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对春季露地菠菜生产中常用农药毒死蜱的消解动态,以及采后清洗对菠菜毒死蜱残留及微生物数量的影响进行了研究。结果表明:春季露地菠菜毒死蜱(48%乳油)750倍液喷施,其一级消解动力学模型为C=9.5422e-0.361t,半衰期1.92d,达到GB2763—2005中叶菜类毒死蜱最大残留限量0.1mg·kg-1的理论安全间隔期为12.6d;采后用自来水、ClO25mg·kg-1、ClO210mg·kg-1、NaClO100mg·kg-1和超声波(26kHz、450W)分别清洗1min,均可减少1log的细菌总数,但ClO210mg·kg-1处理后发现仍存在270cfu·g-1大肠菌群,表明生产中即使采用消毒剂清洗菠菜,其微生物安全性仍存在不确定性;研究中还发现,生产中常用的NaClO具有减少毒死蜱残留量的作用;此外,超声波是一种很好的辅助清洗技术,有助于减少菠菜毒死蜱残留量及微生物数量。鉴于单一清洗消毒方式在保证菠菜采后食用安全方面的不确定性,今后采用两种或两种以上的联合清洗消毒技术将有助于进一步改善菠菜乃至果蔬产品的采后安全。
The digestion dynamics of chlorpyrifos, a common pesticide used in spring field spinach production, and the effects of post-harvest cleaning on the residues of chlorpyrifos and the number of microbes in spinach were studied. The results showed that the first-order digestion kinetics model was C = 9.5422e-0.361t with a half-life of 1.92 days, reaching the maximum residue limit of chlorpyrifos in middle leaves of GB2763-2005 0.1 The theoretical safety interval of mg · kg-1 was 12.6d. After cleaning with tap water, ClO25mg · kg-1, ClO210mg · kg-1, NaClO100mg · kg-1 and ultrasonic wave (26kHz, 450W) 1log total bacteria, but after the treatment of ClO210mg · kg-1, there was still 270cfu · g-1 coliform bacteria, indicating that even the production of disinfectants cleaning spinach, the microbial safety is still uncertain; the study also found that, NaClO, commonly used in production, has the effect of reducing the residual chlorpyrifos; in addition, ultrasonic is a good auxiliary cleaning technique, which helps to reduce the residual amount of chlorpyrifos and the number of microorganisms in spinach. In view of the uncertainty of the single cleaning and disinfection method in ensuring postharvest food safety of spinach, adopting two or more joint cleaning and disinfection technologies in the future will help to further improve the post-harvest safety of spinach and even fruit and vegetable products.