Plusma: modular dielectric barrier discharge (dbd) cold plasma sterilization device for inactivating escherichia coli on tomatoes and strawberries/
Ariel Jr. M. Anda, Jea B. Gorpio, John Albert L. Mariano, John Rhey T. Ugates, Rose Angeline L. Venturero, and Rigel R. Villaroman.--
- Manila: Technological University of the Philippines, 2025.
- ii, 133pages: 29cm.
Bachelor's thesis
College Of Engineering.--
Includes bibliographic references and index.
Contaminated food causes health problems. E. coli in food points to a need for better ways to sterilize. A study describes the PlusMA Cold Plasma Sterilization Device. This device uses a pulsed, high voltage plasma at 60 kilovolts DC and 50 kilohertz - it cleans E. coli from tomatoes and strawberries. Researchers bought the fruit at public markets. The device uses a Dielectric Barrier Discharge setup. Gold-plated copper electrodes are in the device. An FR4 barrier separates the electrodes. The device creates reactive particles in the air - these particles inactivate microbes without heat or chemicals. The test results showed a large drop in Colony Forming Units. Tomatoes decreased from 4,600 to 2,600 CFU per gram in four minutes. Strawberries went from 260,000 to 57,000 CFU per gram in seven minutes. Statistical analyses, including t-tests (p < 0.001) and ANOVA (F = 11.898, p = 0.008), confirmed the treatment’s effectiveness. Log-linear regression indicated a D-value of approximately 11 minutes, demonstrating a time-dependent reduction in microbial load. These findings show that cold plasma treatment effectively reduces contamination without heat or chemicals, offering a promising method for preserving the safety, physical integrity, and nutritional quality of fresh produce.
Contaminated produce Copper electrodes FR4 insulator