Anethum graveolens Essential Oil Encapsulation in Chitosan Nanomatrix: Investigations on In Vitro Release Behavior, Organoleptic Attributes, and Efficacy as Potential Delivery Vehicles Against Biodeterioration of Rice (Oryza sativa L.)

Abstract

The study deals with first time report on encapsulation of chemically characterized Anethum graveolens essential oil within chitosan nanomatrix (Nm-AGEO) using ionic gelation technique to enhance the antimicrobial, antiaflatoxigenic, antioxidant, and in situ efficacy against stored rice biodeterioration. GC-MS analysis of AGEO revealed dill apiol (33.79%), carvone (27.19%), and limonene (13.76%) as major components. Nm-AGEO characterization through scanning electron microscopy (SEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FT-IR) confirmed successful encapsulation of AGEO within chitosan as an encapsulant. Biphasic and sustained release pattern reflected controlled volatilization of bioactives, helpful in shelf-life extension of stored food commodities. Nm-AGEO caused significant impairment in fungal ergosterol biosynthesis and enhanced leakage of vital ions indicating destabilization in plasma membrane integrity. Inhibition of methylglyoxal (aflatoxin inducer) biosynthesis by Nm-AGEO confirmed novel antiaflatoxigenic mechanism of action, suggesting its future exploitation for development of aflatoxin-resistant rice varieties through green transgenics. Nm-AGEO induced impairment in antioxidant defense enzymes (SOD, CAT) and non-enzymatic defense biomolecules GSH and GSSG revealing biochemical mechanism of action. In silico modeling of carvone and limonene with Omt-A and Ver-1 genes suggested molecular mechanism of aflatoxin inhibition. Treatment of rice samples with Nm-AGEO caused significant protection from aflatoxin B1 contamination and lipid peroxidation without altering organoleptic properties. Moreover, favorable safety profile for mammalian system and non-phytotoxic nature of chitosan-fabricated AGEO nanoemulsion-based delivery system recommend attention of food industries for its formulation as potential green preservative. Graphical abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.