MONITORING THE QUALITY OF EUROPEAN HAKE (MERLUCCIUS MERLUCCIUS L.) FILLETS AT DIFFERENT FREEZING CONDITIONS KNOWN TO INACTIVATE ANISAKIS LARVAE
KayCei Moton- Melancon1, Isabel Sanchez-Alonso2, Cristina De las Heras2, Mercedes Careche2.
1Spelman College, Atlanta, GA, 2Instituto de Ciencia y Tecnologia de Alimentos y Nutricion, Consejo Superior de Investigaciones Cientificas, Madrid, ES.
Anisakis simplex is a parasitic nematode which can accidentally infect humans that consume raw or undercooked infected fish. Freezing of fish is one of the methods that kills Anisakis larvae, but it is important to define with precision at which point the parasites are no longer infective, since a too-short treatment may lead to health problems, but a too-extensive treatment may cause quality problems and economic losses. The objective of this work was to study the quality of hake (Merluccius merluccius L.) muscle affected by freezing conditions previously found sufficient to inactivate Anisakis. Fillets were frozen at three different freezing rates up to -20 ºC in the thermal center. They were kept at this temperature and analyzed after 24 hours and 7 days. Low-field nuclear magnetic sesonance and water holding capacity were monitored as measurements of fish quality. Anisakis simplex viability of artificially infected fish treated under these freezing conditions was also evaluated. For that, pepsin digestion, ultraviolet light recovery, mobility of larvae, and agar penetration tests were monitored. Finally, a sensory triangular test was performed to test consumers’ abilities to distinguish between fresh and frozen fish. Results showed faster freezing rates maintained the quality of the fish while effectively eliminating the Anisakis. There were significant differences between fresh and frozen fish, so at least 22% of the consumers can distinguish this difference with a 95% confidence level. These results can help in refining current fishery legislation and increasing marketability of fish.