Antibacterial and antioxidant activity of ginsenosides from ginseng rootlets and their application in beef preservation
摘要
Ginseng rootlets, an underutilized by‑product of ginseng processing, are abundant in bioactive ginsenosides. This study investigated the antibacterial activity of ginsenosides derived from ginseng rootlets against four foodborne pathogens including Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhimurium, and Bacillus subtilis, and their preservative potential in minced beef. The results demonstrated that ginsenosides exerted potent, strain‑specific antibacterial activity, with the strongest effect against Escherichia coli. The inhibition zone diameter (DIZ) for Escherichia coli was 10.25 ± 0.12 mm, its minimum inhibitory concentration (MIC), was 2.85 ± 0.025 mg/mL, and its MBC was 3.3 ± 0.067 mg/mL. Besides, ginsenosides exhibited strong free radical-scavenging activity at 16 mg/mL. The scavenging rate for ABTS⁺· was 77.1%, the scavenging rate for DPPH· was 80.4%, and the scavenging rate for ·OH was 75.0%. The control group of minced beef exhibited a shelf life of 4 days, and treatments with 2% and 4% ginsenosides extended the shelf life by 2 and 4 days, respectively, compared with the control group. Ginsenosides significantly inhibited the growth of mesophilic bacteria, attenuated the increases in TBARS, acid value (AV), and pH, and effectively maintained the redness (a* value) and lightness (L* value) of beef. Consequently, ginsenosides from ginseng rootlets simultaneously suppressed microbial proliferation and oxidative deterioration, thereby extending the shelf life of minced beef. This study provided a theoretical basis for the high‑value utilization of ginseng rootlet by‑products and the development of natural dual‑functional preservatives for meat products.