Influence of Epigallocatechin Gallate on Quality of Cooked Harpiosquillid Mantis Shrimp (Harpiosquilla raphidea) Subjected to Multiple Freeze-Thaw Cycles

Effects of epigallocatechin gallate (EGCG) at 200 or 400 ppm on quality changes of cooked Harpiosquillid mantis shrimp (Harpiosquilla raphidea) (CHMS) meat subjected to varying freeze-thaw cycles (F-T-C; 0, 1, 3, and 5) were studied. With augmenting F-T-C, the CHMS meat underwent deterioration to higher extent as indicated by upsurges in exudate loss, tougher texture along with increased microbial counts. The addition of EGCG could retard those changes in a dose-dependent manner. Furthermore, EGCG prevented microbial growth as ascertained by lower counts and total volatile basic nitrogen (TVB) content. Lipid oxidation was also impeded in the presence of EGCG, especially at a high concentration as evidenced by lowered malondialdehyde (MDA), while maintaining polyunsaturated fatty acids, particularly EPA and DHA when F-T-C raised. Total disulfide bond content and surface hydrophobicity of CHMS added with EGCG were lower than those of the control. Those alterations were more retarded as EGCG concentration increased. Therefore EGCG at 400 ppm effectively prevented quality loss of CHMS meat during repeated F-T process.