Comparative analysis of physico-chemical and microbiological parameters in shelf-life evaluation of three cooked Australian prawns

Extending the shelf life of seafood can significantly improve product availability and reduce waste across the supply chain. However, reliable and standardized tools are needed to assess freshness and determine suitability for consumption. This study develops and validates, to our knowledge, the firstgeneric Quality Index Method (QIM) specifically for cooked and frozen Australian prawns, including Endeavour Prawns (EP), Western King Prawns (KP), and Brown Tiger Prawns (TP). The QIM tool effectively differentiated freshness levels across species, with TP showing the fastest quality decline, followed by KP and EP. Based on QIM scores, the maximum recommended storage time was seven days for all species. Microbiological analysis supported these findings, with TP exhibiting the highest total viable aerobic and Pseudomonas counts, along with the highest total volatile basic nitrogen (TVB-N), indicating advanced spoilage. EP recorded elevated thiobarbituric acid reactive substances (TBARS), reflecting significant lipid oxidation. Moisture content and water activity remained relatively stable, while drip loss and pH increased over time. Color parameters showed KP retained a brighter appearance, whereas EP and TP exhibited higher a* and b* values. KP also displayed lower values for hardness, chewiness, and gumminess, suggesting a softer texture during storage. The QIM developed in this study offers a practical, cost-effective tool for seafood processors and quality assurance teams to monitor freshness and optimize cold chain management of cooked prawns. Its alignment with established physico-chemical and microbiological indicators supports its potential for broader application in industrial quality control systems. • Quality Index Method (QIM) model developed for three cooked Australian prawn species. • Maximum storage time estimated to be seven days • Tiger prawns showed high susceptibility for quality degradation • King prawns showed brightest colour and softer texture • QIM scoring system found to be consistent with traditional analytical methods