High-value utilization of waste ginger stalks: Preparation, characterization and preservation application of ginger stalk essential oil

ABSTRACT Improper disposal of ginger stalks leads to resource wastage and environmental pollution. To promote the utilization of discarded ginger stalks, this study systematically investigated the extraction process, chemical composition, antibacterial activity, and potential application of ginger stalk essential oil in preserving salmon. Three essential oil fractions were obtained via supercritical CO₂ fluid extraction coupled with three‑stage gradient pressure reduction separation. Gas chromatography–ion mobility spectrometry combined with multivariate statistical analysis identified 70 volatile compounds, among which 18 were key discriminative markers. Antibacterial tests showed that the third-stage fraction was the most effective. Its minimum inhibitory concentration and minimum bactericidal concentration against common foodborne pathogens were 2.43 mg/mL and 38.97 mg/mL, respectively. Further application to salmon preservation demonstrated that essential oil treatment effectively delayed the increase in total volatile basic nitrogen during storage, inhibited microbial proliferation, slowed color deterioration and texture softening, and exhibited outstanding comprehensive preservation performance. This study provides a viable technical pathway for the resource utilization of ginger stalk waste, holding positive implications for developing natural, efficient food preservatives and promoting the green value-added transformation of agricultural by-products.