GLUCOSE-OXIDASE CATALASE SOLUTION FOR ON-BOARD CONTROL OF SHRIMP MICROBIAL SPOILAGE - MODEL STUDIES

The potential of an immersion system of glucose oxidase (GOX, 1 unit/mL) and catalase (CAT) added to 4% w/v glucose in artificial seawater was determined for on-board shrimp preservation. Fresh shrimp were frozen, radiation-sterilized, thawed by adding artificial seawater and inoculated with Pseudomonas fluorescens (10(4) CFU/g shrimp). Samples were stored at 1-degrees-C and treated after 24 hr or left as controls. Changes in shrimp and solution were monitored by total plate counts, ammonia and total volatile nitrogen. Solution discoloration due to shrimp melanosis was followed spectrophotometrically. Microbial lag phase was extended almost-equal-to 5 d and after 14 d, GOX/CAT had reduced browing by almost-equal-to 80% and inhibited ammonia and total volatile nitrogen production. Due to increase in nitrogen compounds, the enzyme solution should be replaced after 14 days.