Browsing by Author "Deepika"

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Antifungal, Antiaflatoxin and Antioxidant Activity of Plant Essential Oils and Their In Vivo Efficacy in Protection of Chickpea Seeds
(Blackwell Publishing Ltd, 2016) Bhanu Prakash; Akash Kedia; Aakanksha Singh; Shashi Yadav; Arti Singh; Amrita Yadav; Deepika; Nawal Kishore Dubey
This study presents the efficacy of six essential oils (EOs), viz. Carum carvi, Myristica fragrans, Melaleuca leucadendra, Cinnamomum camphora, Pelargonium odoratissimum and Cymbopogon citratus, as food preservatives based on antifungal, antiaflatoxin and antioxidant activity. The minimum inhibitory concentration of EOs against aflatoxigenic strain of Aspergillus flavus (LHP-10) and 13 other storage molds ranged between 1.25 and 6.0μL/mL, while aflatoxin inhibition was observed at 1.0-5.0μL/mL. EOs also exhibited free-radical scavenging activity through DPPH (2,2-diphenyl-1-picrylhydrazil) assay as IC50 value ranged between 3.96 and 96.63μL/mL. The antifungal action of EOs was observed in terms of reduction in ergosterol content of the plasma membrane of A.flavus. The EOs provided >50% protection of chickpea samples against fungal association without affecting their germination during in vivo testing in storage containers. Based on antifungal, antiaflatoxigenic, antioxidant potential and in vivo efficacy, the tested EOs may be recommended as plant-based food preservatives. © 2016 Wiley Periodicals, Inc.
Antimicrobial activity, antiaflatoxigenic potential and in situ efficacy of novel formulation comprising of Apium graveolens essential oil and its major component
(Academic Press Inc., 2019) Somenath Das; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Anand Kumar Chaudhari; Neha Upadhyay; Akanksha Singh; Deepika; Nawal Kishore Dubey
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[rad] 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. © 2019 Elsevier Inc.
Antimicrobial, Aflatoxin B1 Inhibitory and Lipid Oxidation Suppressing Potential of Anethole-Based Chitosan Nanoemulsion as Novel Preservative for Protection of Stored Maize
(Springer, 2020) Anand Kumar Chaudhari; Vipin Kumar Singh; Somenath Das; Deepika; Bijendra Kumar Singh; Nawal Kishore Dubey
Aflatoxins (AFs) are the most frequent contaminants of maize and maize-based products, and its consumption can cause severe adverse effects to humans and animals. The efficacy of essential oils (EOs) and their bioactive compounds as potential antifungal agents has been well documented against food-borne fungi. This study evaluates the preservative potency of anethole-based chitosan nanoemulsion (Ant-eCsNe) to control deterioration of stored maize samples from fungal infestation, aflatoxin B1 (AFB1) contamination and lipid oxidation. Release study indicated a relatively good sustainable release profile for the encapsulated anethole after 10 days. The Ant-eCsNe showed improved efficacy against A. flavus (AF-LHP-VS8) and other common food-borne moulds and inhibited growth and AFB1 biosynthesis at 0.8 and 0.4 μL/mL, respectively. Ant-eCsNe caused concentration-dependent inhibition of ergosterol content and increased efflux of cellular ions (Ca+2, Mg+2 and K+) and 260 and 280 nm absorbing materials, suggesting damage of fungal plasma membrane. Inhibition of methylglyoxal in fungal cells treated with Ant-eCsNe signifies its novel antiaflatoxigenic mechanism of action. Ant-eCsNe exhibited strong in vitro DPPH• and ABTS+• scavenging activity with IC50 value 89.36 and 45.05 μL/mL, respectively, and inhibited lipid oxidation in stored maize samples. Further, Ant-eCsNe exhibited reasonably strong efficacy in preserving maize samples from fungal and AFB1 contamination during in vivo investigations and did not change the sensory attributes as well. Overall results revealed that Ant-eCsNe holds good potential to be applied as food preservative to reduce fungal and aflatoxin contamination causing deterioration of stored maize. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
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
(Springer Science and Business Media Deutschland GmbH, 2021) Deepika; Anand Kumar Chaudhari; Somenath Das; Vipin Kumar Singh; Jitendra Prasad; Nawal Kishore Dubey
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. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
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
(Springer, 2020) Akanksha Singh; Deepika; Anand Kumar Chaudhari; Somenath Das; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Ramani Kandasamy Shivalingam; Nawal Kishore Dubey
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. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Biological control of plant diseases: Opportunities and limitations
(Springer International Publishing, 2020) Akanksha Singh; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Deepika; Shikha Tiwari; Awanindra Dwivedi; Nawal Kishore Dubey
Plant diseases are important challenge to agriculture worldwide. Annually millions of tons of agricultural produce are lost due to the actions of plants pathogens. Past historical evidences are available showing the great mass migration and death of humans caused by the disease outbreak. Currently, several measures have been adopted to control the loss of crop productivity caused by fungal diseases. Physical and chemical approaches have gained huge success in managing the plant diseases, but being costly and toxic to natural environment in most of the cases, these are not preferred by the farmers. Moreover, the use of agrochemicals to control the plant pathogens has evoked the phenomenon of pest resistance and thus aggravating the seriousness of plant diseases and loss of crop productivity. To minimize the risks of synthetic chemicals, biological control measures have been introduced to control the fast multiplication of several plant diseases; however, under natural environmental conditions, their efficiency is very much affected. Plant systems have evolved several mechanisms to deal with the encountered pathogens. Enhancing the plant immunity against diseases caused by important plant pathogens by identifying and introducing the genes promoting the diseases resistance may serve as a good option in near future to control the plant disease for human welfare. © Springer Nature Switzerland AG 2020.
Co-encapsulation of Pimpinella anisum and Coriandrum sativum essential oils based synergistic formulation through binary mixture: Physico-chemical characterization, appraisal of antifungal mechanism of action, and application as natural food preservative
(Academic Press Inc., 2022) Somenath Das; Vipin Kumar Singh; Anand Kumar Chaudhari; Deepika; Abhishek Kumar Dwivedy; Nawal Kishore Dubey
The present study aimed to co-encapsulate binary synergistic formulation of Pimpinella anisum and Coriandrum sativum (PC) essential oils (0.75:0.25) into chitosan nanoemulsion (Nm-PC) with effective inhibition against fungal proliferation, aflatoxin B1 (AFB1) secretion, and lipid peroxidation in stored rice. Physico-chemical characterization of Nm-PC by SEM, FTIR, and XRD confirmed successful encompassment of PC inside the chitosan nanomatrix with efficient interaction by functional groups and reduction in crystallinity. Nm-PC showed superior antifungal, antiaflatoxigenic, and antioxidant activities over unencapsulated PC. Reduction in ergosterol biosynthesis and enhanced leakage of Ca2+, K+, Mg2+ ions and 260, 280 nm absorbing materials by Nm-PC fumigation confirmed irreversible damage of plasma membrane in toxigenic Aspergillus flavus cells. Significant diminution of methylglyoxal in A. flavus cells by Nm-PC fumigation illustrated biochemical mechanism for antiaflatoxigenic activity, suggesting future exploitation for development of aflatoxin resistant rice varieties through green transgenic technology. In silico findings indicated specific stereo-spatial interaction of anethole and linalool with Nor-1 protein, validating molecular mechanism for AFB1 inhibition. In addition, in situ investigation revealed effective protection of stored rice against fungal occurrence, AFB1 biosynthesis, and lipid peroxidation without affecting organoleptic attributes. Moreover, mammalian non-toxicity of chitosan entrapped PC synergistic nanoformulation could provide exciting potential for application as eco-smart safe nano-green food preservative. © 2022 Elsevier Inc.
Efficacy of Cinnamomum cassia essential oil against food-borne molds and aflatoxin B1 contamination
(Taylor and Francis Ltd., 2021) Akanksha Singh; Deepika; Anand Kumar Chaudhari; Somenath Das; Jitendra Prasad; Abhishek Kumar Dwivedy; Nawal Kishore Dubey
The present study deals with the antifungal and antiaflatoxigenic potential of Cinnamomum cassia essential oil (CCEO) against aflatoxigenic food borne Aspergillus flavus strain (AF-LHP-PE-4), and probable mode of action including the safety profile on male mice. CCEO completely inhibited fungal growth and aflatoxin B1 secretion at its minimum inhibitory concentration (0.06 µL/mL). CCEO inhibited ergosterol biosynthesis in cell membranes and also disturbed the membrane fluidity. Significant enhancement in leakage of cellular ions and 260 and 280 nm absorbing cellular materials in response to increased concentrations of CCEO indicated the plasma membrane as the probable site of antifungal toxicity. The antiaflatoxigenic potency of CCEO was confirmed in terms of reduction in the level of cellular methylglyoxal (MG), the inducer of aflatoxin. Antioxidant activity of CCEO was confirmed through DPPH free radical scavenging activity as well as total phenolic content. Chemical profiling of CCEO by gas chromatography-mass spectrometry (GC-MS) analysis revealed the presence of cinnamaldehyde (84.01%) as the most abundant compound. CCEO exhibited a high LD50 (10410.75 µL/kg) on male mice, strengthening its favorable safety profile. This is the first report on CCEO as novel green preservative against food storage molds and aflatoxin B1 secretion. © 2020 Societá Botanica Italiana.
Eugenol loaded chitosan nanoemulsion for food protection and inhibition of Aflatoxin B1 synthesizing genes based on molecular docking
(Elsevier Ltd, 2021) Somenath Das; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Anand Kumar Chaudhari; Deepika; Nawal Kishore Dubey
The present investigation entails the fabrication and characterization of nanometric emulsion of eugenol (Nm-eugenol) encompassed into chitosan for assessing bio-efficacy in terms of in vitro antifungal actions, antiaflatoxigenic potential, and in situ preservative efficacy against Aspergillus flavus infestation and aflatoxin B1 (AFB1) mediated loss of dietary minerals, lipid triglycerides and alterations in composition of important macronutrients in stored rice. Nm-eugenol characterized by SEM, XRD, and FTIR exhibited biphasic burst release of eugenol. Reduction in ergosterol and methylglyoxal (AFB1-inducer) content after Nm-eugenol fumigation depicted biochemical mechanism of antifungal and antiaflatoxigenic activities. In silico 3D homology docking of eugenol with Ver-1 gene validated molecular mechanism of AFB1 inhibition. Further, significant protection of rice seeds from fungi, AFB1 contamination and preservation against loss of rice minerals, macronutrients and lipids during storage suggested deployment of chitosan as a biocompatible wall material for eugenol encapsulation and application as novel green preservative for food protection. © 2020 Elsevier Ltd
Fabrication, characterization and practical efficacy of Myristica fragrans essential oil nanoemulsion delivery system against postharvest biodeterioration
(Academic Press, 2020) Somenath Das; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Anand Kumar Chaudhari; Neha Upadhyay; Akanksha Singh; Deepika; Nawal Kishore Dubey
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. © 2019 Elsevier Inc.
Fabrication, characterization, and bioactivity assessment of chitosan nanoemulsion containing allspice essential oil to mitigate Aspergillus flavus contamination and aflatoxin B1 production in maize
(Elsevier Ltd, 2022) Anand Kumar Chaudhari; Vipin Kumar Singh; Somenath Das; Deepika; Nawal Kishore Dubey
The direct incorporation of essential oils (EOs) into real food system faces numerous challenges due to high volatility, intense aroma, and instability. This research aimed to enhance the stability and bio-efficacy of Pimenta dioica essential oil (PDEO) through encapsulation in chitosan (CN) nanoemulsion. The nanoemulsion (CN-PDEO) was fabricated through ionic-gelation technique. CN-PDEO exhibited high nanoencapsulation efficiency (85.84%) and loading capacity (8.26%) with the particle size ranging between 18.53 and 70.56 nm. Bio-efficacy assessment results showed that CN-PDEO presented more effective antifungal and antiaflatoxigenic activity against Aspergillus flavus (AF-LHP-VS8) at lower doses (1.6 and 1.0 µL/mL) than the pure PDEO (2.5 and 1.5 µL/mL, respectively, p < 0.05). Additionally, CN-PDEO preserved model food (maize) from aflatoxin B1 and lipid peroxidation without altering their sensory properties during storage with high safety profile (p < 0.05). Overall results concluded that CN-PDEO can be recommended for shelf-life extension of stored maize and other food commodities. © 2021 Elsevier Ltd
Foodborne microbial toxins and their inhibition by plant-based chemicals
(Elsevier, 2020) Somenath Das; Anand Kumar Chaudhari; Akanksha Singh; Deepika; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Nawal Kishore Dubey
Spoilage of food commodities by different microbes and associated toxins may cause potential health risks, particularly in tropical and subtropical countries. To control food spoilage, various synthetic chemicals with potential to induce ill effects on human and environmental integrity have been utilized indiscriminately. On the other hand, phytochemicals extracted from different medicinally important plants may be explored as green alternatives for prevention of microbial infestation of food commodities and toxin production. Phytochemicals such as terpenoids, phenols, glycosides, glucosinolates, alkaloids, lactones, and essential oils can regulate different key regulatory genes in food contaminating bacteria and fungi. So far, different classical as well as high throughput modern techniques have been employed to detect pathogenic microbes and their toxins in contaminated food system. The present article deals with the efficacy of phytochemicals as a potential green preservative together with the emphasis on their application as inhibitor of foodborne microbial toxins. © 2020 Elsevier Inc. All rights reserved.
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
(Elsevier Ltd, 2020) Anand Kumar Chaudhari; Vipin Kumar Singh; Somenath Das; Deepika; Jitendra Prasad; Abhishek Kumar Dwivedy; Nawal Kishore Dubey
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. © 2020 Elsevier Ltd
Laurus nobilis essential oil nanoemulsion-infused chitosan: A safe and effective antifungal agent for masticatory preservation
(Elsevier B.V., 2023) Akanksha Singh; Somenath Das; Anand Kumar Chaudhari; Deepika; Monisha Soni; Arati Yadav; Abhishek Kumar Dwivedy; Nawal Kishore Dubey
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. © 2023 The Authors
Nanoencapsulated Monarda citriodora Cerv. ex Lag. essential oil as potential antifungal and antiaflatoxigenic agent against deterioration of stored functional foods
(Springer, 2020) Deepika; Akanksha Singh; Anand Kumar Chaudhari; Somenath Das; Nawal Kishore Dubey
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. © 2020, Association of Food Scientists & Technologists (India).
Nanoencapsulated Petroselinum crispum essential oil: Characterization and practical efficacy against fungal and aflatoxin contamination of stored chia seeds
(Elsevier Ltd, 2021) Deepika; Anand Kumar Chaudhari; Akanksha Singh; Somenath Das; Nawal Kishore Dubey
The present study explores the practical efficacy of chitosan (CS) nanoemulsion loaded with Petroselinum crispum essential oil (CS-PEO). Since, nanoencapsulation of EO is an emerging field in food science, the PEO was encapsulated into CS nanoemulsion and investigated their efficacy against fungal, aflatoxin B1 (AfB1) contamination and lipid peroxidation of stored Salvia hispanica (chia seeds). The GC/MS analysis of PEO confirmed the presence of carvacrol (48.45%) as the major component. The successful encapsulation of PEO was confirmed through FTIR, XRD, and SEM analysis. During in vitro investigation, CS-PEO completely inhibited the growth of Aspergillus flavus (AF-LHP-SH1) as well as eleven other storage fungi at 1.0 μL/mL and AfB1 production at 0.75 μL/mL. The reduction of cellular ergosterol followed by subsequent release of cellular constituents confirmed plasma membrane as possible target for antifungal mode of action of CS-PEO. The inhibition of methylglyoxal shed light on novel antiaflatoxigenic mode of action. Further, CS-PEO showed remarkable antioxidant activity with IC50 value equivalent to 14.24 μL/mL as measured through DPPH assay. During in situ investigation, CS-PEO completely inhibited the production of AfB1 and lipid peroxidation in treated chia seeds for one year of storage, and exhibited satisfactory safety profile (LD50 = 26, 830 μL/kg body weight) in mammalian model (mice). Based on overall results, it can be concluded that CS-PEO could be recommended for industrial scale application in the management of fungal and aflatoxin mediated loss of stored chia seeds. © 2021 Elsevier Ltd
Nanostructured Pimpinella anisum essential oil as novel green food preservative against fungal infestation, aflatoxin B1 contamination and deterioration of nutritional qualities
(Elsevier Ltd, 2021) Somenath Das; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Anand Kumar Chaudhari; Deepika; Nawal Kishore Dubey
Application of synthetic preservatives to control the contamination of stored food commodities with aflatoxin B1 causing considerable loss in nutritional value is a major challenge. However, employment of essential oils for protecting food commodities is much limited due to high volatility, and increased susceptibility to oxidation. Therefore, objective of the present investigation was encapsulation of Pimpinella anisum essential oil in chitosan nanobiopolymer (CS-PAEO-Nm) to improve its bioefficacy, and sensorial suitability for application in food system. The synthesized CS-PAEO-Nm was characterized through SEM, FTIR, and XRD and evaluated for improved biological activity. The CS-PAEO-Nm exhibited improved antifungal (minimum inhibitory concentration = 0.08 μL/mL) and antiaflatoxigenic (minimum aflatoxin inhibitory concentration = 0.07 μL/mL) activities. CS-PAEO-Nm treatment significantly inhibited ergosterol, enhanced leakage of ions and induced impairment in defense enzymes (p < 0.05). In situ minerals and macronutrient preservation, and acceptable sensorial characteristics suggested possible recommendation of nanoencapsulated PAEO as potential safe green food preservative. © 2020 Elsevier Ltd
Unveiling the cellular and molecular mode of action of Melaleuca cajuputi Powell. essential oil against aflatoxigenic strains of Aspergillus flavus isolated from stored maize samples
(Elsevier Ltd, 2022) Anand Kumar Chaudhari; Vipin Kumar Singh; Somenath Das; Anupam Kujur; Deepika; Nawal Kishore Dubey
This study aimed to reveal the bio-efficacy of Melaleuca cajuputi essential oil (McEO) against aflatoxigenic fungi and lipid peroxidation causing deterioration of stored maize samples. Three different toxigenic strains of Aspergillus flavus, namely AF-LHP-M2, AF-LHP-SP2, and AF-LHP-VS8 were investigated. Gas chromatography-mass spectrometry (GC-MS) analysis of EO revealed the presence of α-pinene (49.24%) as major compound. Investigation on efficacy showed that McEO exhibited remarkable inhibitory activity against growth and AFB1 production by AF-LHP-M2 (2.0 and 1.4 μL mL−1, respectively), AF-LHP-SP2 (1.2 and 1.0 μL mL−1, respectively), and AF-LHP-VS8 (0.8 μL mL−1) (p < 0.05). The McEO inhibited fungal growth via inhibition of ergosterol biosynthesis, cellular constituents' leakage, and damage of mitochondrial membrane potential, while AFB1 production by inhibition of intracellular methylglyoxal. Further, molecular docking study was carried out to unveil the binding affinities of major compounds with the target protein Nor-1 (primarily catalyze an important step in AFB1 biosynthesis), and the results revealed good correlation with the experimental findings. In addition, McEO showed significantly (p < 0.05) higher DPPH• and ABTS•+ scavenging activity with IC50 values 3.16 and 4.29 μL mL−1, respectively. Interestingly, McEO inhibited AFB1 production, and malondialdehyde content in fumigated maize samples without significantly (p < 0.05) changing their sensory attributes, ascertaining its efficacy in food system with high safety profile (LD50 = 1800 mg kg−1 body weight) on mice model. The overall results proved McEO's potential as natural food preservative of stored food products. © 2022 Elsevier Ltd
Use of Green Chemicals in Pest and Disease Management
(Springer Singapore, 2022) S. Subhash; K.V. Raghavendra; Rekha Balodi; Deepika; N.K. Dubey
To alleviate the biotic stress in crops, farmers rely on the use of synthetic pesticides. The indiscriminate use of synthetic chemical pesticides has posed adverse effects on the beneficial organisms, human beings, and other nontargeted organisms. The use of plant-derived green chemicals is believed to bring some relief to this situation. Besides being safer, green chemicals offer varied modes of action due to the variation in their chemical composition, and unlike synthetic ones, the green chemicals due to their biodegradable nature do not persist in the environment for over longer period of time. Historically, green chemicals such as rotenone, pyrethrum, azadirachtin, veratrines, ryanodine, and nicotine have been used for the management of various insect pests. Green chemicals exhibit a myriad of modes of actions against insects including rapid or slow kill, feeding inhibition, repellents, oviposition deterrent, and growth regulatory effects. Besides insect pests, various green chemicals have been demonstrated to possess antibiotic, antifungal, nematicidal, and herbicidal activities. Although green chemicals have many advantages over the synthetic pesticides, green chemicals suffer from very short residual life due to UV-induced degradation. Many aspects are being explored to increase the usage of green chemicals in IPM in a sustainable manner. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022
Zingiber zerumbet L. essential oil-based chitosan nanoemulsion as an efficient green preservative against fungi and aflatoxin B1 contamination
(Blackwell Publishing Inc., 2021) Deepika; Akanksha Singh; Anand Kumar Chaudhari; Somenath Das; Nawal Kishore Dubey
Abstract: 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. © 2020 Institute of Food Technologists®