The effect of macroalgal and compound feeds on the sensory quality of cultivated South African abalone, Haliotis midae Linnaeus (Mollusca, Gastropoda)

Abstract

Sensory quality often determines the market value of seafood and may be affected by the feeding regime during the product’s grow-out phase, processing, the release of volatile compounds or various cultural expectations. Here, we related the abalone diet during the grow-out phase to the sensory quality of the product as a function of abalone diet and the tasters’ preference. A quantitative descriptive analysis of the flavour and texture of abalone raised on Ulva sp., kelp, a mixed diet of various macroalgae, and a formulated compound feed, as well as of wild-collected abalone, was undertaken. Raw and cooked samples of abalone meat from each of four feed categories (Ulva spp., kelp, manufactured pellets and mixed diets) and of wild-caught abalone were offered to a taste panel (comprising abalone farmers, abalone buyers and local consumers) which was asked to score each sample for 20 sensory attributes; the sensory attributes responsible for differentiating between the samples were then identified. Complex interactions among the sensory variables were identified as important drivers of the ability of panellists to distinguish between samples. For the raw samples, visual characteristics were particularly important. Conversely, taste became generally more important in the cooked samples. The experience of the tasters (e.g. producers, local consumers or buyers) also influenced how the panellists perceived the sensory quality, with the abalone buyers having a more discerning palate.