*3.7. Free Fatty Acids*

The results of free fatty acids in sausages with substitution of pork fat with AC are listed in Table 5. Significant differences (*p* < 0.05) were observed among the samples. The highest content of fatty acids in all the samples was oleic acid, followed by palmitic acid, stearic, and linoleic acid, indicating that replacement of pork back fat by AC did not change the major fatty acids. This aspect was similar to the previous study of [32] in Toscana sausage. With the increase of AC content, palmitic acid, palmitoleic acid, oleic acid, and arachidonic acid increased by 0.72%–5.10%, 10.71%–41.67%, 1.11%–20.04%, and 2.44%–75.61% in comparison with the control, respectively. It may be due to the AC being rich in these fatty acids. The palmitoleic acid could improve hyperglycemia and hypertriglyceridemia by increasing insulin sensitivity [35] showed that oleic acid plays a role in immunomodulation, and in treating and preventing cardiovascular or autoimmune diseases, metabolic disturbances, skin injury, and cancer. Arachidonic acid plays an important role in the brain, cognitive functions, skeletal muscle, and immune systems, which could also promotes and regulates type 2 immune responses against intestinal [36]. However, the control was higher than other fatty acids in the replacement group.


**Table 5.** Free fatty acids of sausages with substitution of pork fat by *Auricularia cornea* (AC).

Notes: Values are given as mean ± standard error. Different letters in the same row indicate significant differences (*p* < 0.05). Control (0%), AC25 (25%), AC50 (50%), AC75 (75%), AC100 (100%) substitution of pork fat by AC, respectively. SFA: Saturated fatty acid; MUFA: Monounsaturated fatty acid; PUFA: Polyunsaturated fatty acid.

> Excessive intake of Saturated fatty acid (SFA) will lead to the increase of fat content and cholesterol content in the body, which may be aggravate the risk of cardiovascular and cerebrovascular diseases [2]. The sausages incorporated with AC as a fat replacer showed less (1.28%–7.45%) SFA than the control. Additionally, Monounsaturated fatty acid (MUFA) of the replacement group increased by 0.80%–17.87% in comparison with the

control. In general, AC is a healthier food that could reduce fat intake and be beneficial to human health.
