Non-thermal Atmospheric Gas Plasma Device for Surface Decontamination of Blueberry

• Main Authors: FENG, HSING-HUA, 馮性樺
• Other Authors: HSU, CHUAN-LIANG
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/gq35ep

碩士 === 東海大學 === 食品科學系 === 106 === Non-thermal atmospheric pressure gas plasma is increasingly under research for decontamination of foods, especially for fresh fruits and vegetables. Fresh blueberry, often used in baking and pastry food ingredients, which is susceptible to soil and water as well as fertilizer contamination caused by Escherichia coli (E. coli.) and Salmonella spp. during the time of planting. General cleaning process after the harvest unable to effectively reduce pathogen contamination for blueberry, while the traditional thermal processing sterilization methods make blueberry tissue soften due to heat and lead to the loss of nutrients. This study aims to apply a non-thermal atmospheric gas plasma device for surface decontamination of blueberry. The process parameters applied were frequency at 60 Hz, input power 40 W, voltage at 21 kV, electrode spacing 0.5 cm, using air as working gas (500 sccm), plasma exposure time for 0, 1, 4, 7, 10 and 15 min. The influences of plasma treatment on blueberry were evaluated through bacteria count, surface temperature, weight loss, texture, and color change. Experimental results show that after 15 min plasma treatment, E. coli with initial concentration of 7.6 log CFU/ml on the surface of blueberry can be completely decontaminated. Salmonella spp with initial concentration of 7.1 log CFU/ml on the surface of blueberry reduced from 7.1 log CFU/ml to 0.9 CFU/ml The qualities of the blueberry are not significantly changed after the plasma treatment. The results implicated that non-thermal atmospheric pressure gas plasma could be employed for decontamination of blueberry while retaining product quality.