Investigation of sensory and volatile characteristics of farmed and wild barramundi (Lates calcarifer) using gas chromatography - olfactometry mass spectrometry and descriptive sensory analysis

Abstract

Australian aquacultured and wild-caught barramundi (Lates calcarifer) were obtained for sensory evaluation and analysis by gas chromatography - olfactometry (GC-O) with simultaneous mass spectrometry. Aquacultured barramundi were sourced from commercial farms representing some typical Australian production methods: above-ground recirculation tank, in-ground lined pond, and in-ground earth pond cultivation. Wild barramundi were sourced from three river-mouth sites in Northern Australia: the Gulf of Carpentaria, the Arafura Sea in the Northern Territory, and the Coral Sea, Northern Queensland. Fish were filleted, minced into a homogeneous sample, and blast frozen for subsequent cooking and sensory and volatile analysis. Barramundi mince portions were grilled using a standardized method for sensory descriptive profiling and gas chromatography - mass spectrometry - olfactometry analysis. Volatiles from grilled fish were collected using dynamic headspace, and the extracts were subjected to direct-intensity olfactometry analysis by trained assessors. More than 30 odor-active compounds were present in the barramundi extracts, mostly with the same odor-active compounds detected in both wild and aquacultured samples. On average, the perceived GC-O odor intensities of most aroma volatiles were higher in aquacultured samples. This was also reflected by instrumental data, where most volatiles were present at higher concentrations In the aquacultured samples. Additional "muddy", "earthy", and "musty" flavor notes perceived In the lined and earth pond aquacultured samples were related to the presence of 2-methyl isoborneol and geosmin in these samples. Multivariate modeling was used to relate the sensory, olfactometry, and instrumental data; overall, there was good agreement between the data sets.