## 3 Results and Discussion
### Water Retention  
The water retention of aquatic products affects their texture, appearance and freezing stability, and is an important and significant parameter to reflect the quality of aquatic products. The reduction of water retention capacity of frozen aquatic products may be due to two reasons: first, the mechanical damage of muscle tissue structure by ice crystals and internal stresses, causing the expansion of cell gaps or cell membrane rupture, resulting in the outflow of extracellular fluid and part of the internal fluid. Second, the change of protein structure makes its water retention capacity decrease, and the water melted by ice crystals \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Time to Pass the Maximum** & **Total Freezing Time** \\
**Freezing Methods** & **Ice Crystal Generation Zone** & **(4 \({}^{\circ}\)C\(\_\)\(-\)18 \({}^{\circ}\)C (min)** \\ \hline RF (Refrigerator direct-freezing) & 165.52 \(\pm\) 20.51 a & 635.87 \(\pm\) 57.2 a \\ SF (29.3\% Saline solution impregnation freezing) & 67.5 \(\pm\) 11.20 b & 365.44 \(\pm\) 33.4 b \\ FF (Flat freezing) & 34.5 \(\pm\) 3.58 c & 295.53 \(\pm\) 31.5 c \\ TF (Tunnel type continuous freezing) & 21.8 \(\pm\) 2.77 c & 187.14 \(\pm\) 10.55 d \\ BF (Air-blast freezing) & 20.4 \(\pm\) 1.89 c & 155.0 \(\pm\) 9.43 d \\ LF (Liquid nitrogen freezing) & 1.5 \(\pm\) 0.22 d & 6.52 \(\pm\) 0.65 e \\ \hline \hline \end{tabular} The letters “a-e” indicate significant differences (\(p\) \(<\) 0.05).  
\end{table} 
Table 1: Comparison of freezing time of cuttlefish under different freezing methods. cannot be reunited with protein molecules and separated out [17]. The effect of thawing loss during freezing of cuttlefish treated with different freezing methods was shown in Figure 1A. The thawing loss of cuttlefish treated with the six freezing methods gradually increased with increasing freezing time. In the whole storage process, the thawing loss of flat frozen cuttlefish was higher than the other five groups in the whole storage cycle, which was due to the fact that the heat-conducting plate in the flat freezing would form a squeezing pressure on the cuttlefish, and the overall structure of the cuttlefish received a serious deformation from the external damage, and the damage to the muscle tissue was greater. Cooking loss and centrifugal loss are all indicators to evaluate the water holding capacity of meat products [18]. The water-holding capacity of meat directly affects the juiciness, nutrient content, tenderness and color of meat and other edible qualities, and can reflect to some extent the degree of protein denaturation by freezing. The steaming loss and centrifugal loss of fresh cuttlefish were 8.02% and 12.10%, respectively. Figure 1B,C show the effect of freezing method on the centrifugal loss and cooking loss rate of cuttlefish during frozen storage, respectively. With the increase of storage time, the steaming loss rate and centrifugal loss rate of all six freezing methods showed an increasing trend. The cooking loss rate and centrifugal loss rate of cuttlefish treated by freezing in refrigerator direct-freezing were the largest, while the water holding capacity of the TF, BF and LF groups with fast freezing speed was higher, probably because the slow freezing speed formed larger irregular ice crystals, which damaged the tissue structure of cuttlefish and led to a decrease in the water holding capacity of the fish. [PERSON] et al. [19] also showed  
Figure 1: Change in water retention of cuttlefish during storage at \(-18\)\({}^{\circ}\)C by different freezing methods. Thawing loss (**A**). Centrifugal loss (**B**). Cooking loss (**C**). Error bars show standard deviation. that the cooking losses of _s shrimp Parapeneus cannamei_ were significantly reduced after fast freezing, which is similar to the results of the present experiment.