1Department of Food Science, Faculty of Dairy Science, Rakunogakuen University, Ebetsu, Hokkaido 069-8501, 2Laboratory of Aquatic Food Science, Department of Fisheries, Faculty of Agriculture, Kinki University, Nara 631-8505, 3Kanagawa Prefectural Environmental Agricultural Administration of Fisheries Section, Yokohama, Kanagawa 231-8588, 4Department of Electronic System Engineering, Suwa Tokyo Rika University, Toyohira, Chino, Nagano 391-0292, 5Department of Aquatic Bioscience, Graduate School of Agricultural and Life Science, The University of Tokyo, Tokyo 113-8657, Japan
Live spear squid and Japanese common squid were sedated in seawater containing 20 mM MgSO4 (Mg-SW). For sedation, seawater temperature was slowly reduced from 15 to 7°C with ice bags. After sedation, live spear squid and Japanese common squid were individually accommodated in a highly gas impermeable plastic bag with 0.6 and 1.0 L of Mg-SW, respectively, and the bags were filled with oxygen and sealed tightly. They were transported at 5°C taking about 27 h by truck. For comparison, samples quickly frozen in liquid nitrogen and instantly killed samples were also transported at -20°C and 5°C, respectively. Changes in various components were measured. Arginine phosphate and ATP contents decreased greatly by transportation in sedated Japanese common squid. There was no clear difference in sensory scores between sedated and chilled Japanese common squid. However, arginine phosphate and ATP contents did not decrease by transportation for spear squid. The mantle muscles of sedated spear squid were more transparent and had a more favorable texture than chilled or frozen samples.