Shikha Tiwari

Bio: Shikha Tiwari is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Food spoilage & Aspergillus flavus. The author has an hindex of 2, co-authored 7 publications receiving 8 citations.

Essential oils and their nanoformulations as green preservatives to boost food safety against mycotoxin contamination of food commodities: a review.

Abstract: Postharvest food spoilage due to fungal and mycotoxin contamination is a major challenge in tropical countries, leading to severe adverse effects on human health. Because of the negative effects of synthetic preservatives on both human health and the environment, it has been recommended that chemicals that have a botanical origin, with an eco-friendly nature and a favorable safety profile, should be used as green preservatives. Recently, the food industry and consumers have been shifting drastically towards green consumerism because of their increased concerns about health and the environment. Among different plant-based products, essential oils (EOs) and their bioactive components are strongly preferred as antimicrobial food preservatives. Despite having potent antimicrobial efficacy and preservation potential against fungal and mycotoxin contamination, essential oils and their bioactive components have limited practical applicability caused by their high volatility and their instability, implying the development of techniques to overcome the challenges associated with EO application. Essential oils and their bioactive components are promising alternatives to synthetic preservatives. To overcome challenges associated with EOs, nanotechnology has emerged as a novel technology in the food industries. Nanoencapsulation may boost the preservative potential of different essential oils by improving their solubility, stability, and targeted sustainable release. Nanoencapsulation of EOs is therefore currently being practiced to improve the stability and bioactivity of natural products. The present review has dealt extensively with the application of EOs and their nanoformulated products encapsulated in suitable polymeric matrices, so as to recommend them as novel green preservatives against foodborne molds and mycotoxin-induced deterioration of stored food commodities. © 2021 Society of Chemical Industry.

Chemically characterized nanoencapsulated Homalomena aromatica Schott. essential oil as green preservative against fungal and aflatoxin B1 contamination of stored spices based on in vitro and in situ efficacy and favorable safety profile on mice

Abstract: Present study deals with the efficacy of nanoencapsulated Homalomena aromatica essential oil (HAEO) as a potent green preservative against toxigenic Aspergillus flavus strain (AF-LHP-NS 7), storage fungi, AFB1, and free radical-mediated deterioration of stored spices. GC–MS analysis revealed linalool (68.51%) as the major component of HAEO. HAEO was encapsulated into chitosan nanomatrix (CS-HAEO-Ne) and characterized through SEM, FTIR, and XRD. CS-HAEO-Ne completely inhibited A. flavus growth and AFB1 biosynthesis at 1.25 μL/mL and 1.0 μL/mL, respectively in comparison to unencapsulated HAEO (1.75 μL/mL and 1.25 μL/mL, respectively). CS-HAEO-Ne caused significant reduction in ergosterol content in treated A. flavus and provoked leakage of cellular ions (Ca+2, Mg+2, and K+) as well as 260 nm and 280 nm absorbing materials. Depletion of methylglyoxal level in treated A. flavus cells illustrated the novel antiaflatoxigenic efficacy of CS-HAEO-Ne. CS-HAEO-Ne exhibited superior antioxidant efficacy (IC50 (DPPH) = 4.5 μL/mL) over unencapsulated HAEO (IC50 (DPPH) = 15.9 μL/mL) and phenolic content. CS-HAEO-Ne depicted excellent in situ efficacy by inhibiting fungal infestation, AFB1 contamination, lipid peroxidation, and mineral loss with acceptable sensorial profile. Moreover, broad safety paradigm (LD50 value = 7150.11 mg/kg) of CS-HAEO-Ne also suggests its application as novel green preservative to enhance shelf life of stored spices.

Encapsulation of Essential Oils - A Booster to Enhance their Bio-efficacy as Botanical Preservatives

Abstract: 175 DOI: http://dx.doi.org/10.37398/JSR.2020.640125 Abstract: Essential oils (EOs) and their bioactive components are safer and novel formulations used as green preservative in food industries but their rapid volatility and high instability in varying environmental conditions pose a major hurdle for large scale practical application. Recently, different encapsulation technologies have been recommended as the booster for improvement of EOs bio-efficacy. The present article deals with some major encapsulation techniques and their role in enhancing bio-efficacy of EOs being used as botanical preservatives.

Biological Control of Plant Diseases: Opportunities and Limitations

Abstract: 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.

Green synthesis of silver nanoparticles using Eranthemum Pulchellum (Blue Sage) aqueous leaves extract: Characterization, evaluation of antifungal and antioxidant properties

Abstract: Background: Nanoparticles modulate several physiochemical and biological properties. In this regard, silver nanoparticles (AgNPs) have shown remarkable applications. The present research work comprises green synthesis of AgNPs using aqueous leaves extract of Eranthemum pulchellum and evaluation of its efficacy as antifungal and antioxidant agents. Methods: Synthesized AgNPs have been characterized by Fourier Transforms Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet-visible spectrophotometry. Qualitative phytochemical analysis of aqueous leaves extract of E. pulchellum and FTIR spectrum of the synthesized AgNPs suggest about the presence of different phytochemicals and functional groups, respectively, which are responsible for reducing silver ions as well as capping and stabilizing synthesized nanoparticles. Results: The wavelength of maximum absorbance of AgNPs solution near to 439 nm indicates the spherical morphology. XRD infers about average crystalline size of the synthesized AgNPs to be ~12 nm. Selected area electron diffraction pattern of the synthesized AgNPs shows four visible diffraction rings corresponding to (111), (200), (220), and (311) set of planes which are attributed to face centered cubic metallic silver. The size and spherical shape of the synthesized AgNPs have been further determined by TEM. The synthesized AgNPs have shown a significant antifungal activity against Aspergillus flavus (AF-LHP-NS7) strain with minimum inhibitory concentration value of 200 μg/mL. The synthesized AgNPs have also shown strong antioxidant efficacy through Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid assay with IC50 value of 462.56 μg/mL. Conclusions: The present study shows a green and facile synthesis of AgNPs. Leaves extract of E. pulchellum has been first time utilized as efficient reductant for the AgNPs synthesis. These AgNPs have shown potent antifungal and antioxidant activity.

Biological Control of Plant Pathogens: A Global Perspective

Abstract: The increase in the world population has generated an important need for both quality and quantity agricultural products, which has led to a significant surge in the use of chemical pesticides to fight crop diseases. Consumers, however, have become very concerned in recent years over the side effects of chemical fungicides on human health and the environment. As a result, research into alternative solutions to protect crops has been imposed and attracted wide attention from researchers worldwide. Among these alternatives, biological controls through beneficial microorganisms have gained considerable importance, whilst several biological control agents (BCAs) have been screened, among them Bacillus, Pantoea, Streptomyces, Trichoderma, Clonostachys, Pseudomonas, Burkholderia, and certain yeasts. At present, biopesticide products have been developed and marketed either to fight leaf diseases, root diseases, or fruit storage diseases. However, no positive correlation has been observed between the number of screened BCAs and available marketed products. Therefore, this review emphasizes the development of biofungicides products from screening to marketing and the problems that hinder their development. Finally, particular attention was given to the gaps observed in this sector and factors that hamper its development, particularly in terms of efficacy and legislation procedures.

Essential oils and their nanoformulations as green preservatives to boost food safety against mycotoxin contamination of food commodities: a review.

Abstract: Postharvest food spoilage due to fungal and mycotoxin contamination is a major challenge in tropical countries, leading to severe adverse effects on human health. Because of the negative effects of synthetic preservatives on both human health and the environment, it has been recommended that chemicals that have a botanical origin, with an eco-friendly nature and a favorable safety profile, should be used as green preservatives. Recently, the food industry and consumers have been shifting drastically towards green consumerism because of their increased concerns about health and the environment. Among different plant-based products, essential oils (EOs) and their bioactive components are strongly preferred as antimicrobial food preservatives. Despite having potent antimicrobial efficacy and preservation potential against fungal and mycotoxin contamination, essential oils and their bioactive components have limited practical applicability caused by their high volatility and their instability, implying the development of techniques to overcome the challenges associated with EO application. Essential oils and their bioactive components are promising alternatives to synthetic preservatives. To overcome challenges associated with EOs, nanotechnology has emerged as a novel technology in the food industries. Nanoencapsulation may boost the preservative potential of different essential oils by improving their solubility, stability, and targeted sustainable release. Nanoencapsulation of EOs is therefore currently being practiced to improve the stability and bioactivity of natural products. The present review has dealt extensively with the application of EOs and their nanoformulated products encapsulated in suitable polymeric matrices, so as to recommend them as novel green preservatives against foodborne molds and mycotoxin-induced deterioration of stored food commodities. © 2021 Society of Chemical Industry.

Nanoparticles—Attractive Carriers of Antimicrobial Essential Oils

Abstract: Microbial pathogens are the most prevalent cause of chronic infections and fatalities around the world. Antimicrobial agents including antibiotics have been frequently utilized in the treatment of infections due to their exceptional outcomes. However, their widespread use has resulted in the emergence of multidrug-resistant strains of bacteria, fungi, viruses, and parasites. Furthermore, due to inherent resistance to antimicrobial drugs and the host defence system, the advent of new infectious diseases, chronic infections, and the occurrence of biofilms pose a tougher challenge to the current treatment line. Essential oils (EOs) and their biologically and structurally diverse constituents provide a distinctive, inexhaustible, and novel source of antibacterial, antiviral, antifungal, and antiparasitic agents. However, due to their volatile nature, chemical susceptibility, and poor solubility, their development as antimicrobials is limited. Nanoparticles composed of biodegradable polymeric and inorganic materials have been studied extensively to overcome these limitations. Nanoparticles are being investigated as nanocarriers for antimicrobial delivery, antimicrobial coatings for food products, implantable devices, and medicinal materials in dressings and packaging materials due to their intrinsic capacity to overcome microbial resistance. Essential oil-loaded nanoparticles may offer the potential benefits of synergism in antimicrobial activity, high loading capacity, increased solubility, decreased volatility, chemical stability, and enhancement of the bioavailability and shelf life of EOs and their constituents. This review focuses on the potentiation of the antimicrobial activity of essential oils and their constituents in nanoparticulate delivery systems for a wide range of applications, such as food preservation, packaging, and alternative treatments for infectious diseases.