Effect of Passiflora Edulis Sims Peel Feed on Meat Quality of Finishing Pigs

Passiflora edulis Sims peel (Chinese name Baixiangguo, BXG) is a by-product with a high nutritional and economic value of Passiflora edulis Sims. In this study, corn was partly replaced with BXG to make feed for finishing pigs and the effects on the carcass traits, meat quality, muscle amino acid profile, and gene expression of finishing pigs were evaluated. A total of 20 healthy finishing pigs (Duroc × Landrace × Large) were randomly divided into two groups. The control group (CON) was fed the basal diet, and the experimental group (BXG) was fed a basal diet with BXG instead of 10% corn for a period of 43 d. Compared to the CON group, the carcass weight, intramuscular fat content, and marbling score were significantly increased, while the drip loss, b^* value, and shear force of the BXG group were significantly reduced (p < 0.05). Gene expression analysis showed that the mRNA expression of lipid synthesis and oxidative-type fiber related genes was significantly increased in the BXG group (p < 0.05). Proteomic research revealed that the metabolic pathways of the BXG and CON groups differed significantly. A total of 36 differentially expressed proteins were identified, mainly related to energy metabolism, fatty acid degradation, and endocrine regulation pathways. However, the contents of glutamine, glutamate, proline, and other amino acids in the BXG group were significantly reduced (p < 0.05). Overall, this study has a positive effect on improving meat quality, but the specific mechanism needs to be further explored, which offers practical guidance for the application of BXG in producing higher-quality pork and further promotes its commercial application.