## 3 Results and Discussion
### Protein Profile Analysis Using SDS-PAGE
Results showed that in non-treated samples, the storage period caused a notable reduction in the intensity of several sarcoplasmic protein bands, including phosphoryylase b, beta-enolase, aldolase, glyceraldehyde 3-phosphate dehydrogenase (GaPDh), lactate dehydrogenase (LDHh), phosphoglycerate mutase, myokinase, and triosephosphate isomerase (Tpl). This decline in band intensity was particularly pronounced after 14 days of storage, which aligns with earlier studies indicating that protein degradation in aging meat is due to post-mortem enzymatic activity and the loss of protein solubility [58, 59]. The degradation of glycolytic enzymes such as GaPDh, beta-enolase, and Tpl, which are integral to the second phase of glycolysis, is also linked to the meat tenderization process, as has been observed in beef [60, 61]. In contrast, the sarcoplasmic proteins in the treated samples exhibited greater stability throughout the storage period. Specifically, the intensity of bands corresponding to GaPDh, beta-enolase, and Tpl was significantly higher in treated samples compared to non-treated samples, even after 21 days. This suggests that the acid treatment helped mitigate the degradation of these proteins, potentially through the antimicrobial and antioxidative properties of lactic acid and ascorbic acid, which can reduce proteolytic enzyme activity and oxidative stress. The preservation of these glycolytic enzymes could play a role in slowing down the tenderization process, contributing to prolonged meat quality during storage. Another significant observation was the preservation of myoglobin in treated samples compared to non-treated ones. While myoglobin bands completely disappeared by day 21 in non-treated samples, they remained detectable, albeit at lower intensities, in treated samples. Since myoglobin is crucial for meat color, its preservation in treated samples is particularly important for maintaining a bright red color during storage, which is desirable for consumer acceptance [62]. The analysis of myofibrillar proteins further highlights the differences between non-treated and treated samples. In non-treated samples, aging led to the degradation of several key myofibrillar proteins, including \(\alpha\)-actinin, actin, troponin-\(\Gamma\) (TnT), myosin light chain-1 (MLC-1), troponin-I (TnI), and myosin light chain-2 (MLC-2). These proteins showed a marked decrease in band intensity during the storage period, with many of them disappearing by day 14 or 21. This degradation is consistent with previous studies showing the breakdown of structural proteins such as actin and myosin during aging, contributing to the tenderization process and the breakdown of muscle fiber integrity [63, 64, 65]. However, the treated samples demonstrated better preservation of these myofibrillar proteins over the 21-day storage period. Proteins such as \(\alpha\)-actinin, TnT, and MLC-1 exhibited significantly less degradation in treated samples compared to non-treated ones. In particular, TnT, which is known to degrade into multiple fragments during aging and plays a role in meat tenderization [66], remained more intact in treated samples. The treated group showed fewer degradation products for TnT, suggesting that the acid treatment helped maintain the integrity of myofibrillar proteins, likely by limiting proteolytic activity and protein denaturation. The preservation of these structural proteins, particularly TnT and \(\alpha\)-actinin, in the treated samples is indicative of reduced enzymatic activity, which could lead to improved textural properties in the treated meat over time. The stabilization of myofibrillar proteins may result in less extensive tenderization compared to non-treated samples, potentially contributing to better meat firmness and longer shelf life. The molecular weight bands at 70 kDa and 48 kDa, which increased in intensity after 14 days in non-treated samples, showed less pronounced changes in treated samples, further indicating that the acid mixture helped reduce protein degradation and maintain structural integrity.