## 3 Results and Discussion
### Moisture, \(a_{w}\), \(pH\), and NaCl Content Analysis  
The physicochemical properties of the SM and BF muscles of both normal and spoiled hams are shown in Table 1. It was found that spoiled hams had significantly higher (\(p<0.05\)) moisture contents (49.98-56.32 g/100g) than normal hams (39.44-46.88 g/100 g) in the same muscle. This result was consistent with the finding of [PERSON] et al. [41], who found that the moisture content was significantly higher in Spanish hams with bone taint than in normal Spanish hams, indicating that higher moisture content may be one of the causes of ham spoilage. The moisture content of BF was significantly higher than that of SM in hams of the same quality grade (\(p<0.05\)), which could be due to their different parts in dry-cured ham [31]. The SM is located on the surface and is more susceptible to environmental influences, while the BF is wrapped by the SM and subcutaneous fat, rendering it less susceptible to environmental factors [31]. Consequently, the BF had a lower water loss compared to the SM. \(a_{w}\) is the state in which water exists in the system, representing the degree to which it is bound (or degree of freedom) [15]. The higher the \(a_{w}\), the lower the degree of binding [15]. In this study, the \(a_{w}\) of spoiled hams ranged from 0.87 to 0.88, while that of normal hams ranged from 0.74 to 0.75. This indicates that the degree of binding of spoiled hams is lower than that of normal hams. Previous research has shown that when \(a_{w}>0.83\), dry-cured hams are more susceptible to microbial contamination, which can lead to ham spoilage [42]. Therefore, controlling \(a_{w}\) during the processing of ham can effectively inhibit the growth of most microorganisms [15]. [PERSON] et al. [43] demonstrated that \(a_{w}\) decreased with the  
Figure 1: Sensory evaluation of different muscles in normal and spoiled hams. Different uppercase letters (A,B) indicate significant differences between hams with different quality grades for the same muscle (\(p<0.05\)), and different lowercase letters (a,b) indicate significant differences between different muscles for the ham with the same quality grade (\(p<0.05\)). N–SM: normal ham–semimembranosus; N–BF: normal ham–biceps femoris; S–SM: spoiled ham–semimembranosus; S–BF: spoiled ham–biceps femoris. increasing ripening time of the Laowo ham. The \(a_{\text{w}}\) of Laowo ham reached 0.74 after undergoing a 9-month maturation period, which exhibited similarity to the results of normal Xuanwei ham ripened for one year in this study. The pH of the spoiled hams ranged from 6.45 to 6.64, whereas the pH of the normal hams ranged from 5.74 to 5.79. These results are similar to the findings of [PERSON] et al. (2015) in Manning hams, who found the pH of normal ham was approximately 5.93, whereas that of deeply spoiled ham was around 6.51. According to [PERSON] et al. (2014), microorganisms were more suitable for colonisation on dry-cured hams when pH > 6.0, indicating that spoiled hams were more susceptible to microbial influences. The salting process of Xuanwei ham involved four stages: first at 4%, then at 3%, then at 2.0% and finally at 1.0%. Conducting salting in multiple stages facilitated salt penetration, while the subsequent drying process caused significant water loss from the ham, leading to an increase in salt concentration ([PERSON] et al., 2016). The NaCl content in normal hams was significantly higher (\(p<0.05\)) compared to that in spoiled hams in the same muscle, which may be related to salt penetration during the curing and the rate of air drying ([PERSON] et al., 2016). The lower the salt content, the greater the water retention capacity of the ham, resulting in the higher moisture content observed in spoiled hams. Additionally, [PERSON] et al. (2015) found that a low salt content could result in an increase in pH, which was consistent with the pH results. For hams with the same quality grade, the salt content of the BF was significantly higher than that of the SM (\(p<0.05\)).