Impact of roe enhancement on quality parameters in sea urchins Echinus esculentus and Strongylocentrotus droebachiensis

The present study explored roe enhancement of the sea urchins Echinus esculentus (EC) and Strongylocentrotus droebachiensis (ST), over a 12-week trial using a formulated feed. While feeding did not significantly affect somatic growth or colorimetric parameters, it enhanced gonadal development, achieving a commercially acceptable gonad index and reducing hardness and chewiness. The feeding period improved nutritional profiles, increasing essential amino acids and beneficial fatty acids, while the sensory bitterness increased due to a rise in bitter-tasting free amino acids (FAA). A 2-week starvation period at the trial's end reduced microbial counts by 1-2 log CFU/g. Inherent differences between species in colorimetric, textural and microbial parameters remained throughout the trial, with ST showing lighter, reddish, softer gonads. At the same time, EC had harder, brownish gonads, lower microbial counts, and higher chewiness. EC fed the formulated feed had increased gonads bitterness and stronger off-taste/aftertaste, likely due to higher bitter-tasting FAA levels.