A new application of deep eutectic solvent (DES) in fish preservation

Technology in fish preservation had gone through various scope in food industry. Application of new green chemistry of deep eutectic solvent (DES) as preservative capable to help in the prevention of fish contamination by pathogenic bacteria. The aims of this study were including the synthesis of DES, the evaluation of antibacterial activity and sterility testing of the DES using fish samples. The synthesis of choline chloride-based DES was prepared by mixing with acetic acid and oxalic acid respectively. Further testing was done using disc diffusion method for the analysis of the solvent's antibacterial activity towards E. coli, S. aureus, B. subtilis, S. Typhi and K. pneumonia. The sterility evaluation on the preservative solvent was carried out using fish samples in different temperature and time of storage. Results analysis showed potential of the DES in antibacterial activity even at low concentration of mixture. Sterility test showed promising result by maintaining pH of the solvent at 6-7. Reduction of bacteria concentration was found in the bacterial-spiked fish samples when preserved in the DES mixture. Thus, the study proved the potential of DES as a good preservative for fish compared with the controls from single component of choline chloride, acetic acid and oxalic acid respectively..