Polyphosphates changes in dried salted cod (Gadus morhua) during industrial and domestic processing
Changes in added polyphosphates throughout the processing of dried salted cod in industrial environment were evaluated. As consumers purchase both dried salted cod and desalted cod, domestic and industrial desalting processes were performed. After brining, total phosphates increased to 11.6 and 16.6 g P2O5/kg in cod processed with 3 and 6% of polyphosphates, respectively. During dry-salting, total phosphates decreased in both cases to ca. 5 g P2O5/kg, suggesting that most polyphosphates were drained with the water released. Cod with polyphosphates needed 85 h extra drying time to achieve regulatory moisture levels. After desalting, total phosphates values in dry weight indicate that phosphates were not removed during this processing step. Free phosphates, and in particular triphosphate contents, were higher in cods desalted following domestic procedures, in comparison with industrial desalting. This study demonstrates that the use of polyphosphates is not recommended for the production of Portuguese dried salted cod. These additives prevent water from being removed during the drying process, increasing the costs. Moreover, in contrast to what was assumed, part of polyphosphates is retained in the final product, even after the desalting process.
KeywordsPhosphates Triphosphate Additives Seafood bacalhau
This study was supported by the National Project POLIFOSFATOS “Use of polyphosphates in the fish processing industry: control of levels and effects of processing” (PROMAR 31.03.01.FEP.0167). Authors also thank to Riberalves, S.A. (Turcifal, Portugal), a Portuguese industry of dried salted cod, by their support in the development of the trials with cod in their facilities. B. Teixeira acknowledges the Portuguese Foundation for Science and Technology (FCT), the European Social Fund (FSE) and the Ministry of Education and Science for supporting a grant (Ref. SFRH/BPD/92929/2013).
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