EVALUATION OF GRADING, DEPURATION, AND STORAGE TIME ON CRAWFISH MORTALITY DURING COLD-STORAGE

Red swamp crawfish (Procambarus clarkii Girard) were subjected to three postharvest treatments (grading, grading and purging, or no additional treatment) and three cold storage (4 +/- 0.2-degrees-C) periods (2, 4, or 6 days) in a factorial arrangement to determine the effects of these factors on crawfish mortality during cold storage. Significant differences were observed for both main effects. Mean mortalities during cold storage were 10.5, 10.3, and 19.5% for the control, graded, and graded/purged groups, respectively. Mean percentage loss of 7.8, 10.8, and 21.7% were observed for the 2-, 4-, and 6-day periods of cold storage, respectively. Crawfish that were graded and then purged for 24 hr and crawfish held for 6 days in a cooler had significantly higher mean mortalities during cold storage. An additional mean mortality of 11.6% was observed during the 24-hr purge period. Overall, mortality losses were generally highest early in the harvest season and declined over time. Results from this research demonstrate that substantial loss can occur both during and after the purging process and present evidence to rebut the idea that purging may be beneficial in increasing the shelf life of crawfish during cold storage.