Chitosan extraction using green technology and it’s application for preservation of fresh coconut slices

Abstract

The extraction of chitosan from shrimp shells using environmentally friendly methods offers a sustainable alternative to conventional techniques that rely on harsh chemicals like hydrochloric acid and sodium hydroxide. This thesis explores the extraction of chitosan through a green technology approach involving a two-step demineralization process utilizing citric acid and Deep Eutectic Solvent (DES). The chitosan thus obtained was employed as a coating agent for the preservation of fresh coconut slices, a perishable commodity with a notoriously short shelf life.The extracted chitosan was formulated into a coating solution consisting of 25% glycerol, 1% acetic acid, and 1% chitosan. The application of this coating on fresh coconut slices resulted in a shelf life extension to approximately 20 days when stored in zip lock bags under refrigerated ( 8 °C) conditions. Comparatively, coconut slices coated with commercially purchased chitosan from Loba Chemie PVT LTD demonstrated an extended shelf life of nearly one month under similar conditions.This research also undertakes a comprehensive comparison between the lab-extracted chitosan and the commercially obtained counterpart. Analytical techniques such as Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction (XRD) were employed to characterize the chitosan samples. Furthermore, the efficacy of the chitosan coatings was evaluated based on microbial spoilage, sensory properties and moisture loss of the treated coconut slices.The findings underscore the potential of green technology in producing high-quality chitosan, which is effective in extending the shelf life of fresh produce. This study not only contributes to the field of sustainable biopolymer extraction but also highlights practical applications in food preservation, promoting both environmental and economic benefits.