCEO showed broad spectrum fungitoxicity and completely inhibited the growth of all tested molds and aflatoxin B1 (AFB1) production by AF-LHP-SH1 at 1.40 and 1.20 µL/mL, respectively. Plasma membrane damage and methylglyoxal inhibition was confirmed as the possible antifungal and antiaflatoxigenic mode of action of MCEO. MCEO exhibited remarkable antioxidant activity with IC50 value 2.24 µL/mL as determined through DPPH assay and did not cause adverse effect on seed germination. In addition, the MCEO was encapsulated into chitosan nanoparticle, characterized (SEM, FTIR, XRD) and assessed for their potential against inhibition of growth and AFB1 production. MCEO after encapsulation exhibited enhanced efficacy inhibiting fungal growth and AFB1 production by AF-LHP-SH1 at 0.6 and 0.5 µL/mL, respectively. Encapsulated MCEO may be recommended as novel preservative to extend the shelf life of stored functional food samples.

Improvement of in vitro and in situ antifungal, AFB1 inhibitory and antioxidant activity of Origanum majorana L. essential oil through nanoemulsion and recommending as novel food preservative.

Origanum majorana essential oil (OmEO) encapsulated into chitosan nanoemulsion is being reported as a novel preservative of stored food items against fungi, aflatoxin B1 (AFB1) contamination and lipid peroxidation. The major component of OmEO identified through GC-MS was terpinen-4-ol (28.92%). HR-SEM, FTIR and XRD analyses confirmed successful encapsulation of OmEO into chitosan nanoemulsion (OmEO-CsNe). The results showed remarkable improvement in efficacy after nanoencapsulation, since OmEO-CsNe completely inhibited the growth and AFB1 production by Aspergillus flavus at 1.0 µL/mL, which was 2.5 and 1.5 µL/mL, respectively for OmEO. The inhibition of ergosterol followed by release of cellular ions and 260 and 280 nm absorbing materials demonstrated plasma membrane as possible antifungal target. Inhibition of methylglyoxal confirmed antiaflatoxigenic mode of action. OmEO-CsNe showed enhanced antioxidant activity (IC50 = 14.94 and 5.53 µL/mL for DPPH and ABTS, respectively) and caused in situ inhibition of lipid peroxidation and AFB1 production in maize (third most important staple crop after wheat and rice) without altering their sensory attributes and presented safety profile (LD50 = 11,889 µL/kg) when tested on mice. The findings indicate that the encapsulation considerably enhances the performance of OmEO, therefore can be recommended as a promising antifungal agent to extend the shelf-life of food items.

Assessment of preservative potential of Bunium persicum (Boiss) essential oil against fungal and aflatoxin contamination of stored masticatories and improvement in efficacy through encapsulation into chitosan nanomatrix.

The study reports the preservative efficacy of Bunium persicum (Boiss) essential oil (BPEO) against fungal and aflatoxin B1 (AFB1) contamination of stored masticatories and boosting of its efficacy through encapsulation into chitosan. BPEO was chemically characterized through GC-MS analysis, which revealed γ-terpinene as the major compound. The BPEO at 1.2 µL/mL concentration completely inhibited the growth of toxigenic strain of Aspergillus flavus (AF-LHP-PE-4) along with 15 common food borne moulds and AFB1 secretion. The BPEO exerts its antifungal action on plasma membrane, as confirmed through ergosterol inhibition, alteration of membrane fluidity and enhancement of cellular ions and 260 and 280 nm absorbing material leakage. The antiaflatoxigenic mechanism of action of BPEO was confirmed through methylglyoxal reduction. Further, BPEO showed strong antioxidant activity (IC50 = 7.36 µL/mL) as measured by DPPH· assay. During in situ investigation, BPEO completely inhibited AFB1 production in model food (Phyllanthus emblica) system without altering the sensory properties and also exhibited high LD50 value (14,584.54 µL/kg) on mice. In addition, BPEO was encapsulated into chitosan, characterized and tested for their potential to inhibit growth and AFB1 production. The mean particle size, PDI and zeta potential of formed BPEO-loaded chitosan nanoparticle (CS-Np-BPEO) were performed to confirm successful encapsulation. The result revealed nanoencapsulated BPEO showed enhanced activity and completely inhibited the growth and AFB1 production by AF-LHP-PE-4 at 0.8 µL/mL. Based on findings, it could be concluded that the BPEO and its encapsulated formulation can be recommended as a potential plant-based preservative against fungal and aflatoxin contamination of stored masticatories.

Chemically characterised Pimenta dioica (L.) Merr. essential oil as a novel plant based antimicrobial against fungal and aflatoxin B1 contamination of stored maize and its possible mode of action.

The chemical characterisation of Pimenta dioica essential oil (PDEO) revealed the presence of 50 components, amongst which α-Terpineol (30.31%) was the major component followed by ß-Linalool (6.75%) and γ-Terpinene (4.64%). The oil completely inhibited the growth of aflatoxin B1 secreting strain Aspergillus flavus LHP-VS-8 and aflatoxin B1 production at 2.5 µL/mL and 1.5 µL/mL, respectively. The oil caused dose dependent reduction of methylglyoxal (an AFB1 inducer), enhanced leakage of Ca2+, Mg2+ and K+ ions and significantly reduced ergosterol content of fungal plasma membrane. During in situ experiments, PDEO exhibited complete protection of fumigated maize cob slices from fungal infestation without affecting seed germination. The chemically characterised PDEO is recommended as a plant based preservative and shelf life enhancer of food commodities by preventing fungal growth, AFB1 production and lipid peroxidation. This is the first report on PDEO as inhibitor of AFB1 secretion and methylglyoxal biosynthesis.

Fabrication, characterization and practical efficacy of Myristica fragrans essential oil nanoemulsion delivery system against postharvest biodeterioration.

The present study deals with encapsulation of Myristica fragrans essential oil (MFEO) into chitosan nano-matrix, their characterization and assessment of antimicrobial activity, aflatoxin inhibitory potential, safety profiling and in situ efficacy in stored rice as environment friendly effective preservative to control the postharvest losses of food commodities under storage. Surface morphology of MFEO-chitosan nanoemulsion as well as encapsulation of MFEO was confirmed through SEM, FTIR and XRD analysis. In vitro release characteristics with biphasic burst explained controlled volatilization from nanoencapsulated MFEO. Unencapsulated MFEO exhibited fungitoxicity against 15 food borne molds and inhibited aflatoxin B1 secretion by toxigenic Aspergillus flavus LHP R14 strain. In contrast, nanoencapsulated MFEO showed better fungitoxicity and inhibitory effect on aflatoxin biosynthesis at lower doses. In situ efficacy of unencapsulated and nanoencapsulated MFEO on stored rice seeds exhibited effective protection against fungal infestation, aflatoxin B1 contamination, and lipid peroxidation. Both the unencapsulated and nanoencapsulated MFEO did not affect the germination of stored rice seeds confirming non-phytotoxic nature. In addition, negligible mammalian toxicity of unencapsulated MFEO (LD50 = 14,289.32 µL/kg body weight) and MFEO loaded chitosan nanoemulsion (LD50 = 9231.89 µL/kg body weight) as revealed through favorable safety profile recommend the industrial significance of nanoencapsulated MFEO as an effective green alternative to environmentally hazardous synthetic pesticides for protection of food commodities during storage.

Antimicrobial activity, antiaflatoxigenic potential and in situ efficacy of novel formulation comprising of Apium graveolens essential oil and its major component.

The present study reports the formulation of Apium graveolens essential oil (AGEO) with its major components linalyl acetate (LA) and geranyl acetate (GA) (1:1:1) as a novel green preservative for protection of postharvest food commodities from fungal infestations, aflatoxin B1 (AFB1) secretion, free radical generation and lipid peroxidation. The essential oil based novel formulation displayed considerable inhibitory action against fourteen food borne molds responsible for deterioration of stored food commodities, in addition to the most toxigenic strain of Aspergillus flavus (AFLHPR14) isolated from fungal and aflatoxin contaminated rice seeds. The observed higher efficacy of designed formulation was due to the synergistic action of essential oil and its major components. Fungal plasma membrane was recorded as the possible target site of antifungal action of the formulation as revealed through reduction in membrane ergosterol content, increased intracellular propidium iodide (PI) fluorescence and enhanced leakage of cellular ions (sodium, potassium, calcium) and 260, 280 nm absorbing materials. Further, inhibition of methylglyoxal (an aflatoxin inducer) confirmed the aflatoxin inhibitory potential of novel formulation based on essential oil and its major components. High antioxidant potential as observed through DPPH and ABTS·+ radical scavenging assay, improved phenolic content, considerable inhibition of lipid peroxidation in stored rice seeds, in situ efficacy on AFB1 inhibition in food system under storage container system, acceptable sensorial characteristics and favorable safety profile during animal trials suggest the recommendation of the designed formulation for large scale application as green preservative by food and agriculture based industries against fungal and aflatoxin contamination of stored commodities.

Encapsulation in chitosan-based nanomatrix as an efficient green technology to boost the antimicrobial, antioxidant and in situ efficacy of Coriandrum sativum essential oil.

The present investigation deals with first time report on encapsulation of Coriandrum sativum essential oil (CSEO) in chitosan nanomatrix as a green nanotechnology for enhancing its antimicrobial, aflatoxin inhibitory and antioxidant efficacy. Chitosan nano biopolymer entrapped CSEO as prepared through ionic gelation process showed broad spectrum fungitoxicity against molds infesting stored rice and also exhibited enhanced bioefficacy than unencapsulated CSEO. The CSEO entrapped in chitosan nanomatrix lead to decrement in important fungal membrane biomolecule i.e. ergosterol and leakage of UV-absorbing substances along with vital cellular ions. The CSEO encapsulation in selected biopolymer nanomatrix effectively checked methylglyoxal (the aflatoxin inducer) biosynthesis, confirming antiaflatoxigenic mode of action. The physico-chemical properties, considerable decrease in lipid peroxidation and improved in situ AFB1 suppressive as well as antifungal potential of CSEO nanocapsules suggested the deployment of chitosan based nano biopolymer for encapsulation of essential oils as an ecofriendly technology for application in food industries in order to enhance the shelf life and control the fungal and aflatoxin contamination of stored rice.

Assessment of Melissa officinalis L. essential oil as an eco-friendly approach against biodeterioration of wheat flour caused by Tribolium castaneum Herbst.

The study reports efficacy of Melissa officinalis L. essential oil (MOEO) as a safe plant-based insecticide against Tribolium castaneum Herbst (TC) by induction of oxidative stress. MOEO nanoencapsulation in chitosan matrix was performed to enhance its bioefficacy. GC-MS analysis of MOEO depicted geranial (31.54%), neral (31.08%), and ß-caryophyllene (12.42%) as the major components. MOEO showed excellent insecticidal potential in contact (100% mortality at 0.157 µL/cm2) and fumigant bioassays (LC50 = 0.071 µL/mL air) and 100% repellency at concentration ≤ 0.028 µL/cm2. Increased reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and decreased ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) at the LC50 dose suggested significant oxidative stress on TC in MOEO treatment sets. The encapsulated MOEO exhibited enhanced activity as fumigant (LC50 = 0.048 µL/mL air) and showed significant antifeedant activity in situ (EC50 = 0.043 µL/mL). High LD50 value (13,956.87 µL/kg body weight of mice) confirmed favorable toxicological profile for non-target mammals. The findings depict potential of nanoencapsulated MOEO as an eco-friendly green pesticide against infestation of stored food by TC.