Glazing in frozen fish fillet: review of weight determination methods

Abstract

Glazing consists on water utilization, added or not of additives, on frozen fishery product surface, which forms an ice layer to protect from dehydration and lipidic oxidation during storage. But, excess of water used for glazing is actually one of the most reported problems of fraud by consumer defense organizations, and it demands search for adequate quantification methodologies. The objective of this study was to evaluate different national and international methods, commonly used to quantify the content of water from glazing in frozen fish filets. Tests using lots with known amounts of glazing, during all steps, in individually frozen filets were conducted. The methodologies used were: (1) Portaria nº 38 de 11/02/2010, do Instituto Nacional de Metrologia, Normalização e Qualidade Industrial í  INMETRO; (2) Instrução Normativa nº 25, de 02/06/2011 do Ministério da Agricultura, Pecuária e Abastecimento í  MAPA; (3) Normas for frozen fillets of Codex Alimentarius e (4) Handbook 133 do National Institute of Standards and Technology í  NIST. The results showed that the differences between the deglazing methods were not statistically significant.