Browsing by Author "Mayondi Grace Ramsdam"

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Antifungal and antioxidant activity of plant based essential oils on Aspergillus flavus Link (Trichocomaceae) isolated from stored maize grains of Meghalaya
(Taylor and Francis Ltd., 2021) Mayondi Grace Ramsdam; Anand Kumar Chaudhari; Vipin Kumar Singh; Mamtaj S. Dkhar; Highland Kayang; Nawal Kishore Dubey; Bhanu Prakash
Essential oils from five medicinal aromatic plants viz. Gaultheria fragrantissima Wall, Artemisia nilagirica Clarke, Curcuma longa Linn, Zingiber officinale Roscoe and Litsea cubeba (Lour.) Pers. were evaluated for their efficacy as antifungal agents against the growth of toxigenic Aspergillus flavus Link isolated from stored maize of Meghalaya. Antifungal activity of essential oils was evaluated by determining the Minimal inhibition concentration (MIC) and Minimal fungicidal concentration (MFC). Among the five essential oils tested, Litsea cubeba essential oil showed high antifungal activity with complete mycelia growth inhibition at 0.8µl/ml. Scanning Electron Microscopy of A. flavus exposed to oils showed hyphae and conidiophore damages. The essential oil exhibited antioxidant activity through DPPH (2,2-diphenyl-1-picrylhydrazyl) assay as IC50 value ranged between 0.59 and 14.44µl/ml and are non-phytotoxic during seed germination experiments with maize seeds. Based on the antifungal, antioxidant and non-phytotoxic potential, the tested essential oils may be recommended as eco-friendly seed protectants. © 2021 Informa UK Limited, trading as Taylor & Francis Group.
Assessment of chitosan biopolymer encapsulated α-Terpineol against fungal, aflatoxin B1 (AFB1) and free radicals mediated deterioration of stored maize and possible mode of action
(Elsevier Ltd, 2020) Anand Kumar Chaudhari; Akanksha Singh; Vipin Kumar Singh; Abhishek Kumar Dwivedy; Somenath Das; Mayondi Grace Ramsdam; Mumtaz S Dkhar; Highland Kayang; Nawal Kishore Dubey
This study reports enhanced efficacy of encapsulated α-Terpineol to control fungal, aflatoxin B1 (AFB1) and free radicals mediated deterioration of stored maize samples. The α-Terpineol loaded chitosan nanoemulsion (α-TCsNe) was characterized through SEM, FTIR and XRD techniques. The α-TCsNe exhibited enhanced antifungal activity against aflatoxin secreting strain of Aspergillus flavus (AF-LHP-S1) and 12 other food borne moulds as well as AFB1 production at 0.4 and 0.3 µL/mL, respectively. Further, α-TCsNe inhibited ergosterol synthesis, methylglyoxal (the aflatoxin enhancer) content and enhanced cellular contents release. α-TCsNe showed enhanced radical scavenging activity with IC50 value equivalent to 39.57 and 6.23 µL/mL for DPPH and ABTS, respectively. In addition, α-TCsNe completely inhibited AFB1 production in stored maize samples during in situ investigation. Overall, α-TCsNe holds a promising potential and can be recommended as a novel antifungal preservative to improve the shelf-life of stored maize samples against fungal and aflatoxin contamination. © 2019 Elsevier Ltd