Lactic acid/tartaric acid-maltitol antibacterial activity against spoilage bacteria and prevention of yellowing and wilting in spinach and oilseed rape

The wilting and yellowing of leafy vegetables caused by spoilage bacteria resulted in serious resource wastage. This study investigated the efficacy of a combined lactic acid (LA) and tartaric acid (TA) treatment against four predominant spoilage bacteria (Erwinia persicina, Citrobacter freundii, Pseudomonas putida, and Pseudomonas punonensis) isolated from spinach and oilseed rape. Detailed analysis using Fourier-transform infrared spectroscopy, flow cytometry, scanning electron microscopy, and light microscopy revealed substantial cellular damage in the bacteria treated by LA and TA, including loss of intracellular material, and collapse of cellular morphology, as well as effective biofilm removal. Furthermore, the combination of maltitol with LA/TA preserved the color, water content, and antioxidant activity of spinach and oilseed rape with upgrading CAT and SOD activities while suppressing PPO and POD activity. In conclusion, LA/TA-maltitol effectively delayed yellowing and water loss while inhibiting rot-causing bacteria, highlighting its potential as a preservative solution for leafy greens.