Abstract

LIGNIN NANOPARTICLES FOR PRESERVATION OF INDIAN MACKEREL

Arati N. Parange* and Dr. R. C. Patil

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Abstract

This study investigates the preparation, characterization, and application of lignin nanoparticles (LNPs) derived from Cocos nucifera for the preservation of Indian mackerel (Rastrelliger kanagurta). LNPs were synthesized via the alkaline precipitation method and confirmed through qualitative colorimetric assays, dynamic light scattering, zeta potential analysis, and transmission electron microscopy. Post-sonication, the nanoparticles exhibited a reduced mean particle size of 410 nm and a zeta potential of -3.3 mV, indicating moderate stability. Antibacterial activity assessed through broth and agar dilution methods revealed effective inhibitory action against E. coli O157:H7, S. aureus, P. paraeruginosa, V. parahaemolyticus, and S. typhi, with minimum inhibitory concentrations ranging from 500–1700 mg/L. Preservation efficacy of LNPs was evaluated through chemical quality assessments of Indian mackerel over time, including moisture, pH, fat, peroxide value (PV), and protein content. Compared to untreated and standard preservative-treated samples, LNP-treated fish retained significantly higher moisture and protein levels and exhibited lower PV increases, indicating reduced lipid oxidation. Non-parametric statistical analysis (Shapiro-Wilk, Kruskal-Wallis, Dunn’s post-hoc) confirmed significant improvements (p < 0.001) in key quality parameters, excluding fat content (p > 0.05), across treatments. These findings demonstrate that LNPs from coconut biomass are an effective, eco-friendly alternative to conventional chemical preservatives, offering enhanced antimicrobial protection and shelf-life extension for fish preservation applications.

Keywords: Lignin, nanoparticles, coconut, Cocos nucifera L., Indian Mackerel.