Concerns over polyphosphate and glazing in seafood products
Posted on November 18, 2011 by admin
Concerns over polyphosphate and glazing in seafood products
Polyphosphates – how they may affect fish quality?
Polyphosphates are legally permitted additives that are widely used to aid processing or to improve eating quality of many foods, particularly meat and fish products. The main value of polyphosphates lies in improving the retention of water by the protein in fish but their effect is mainly on the surface of the fish through an immersion treatment. Longer immersion time leads to unjustified increase in weight and the risk of flavour or texture deterioration.
Polyphosphate treatment of fish before freezing often reduces the amount of ‘thaw drip’, i.e. the liquid released when frozen fish is thawed. Whilst this isn’t necessarily a problem in good quality frozen fish, poor quality fish, when thawed, will drip more, therefore application of polyphosphates in stale fish will ultimately mask the original quality. In chilled fillets the addition of polyphosphates in high quality fillet will reduce the amount of ‘drip loss’ during processing and distribution but can also improve the dull appearance of stale fish – thus similarly masking poor quality.
Most polyphosphates added to food are broken down to single phosphate units in the stomach when the food is eaten; indeed, many are converted to single units in the food before it is eaten, for example in chill storage or during cooking. Thus it is clear that most phosphates added to food are nutritionally equivalent to the phosphates naturally present in food, and are likely to present little hazard to health. Some countries do have limits on the amount that can be added during processing and exporters must bear this in mind. This subject is under regular review both in the UK and in the EEC and it is possible that restrictions will be imposed in the future.
See related article
http://www.fao.org/wairdocs/tan/x5909E/x5909e01.htm
Fish glazing – is it misleading customers?
Glazing – the term used to describe the application of a protective coating of ice to frozen seafood products – is used during frozen or cold storage to prevent surface drying or dehydration or ‘freezer burn. There is no maximum of glaze allowed however product labelling should include a gross weight and a net glaze weight i.e. initial weight of product before glazing in order to prevent misleading customers.
See related article
http://www.seafish.org/media/Publications/FS2-05_08-Glazing.pdf
Concern over the use of polyphospahtes and excessive glazing in seafood products has recently come to the forefront. An article from SeafoodSource.com ‘Will the cheating ever stop?’ Reports that, in the near future, the use of polyphosphates to bind in water to pangasius fillets in Vietnamese processing plants will be stopped, if the country’s government passes legislation to limit the water content (including glaze) in exported products to 83%.
