Microbial quality of roe from white fish

Summary

The Norwegian whitefish industry has a long tradition of preserving fish roe. Examples of preservation methods are salting, sugarsalting, freezing, and thermal treatment. Roe from cod and saithe is an essential ingredient in caviar, while roe from lumpfish can, e.g., used as an aperitif or similar. Regardless of species, roe contains high levels of fat and protein and is, therefore, a rich medium for microbial growth that can contribute to negative properties of the product. This project aims to get an overview of research-based studies on the microbiological quality of roe products from cod, lumpfish, saithe, and ling. Most studies have been performed on roe from cod and lumpfish, and only one on roe from the ling. No scientific studies were found on roe from saithe. Most studies on roe quality focus on the biochemical processes that occur after the roe have been added a preservative, salt, or a sugar-salt mixture. To provide a more comprehensive overview of what can affect microbiological quality, descriptions of methods for handling and preservation of roe have been included. The fish industry has a long tradition of oral knowledge transfer, and this also applies to the handling of roe. Key buyers of roe, like Mills AS and ABBA Seafood/Orkla Foods Sverige AB, have prepared recipes that describe how the roe they buy should be handled and preserved. Recipes for cod and saithe roe processing from ABBA Seafood's recipes are included in the report. In order to raise awareness of microbial quality deterioration of roe and how this is affected by handling and preservation, it is suggested to develop a "best practice protocol" which can be applied in the industry's day-to-day work with roe. Such a protocol can be a positive contribution to the oral tradition of knowledge transfer, and thereby improve quality and handling processes of roe.