Effects of Plasma-Activated Organic Acid Solutions on Listeria monocytogenes
學生姓名:
程郁琇
指導教授:
陳泰源
學 期:
113下
摘 要:
Plasma-activated water (PAW) generates reactive oxygen and nitrogen species (RONS), exhibiting strong antibacterial activity. Organic acids inhibit pathogens by lowering pH, disrupting membranes, and inhibiting enzymes. This study investigates the synergistic effects of PAW and organic acids against Listeria monocytogenes. PAW combined with organic acids significantly inhibited Listeria monocytogenes growth, with efficacy ranked as lactic acid > malic acid > citric acid > acetic acid > propionic acid. This combination reduced intracellular pH, suppressed antioxidant enzymes, and induced oxidative damage. PAW with 1% lactic acid maintained antibacterial activity at -80, -20, and 4°C. When applied to Listeria monocytogenes - inoculated mackerel, bacterial counts decreased by 4.53 log after 120 min, without affecting pH, malondialdehyde, or total volatile basic nitrogen values values, preserving food quality. Plasma-activated lactic acid (PALA) further disrupted Pseudomonas aeruginosa and Listeria monocytogenes biofilms, reducing auto-aggregation (1.10%, 17.20%), hydrophobicity (11.40%, 67.20%) and zeta potential. PALA removed 3.57 and 5.44 CFU/cm² on stainless steel and glass, respectively, and decreased their biofilm thickness. Microscopy analysis confirmed biofilm structural disruption, reactive oxygen species accumulation, and extracellular polymeric substances degradation, enhancing biofilm removal.
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