Consumers demand perch that have a delicate sweet flavour. Fish that have undesirable flavours are not marketable. Off flavours in fish present no danger to consumers, but off-flavour fish sold in the marketplace can result in the loss of markets and hinder market development.
These Product Standards are a set of guidelines to assist silver, jade and golden perch (perch) growers in marketing their products. Its purpose is to set industry standards for a range of product specifications for live, whole fresh chilled and processed (gilled & gutted and fillets) perch. Product specifications addressed include size gradings, defects, packaging and temperature requirements.
Introduction of standards for seafood products are gaining increasing acceptance, particularly in industries that are implementing supply chain management. The recent introduction of a Code of Practice for harvest prawn has resulted in considerable savings in the industry and a more effective supply chain.
The Standards build on the current industry draft Food Safety Plan and other HACCP based plans that growers may have implemented. Therefore it assumes the following practices:
Only chemicals approved by the appropriate authority* for aquaculture are to be used in the production of perch. Where chemicals have been used all chemical withholding periods are to be rigorously observed.
*In Australia the appropriate authority, at the time this information was published is the Australian Pesticides and Veterinary Medicines Authority, (APVMA)
Prior to harvesting, perch should not be feed for a minimum of two (2) days. The perch should be then transferred to a purging or holding tank where they are held for a minimum of seven (7) days in clean water to eliminate off-flavours. Salt (5-10 ppt) is included in the purge water to reduce stress, to prevent fungal infections and kill ectoparasites.
- Taste Test
After the purging process has been completed a taste test should be conducted on a sample from each batch of perch harvested to determine if off flavours are present. Procedures for a taste test are included in these Product Standards (Appendix 1).
- Water Quality
Potable water must be used during purging and processing. Water accessed from bores or dams may need to be further treated using UV or ozone and town water may have to be dechlorinated.
Temperature control during the killing process and holding period prior to packing or processing is essential to ensure quality and shelf life are maintained. During the killing process perch should achieve a core temperature below +5C within four (4) hours.