Systematic review of the odorous volatile compounds that contribute to flavour profiles of aquatic animals

Abstract

The flavour of aquatic animal products is distinct from terrestrial foods, facilitating a competitive marketing advantage. However, the flavour of aquatic animals can also be highly variable. Importantly, differences are reported in the flavour of animals from aquaculture and wild‐capture systems. These differences can erode consumer acceptance of aquaculture products and reduce financial returns to producers. Mild ‘fish‐like’, ‘marine’, ‘crustacean‐like’, ‘seafood’ and ‘sweet’ odours are desirable. However, overt ‘fish‐like’, ‘fatty’ and ‘earthy’ odours are quality deficits and cause products to become unpalatable. Odorous volatile compounds are responsible for eliciting these characteristic odours. In this literature review, the odorous volatile compounds of 96 aquatic animal samples are reported, revealing 291 different compounds. Generalist compounds that are integral to the odour of aquatic animals are presented in addition to 86 compounds that elicit key characteristic odours. The influence of these compounds on aquatic animal flavour is explored and the specific factors likely to affect their manipulation in aquaculture products are discussed. The culture environment and diet are critical factors affecting volatile profiles of aquatic animals and are the variables that can be controlled by aquaculture producers. The information presented in this review can underpin the development of innovative aquaculture strategies that prevent environmental exposure of aquatic animals to unpalatable volatile compounds and facilitate the development of aquaculture diets that optimise the volatile profile of edible tissues.

Comparative Evaluation of Wild and Farmed Rainbow Trout Fish Based on Representative Chemosensory and Microbial Indicators of Their Habitats

“…In our opinion, this was mostly true in the case of the fishy attribute, which increased from 1.6 in B-I to 4.41 points in B-P. Furthermore, fishy together with the musty and mushroom-like attributes might potentially mask the perception of attributes like sweet and green/grassy. , …”

“…The universal earthy/musty off-flavors geosmin and 2-methylisoborneol (MIB) were also detected. Additionally, other nine compounds with earthy and/or musty off-notes were detected, suggesting that earthy and musty malodors are not solely caused by geosmin and MIB. ,,,,− …”

“…Furthermore, fishy together with the musty and mushroom-like attributes might potentially mask the perception of attributes like sweet and green/ grassy. 31,32 Among the fish samples, wild fish was significantly different from farmed fish samples and presented higher ratings of sweet, fruity, and citrus-like aroma impressions compared to farmed fish. On the other hand, there was a lower rating of metallic, musty, earthy, and muddy off-flavor notes.…”

“…15 This assumption is supported by additional studies that have discussed feeds as sources for malodors in fish. 31,36 Further, 4-ethyloctanoic acid was reported as likely a contaminant of animal origin. 5,6 However, both boar taint-like odors skatole and androstenone were not detected in the current samples that were fetched in spring, even though they were highly pronounced in the samples collected in summer.…”

“…Thereby, odorants with high octanol/water partition coefficient (log K OW ) have been shown with higher accumulation rates from water into fish. 31 This phenomenon is particularly important when it comes to malodors. In this context, the study of Johnsen and Lloyd showed that fish meat with a fat content of 2.5% accumulated three times more MIB (log K OW ∼ 2.93) than fish with <2% fat.…”