Understanding the impact of growing conditions on oysters: a study of their sensory and biochemical characteristics

Crassostrea gigas, the most common oyster species grown around the world, adapts to different climates, water qualities and growing technique. Its composition is known to vary according to these factors but what about its sensory properties? The objective of this study was to develop a method that would measure objectively oysters' sensory properties and demonstrate that descriptive sensory analysis can be applied to establish relationships between sensory and biochemical measurements, with a view to understanding the impact of changes in growing conditions and techniques on sensory properties. Oysters were sampled from three oyster growing areas. They were presented to a panel of assessors trained specifically to evaluate their appearance, aroma, flavour and aftertaste characteristics following an objective protocol. Proximate composition and content of fatty acids and free amino acids were measured in replicate oysters from the same batches. The panel developed a vocabulary of 12 terms that all measured significant differences between the oysters. Significant differences were also found in the composition of oysters. Relationships between compositional measurement and sensory perception were established that reflect the impact of some growing factors. Insights gained from this study could assist the oyster industry to achieve optimized growing techniques and marketing strategies.