Feeding the sporophyll of Undaria pinnatifida kelp shortens the culture duration for the production of high-quality gonads of Mesocentrotus nudus sea urchins from a barren

Quantification of the Flavor and Taste of Gonads from the Sea Urchin Mesocentrotus nudus Using GC–MS and a Taste-Sensing System

“…Mesocentrotus nudus used in the rearing experiment are from the same area as those used in the study of Takagi et al [25]. On 1 May 2017, a total of 45 adult M. nudus (47-53 mm diameter) were collected by scuba dive from a barren (a non-commercial area where sea urchins are not highly regarded for the quality of their gonads) at depths of 2-3 m off Nojima Island in Shizugawa Bay (38 • 40 N, 141 • 30 E).…”

“…In addition, the composition of odor-active compounds in the gonads of the cultured and wild sea urchins were distinctly different [24]. More recently, Takagi et al [25] showed markedly high levels of sweet-tasting alanine and low levels of bitter-tasting arginine in the gonads of M. nudus fed with sporophylls of fresh Undaria pinnatifida and the basal frond portion of fresh S. japonica. Gonads from derived from both types of feed were evaluated as the same high-quality as those served in Tokyo sushi restaurants evaluated as two-or three-star Michelin establishments [25].…”

“…More recently, Takagi et al [25] showed markedly high levels of sweet-tasting alanine and low levels of bitter-tasting arginine in the gonads of M. nudus fed with sporophylls of fresh Undaria pinnatifida and the basal frond portion of fresh S. japonica. Gonads from derived from both types of feed were evaluated as the same high-quality as those served in Tokyo sushi restaurants evaluated as two-or three-star Michelin establishments [25]. The aim of the present study is to assess analyses of GC-MS, and GC-sniffing techniques and a taste-sensing system to provide more rigorous evaluation of gonad flavor and taste, as a contribution to providing an objective standard by which to measure the quality of sea urchin gonads.…”

“…In the present study, adult M. nudus collected from a barren were fed the basal frond portions of fresh S. japonica, the sporophylls of fresh U. pinnatifida or no food during May-July according to Takagi et al [25]. At the end of the rearing experiment, the odor-active compounds in gonads were analyzed by GC-MS and GC-sniffing techniques, and taste analysis by the taste-sensing system was conducted.…”

The Amino Acids Glutamic Acid and Alanine in Feed Increase the Alanine Content in Gonads of the Sea Urchin Mesocentrotus nudus

“…Takagi et al (2019) first succeeded in improving the gonad taste of sea urchin to a more desirable level than the gonad taste of sea urchin from a fishing ground by feeding fresh Saccharina japonica kelp to M. nudus during May-July. The gonads of M. nudus, which was collected from a barren and fed the basal frond portion of S. japonica or the sporophyll of Undaria pinnatifida kelp during May-July, reached an acceptable level for the sushi restaurants with three or two Michelin stars in Tokyo (Takagi et al, 2020a). Komata (1964) identified umamitasting glutamic acid, sweet-tasting alanine and glycine, and bitter-tasting methionine and valine as the "taste essential" amino acids in sea urchin gonads by omission test.…”