Study of atmospheric plasma on Sitophilus oryzae and mold control of brown rice

• Main Authors: Pei-Jie Cheng, 鄭姵緁
• Other Authors: Hua-Han Chen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/74851610383603939418

碩士 === 國立澎湖科技大學 === 食品科學系碩士班 === 104 === In this study, we investigate the effects of atmospheric plasma (respectively from Positive pulse, Negative pulse, Alternating current, Positive Direct Current and Negative Direct Current) on the control of Sitophilus oryzae and mold of brown rice (Taikeng 9; TK9). Freezed brown rice returned to room temperature then added Sitophilus oryzae to culture 10 day. The brown rice was exposed to 1 minute, 3 minutes and 5 minutes of atmospheric plasma system at 7 kV. The effect of atmospheric plasma on the control of Sitophilus oryzae adults and eggs of brown rice was investigated. The result showed that the positive pulse and negative pulse destroy Sitophilus oryzae adults and eggs at 1 minute exposure, and has a significant downward trend. In the total plate count, the brown rice was preliminary exposed to 90 second of atmospheric plasma system under the same voltage (7 kV), the preliminary result showed that the positive pulse, negative pulse, and negative direct current lose the total plate count has a significant downward trend, and decreased to 6.16, 6.29, 6.36 Log (CFU/g), respectively. Further, after exposure with 180 second and 270 second, the result showed that the treatment 270 second has a significant downward trend, decreased to 6.09, 5.92, 5.00 Log (CFU/g), respectively. In the mold and yeast count, brown rice was preliminary exposed to 90 second of atmospheric plasma system under the same voltage (7 kV), the preliminary result showed that the positive pulse, negative pulse, positive direct current and negative direct current destroy the total and showed the significant downward trend, then further step discussed 8kV treatment with 270 second. The result showed that the treatment has the most significant downward, decreased to 5.00, 5.00, 5.63 and 5.00 Log (CFU/g), respectively. Finally, in regard to the germination rate and root length of brown rice, the result showed the atmospheric plasma can affect the germination rate but will not affect the root length of brown rice. Therefore, atmospheric plasma technology can be applied to brown rice processing, helping to reduce Insect pest, microbial contamination and improve storage of the rice in the future.