## 3 Results
### Effect of Nanoemulsions on the Quality Characteristics of Liquid-Smoked Salmon Fillets
#### 3.5.3 Color and Texture Properties  
The color changes in the liquid-smoked salmon fillets in the different groups are shown in Table 4. Initially, there was no significant difference (\(p\) > 0.05) in the control and treatments on the \(L^{*}\), \(a^{*}\), and \(b^{*}\) values at 0 days, indicating that the NEs had no obvious effect on the color of the salmon fillets. The decrease in the \(L^{*}\) value means that the color of the fillets was darker, and the gloss was reduced. The \(L^{*}\) value of the control decreased significantly (\(p\) < 0.05) by 15.51 \(\pm\) 0.38 between 0 and 49 days; however, a slight decline in the \(L^{*}\) value was observed in the ENT-NE, CEO-NE, and CO-NE treatments by 8.43 \(\pm\) 0.28, 8.28 \(\pm\) 0.18, and 1.07 \(\pm\) 2.60 between 0 and 49 days, respectively. The results indicated that the three NEs could restrain the decreasing lightness of the fillets during storage and that CO-NE was more effective than ENT-NE and CEO-NE. Compared with the \(a^{*}\) value of 11.65 \(\pm\) 0.95 in the control, higher \(a^{*}\) values for the ENT-NE-, CEO-NE-, and CO-NE-treated fillets were observed: 15.54 \(\pm\) 1.96, 17.04 \(\pm\) 1.72, and 21.14 \(\pm\) 1.28 on the 49 th day. The results showed that NEs could help to maintain good redness and that CO-NE exhibited the best retention effect. Regarding parameter \(b^{*}\), it had no significant change across all groups, as, during the increased storage, no obvious changes in the yellownness of the fillets were revealed. In general, CO-NE was more effective than ENT-NE and CEO-NE in restraining the decreasing lightness and redness. The preventative effect might be attributed to the antibacterial and antioxidant activity of the active ingredients contained in the NE and the barrier capacity of the NE. Figure 5: Changes in TBARS (**a**) and TVB-N (**b**) values of liquid-smoked salmon fillets treated with nanoemulsions containing entercion Gr17 alone (ENT-NE), cinnamaldehyde alone (CEO-NE), entercion Gr17 and cinnamaldehyde (CO-NE) and no entercion Gr17/cinamaldehyde (Control) during storage at 4 °C for 49 days. The red dotted line means the minimal acceptable limit. Bars with no letter in common for each treatment are significantly different (\(p\) < 0.05). The results of the texture analysis are shown in Figure 6. In all groups, decreased hardness, adhesiveness, springiness, and chewiness of the salmon fillets were observed during storage. The NEs could maintain the texture of the salmon fillets to different degrees. For the hardness value, it significantly (\(p<0.05\)) decreased on the 21 st day in the control samples. Compared to the control, the hardness of the ENT-NE-, CEO-NE-, and CO-NE-treated fillets began to decrease on the 21 st, 28 th, and 42 nd day, respectively. The reduced hardness of the control, ENT-NE, CEO-NE, and CO-NE treatments were 6.30 \(\pm\) 1.30, 3.70 \(\pm\) 0.24, 4.11 \(\pm\) 1.64, and 2.45 \(\pm\) 0.92 N across the 0-49 days, respectively, confirming the protective effect of NEs regarding hardness. These data reflected that CO-NE could more effectively prevent reduced hardness. The analysis of the adhesiveness, springiness, and chewiness also produced similar results to the analysis for hardness. During the 49 days of storage, the adhesiveness, springiness, and chewiness of the control samples decreased by 0.34 \(\pm\) 0.05 mJ, 0.83 \(\pm\) 0.14 mm, and 2.03 \(\pm\) 0.16 mJ, respectively. However, the ENT-NE-, CEO-NE-, and CO-NE-treated fillets only decreased by 0.15 \(\pm\) 0.04, 0.13 \(\pm\) 0.04, and 0.03 \(\pm\) 0.01 mJ regarding adhesiveness; 0.39 \(\pm\) 0.03, 0.46 \(\pm\) 0.04, and 0.15 \(\pm\) 0.10 mm regarding springiness; and 1.51 \(\pm\) 0.14, 1.40 \(\pm\) 0.09, and 0.99 \(\pm\) 0.43 mJ regarding chewiness by the 49 th day, respectively. Therefore, ENT-NE, CEO-NE, and CO-NE could prevent adverse changes to the texture of salmon fillets, and CO-NE had better potency than ENT-NE and CEO-NE.