Quality assessment of fresh fish by biochemical approaches

• Main Author: Leduc, François
• Other Authors: Qualité des Produits Animaux (QuaPA), Institut National de la Recherche Agronomique (INRA), Cofinancement de la Région Nord - Pas de Calais et de l ’ Anses, Université des Sciences et Technologies (Lille 1), Jean-Claude Michalski
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2011
• Subjects: analyse sensorielle; HS - SPME - GC - MS; qualité; fraicheur; composés volatils; [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition; Gadus morhua; Salmo salar
• Online Access: https://hal.inrae.fr/tel-02811367; https://hal.inrae.fr/tel-02811367/document; https://hal.inrae.fr/tel-02811367/file/50376-2011-Leduc_1.pdf

Freshness is a key parameter for assessing the quality of fish. As fish is a very sensitive matrix to spoilage, the purpose of the freshness assessment is essen tial for all professionals of the seafood industry and for official fish inspection authorities as well. Various tools and sensor ial , chemical, physical and microbiological technics have been developed to try to determine the level of spoilage but have several limitations and most of t he time characterize s rejection thresholds. The aim of the thesis is to propose a new method based on the study of volatile compounds that may ensure s to clearly and objectively determine the quality of the fish from the first stage of spoilage . Indeed , different extraction methods of volatile compounds [Static Headspace with Solid Phase Micro - Extraction (SH - SPME) and Dynamic Headspace (DH) with the system "Purge and Trap"] were used, and different analytical tools [Gas chromatography with one and two - dimensional (GC and GC - GC) coupled with Mass Spectrometry (MS) or Olfactometry (O)] were tested on various species of whole fish or fillets [Whiting ( Merlangius merlangus ), sea bass ( Dicentrarchus labrax ), gilthead seabream ( Sparus aurata ), cod ( Gadus morhua ) and salmon ( Salmo salar )] during the storage. In addition to the sensory analysis at different days of storage (1, 4, 7, 10 and 15), SH - SPME - GC - MS, DH - GC - MS - 8O and DH - GC - GC - MS - O analysis of volatile fractions of these five species have shown over 1 22 volatile compounds common to those species , which are mainly part s of aldehydes, alcohols and ketones groups . Various statistical studies based on descriptive analysis (PCA and A H C) were used to identify markers of fish quality from the first stage of spoilage (3 - methyl - 1 - butanol, 3 - methyl - butanal, dimethyl - sulfide, ethyl - acetate, 2 - ethyl - furan.) and predictive analysis (ANOVA and MLR) to produce a model that predicts an index of freshness in relation to the volatile profile of the fish La fraîcheur est un ...