Isolation, characterization, and utilization of Tardi (Dioscorea bellophylla) starch in the development of antimicrobial films incorporated with silver nanoparticles

Authors: Divyanshi Thakur Rahul Das; Kamlesh Prasad

Book: Sustainable Food Innovations: Product Development, Packaging, and Waste Valorization

Editors: K. Prasad, S. Shekhar and H. K. Sharma

Publisher: SLIET Longowal

Publication year: 2026

Publication date: 2026-10-02

ISBN: 978-81-990304-2-8 (e-book); 978-81-990304-3-5 (hardback)

Chapter pages: 97–124

DOI: To be added after DOI registration.

Abstract

Tuber and root crops are important food crops, mainly in tropics and subtropics. This study analyzed starch extract and flour of Tardi (Dioscorea bellophylla) and utilized the extracted Tardi starch (TS) to develop films incorporated with varying proportions (0.5%, 1%, 1.5%, and 2.0%) of silver nanoparticle (AgNPs) via the casting method. The results indicated that TS exhibited low fat, fiber, ash, and protein than flour but demonstrated superior solubility and swelling power. The amylose and amylopectin content were 24.56%, and 75.44%, respectively, with starch granules showed an elliptical morphology (35.212 μm). Rheological analysis revealed better pasting than Tardi flour (TF). TS had high gelatinization temperature, enthalpy, and peak viscosity, demonstrating excellent potential for industrial applications. AgNPs incorporation significantly influenced mechanical, functional, and the structural characteristics of TS films. FTIR analysis revealed slight peak shifts, while color assessment showed AgNPs films had an off-white tint. Transparency showed significant decrease as the concentration of AgNPs increased. Additionally, water vapor permeability (WVP) as well as solubility were decreased, while tensile strength (TS) improved. The films showed significant antimicrobial activity against gram-positive bacteria, making them effective for pathogen control. Given their enhanced properties, these films have potential applications as biodegradable barrier/coating on fruits and vegetables, extending shelf life as well as maintaining food safety.

Keywords: Tardi; flour; starch extract; silver nanoparticle; food coating; antimicrobial properties

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