Changes in the Microbial Quality of Nephrops norvegicus during Processing for Retail Packs

Area of Science:

• Marine Biology
• Food Microbiology
• Seafood Quality Control

Background:

• Assessing microbial quality is crucial for seafood safety and shelf-life.
• Nephrops norvegicus (prawns) are commercially important, necessitating quality monitoring.
• Freezing and processing steps can impact bacterial loads and indicators.

Purpose of the Study:

• To determine the microbial quality of whole Nephrops norvegicus tails post-freezing.
• To evaluate the effects of processing (freezing, breading, battering) on microbial counts.
• To assess the utility of the coliform to total viable count ratio as a contamination indicator.

Main Methods:

• Microbial analysis of whole prawn tails after initial freezing.
• Monitoring of total viable counts (TVC) and coliforms during processing into scampi.
• Statistical comparison of microbial loads before and after processing steps.

Main Results:

• Mean TVC decreased from 1.3 × 10^6/g in whole tails to 9.7 × 10^5/g in processed scampi.
• Peeling and polyphosphate treatment significantly reduced bacterial counts; gutting/sorting increased them.
• The ratio of coliforms to TVC increased during processing, suggesting contamination.

Conclusions:

• Overall processing resulted in an insignificant change in TVC.
• The coliform:TVC ratio is a potential indicator of contamination source and raw material quality.
• Both TVC and coliform counts are necessary for comprehensive microbial quality assessment.