Processo de cura amarela do bacalhau: dinâmica de populações microbianas, indic...

• Author(s): Dias, Susana Maria Pereira
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.5/6448
• Origin: Repositório da UTL
• Subject(s): yellow cure codfish; microbiota of codfish; sensory attributes; microbial activity; yellow pigment
• Document Type: Doctoral Thesis
• Language: Portuguese
• Advisor(s): Malfeito Ferreira, Manuel; Nunes, Maria Leonor Braz de Almeida

Description

Doutoramento em Engenharia Alimentar - Instituto Superior de Agronomia It was demonstrated that yellow cure codfish involves a substantial microbial activity, contrasting with dry-salted-codfish (white-cure-codfish) which presents lower microorganisms level. The salt content decreases during the salted-raw-codfish soaking, favouring the existing microorganisms activity. The subsequent drying step benefits proteolytic, amonifing and trimethylamine producing bacteria, with a corresponding non-protein-nitrogen content increase. The biogenic amines do not represent a public health risk because of their low concentration in yellow cured product. The dominant bacteria during yellow curing belong to the genera Staphylococcus, Psychrobacter, Pseudomonas and Alcaligenes having been established a positive correlation between the content of Staphylococcus and Psychrobacter and TVB-N and N-TMA concentration. To extend the ripening time does not seem to reflect significant differences yellow cured codfish sensory attributes and only the colour attribute allow differentiating the yellow cured codfish from dry-heavy-salted codfish It was not identified the yellow pigment chemical structure but the presence of aromatic rings was confirmed, probably from phenylalanine or tyrosine, suggesting that the proteolytic microbial activity could contribute for the yellow colour biosynthesis of this kind of product.