Effects of different dormancy-inducing methods on quality of Verasper variegatus during waterless preservation and transportation

Flatfish species such as Scophthalmus maximus, Paralichthys olivaceus, and Cynoglossus semilaevis can achieve long-term survival under low-temperature anhydrous conditions. However, Verasper variegatus shows poor survival performance under single physical cold acclimation, with a maximum survival rate of only 83.33% after 24 h, which limits its long-distance transport. Thus, we investigated the effects of different dormancy-inducing methods on the nutritional and flavor quality of V. variegatus during waterless preservation and transportation, so as to identify a better preservation method. Based on cold acclimation, we applied additional methods including vitamin C immersion, anesthesia, and light exposure. Then we compared the changes in nutritional composition, flavor, and taste characteristics during 0–18 h of waterless preservation and transportation. Results show that the cold acclimation (CA) group consumed more energy to maintain physiological balance under low-temperature and hypoxic stress, leading to a pH drop to 6.63, as well as an 11.80% increase in color value, and a 21.09% increase in springiness. In the light-assisted (LI) group, color remained stable (p>0.05), total water peak area increased by 30.65%, and free amino acids related to umami and sweet taste (Such as glutamic acid and glycine) increased by 26.34%. The vitamin C (VC) group showed significant increase in pH and color difference (p<0.05), while the anesthetic (MS) group exhibited increasing trends in color difference and flavor substances, though texture parameters did not change significantly. Correlation analysis revealed extremely significant correlations texture characteristics (Springiness, gumminess, chewiness) and taste attributes (Umami, sweet, bitter) of free amino acids (p<0.01). In conclusion, light-assisted induced dormancy is a simple, safe, and residue-free method that effectively alleviates stress response and maintains high nutritional and flavor quality in V. variegatus during waterless preservation and transportation.