Abstract: Purpose: To study the killing effect of surface discharge plasma on the osmophilic yeast Zygosaccharomyces rouxii in apple juice and its influence on the quality of apple juice. Methods: Surface discharge plasma was applied under different conditions of voltage and air flow rate. The damage caused to the cell membrane by it was observed and its influence on physicochemical indexes, color and volatile compounds of apple juice were evaluated. Results: After 30 min of plasma processing at 21 kV, the population of the osmophilic yeast in 500 mL of apple juice decreased by 5.60 logarithms, and the plasma processing caused severe cell membrane damage, leading to cell death. Surface discharge plasma processing had no significant effect on the physicochemical characteristics or volatile compounds of apple juice (P > 0.05), while the color parameters were significantly changed by it (P < 0.05). Conclusion: Surface discharge plasma had a potent bactericidal effect on the osmophilic yeast in apple juice, which will provide a theoretical basis for applying this technique to the inactivation of spoilage microorganisms in foods.

Key words: surface discharge plasma; inactivation; osmophilic yeast; apple juice