Biochemical composition, volatile organic compounds, sensory and consumer evaluation of Pacific cupped oysters during land-based refinement

• Main Author: van Houcke, Jasper
• Other Authors: Luten, J.B., Linssen, J.P.H.
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Wageningen University 2018
• Subjects: Life Science; Pacific; Crassostrea gigas
• Online Access: https://research.wur.nl/en/publications/biochemical-composition-volatile-organic-compounds-sensory-and-co; https://doi.org/10.18174/457892

Fresh oysters are considered a delicacy in Western Europe. In the Netherlands two species are cultivated; the Pacific cupped oyster (Crassostrea gigas) and the European flat oyster (Ostrea edulis). The Pacific cupped oyster is the main product of Dutch producers with a total production of 2300 tons in 2014. In order to increase the value of the Dutch Pacific cupped oyster product innovations, such as oyster refinement are necessary. Oyster refinement is a relatively new process in the Dutch oyster sector. The refinement process usually consists of keeping live market-sized oysters in land-based systems for a period varying from one to four months in which the oysters are fed with (naturally occurring) microalgae. The main aims of this thesis were to study the impact of feed on the biochemical composition, flavor profile and sensory characteristics during the cultivation and refinement of Pacific cupped oysters. Additionally, to gain insight into Dutch consumers’ preferences, quality perception and factors influencing their evaluation of Pacific cupped oysters. The presence of identified odor- and taste active compounds present in fresh oysters has been the subject of a review (Chapter 2). The main odor- and taste active compounds found in oysters are Volatile Organic Compounds (VOC’s), Free Amino Acids (FAA), ‘5 nucleotides and bromophenols. Furthermore, the occurrence of many of these compounds has been found to be linked to the diet of the oysters. In this thesis the main focus is on VOC’s and FAA. The VOCs found in oysters (aldehydes, alcohols, ketones, alkenes, cyclenes, alkanes, cyclanes, furans, acids and aromatic compounds) originate from n-3 PUFA, n-6 PUFA, n-9 MUFA oxidation or carotenoid, amino acid or polysaccharide degradation. The VOCs are known to be odor active compounds and are linked to odor descriptors in oysters such as mushroom, grass, green, cucumber, marine, citrus and fresh. The FAA however, are known to be taste active compounds. The FAA known to have an impact on the taste profile of ...