Tan Jing Ni, Hwang Cheng-An, Huang Lihan, Wu Vivian C H, Hsiao Hsin-I
Department of Food Science, National Taiwan Ocean University, 2 Beining Road, Jhongjheng District, Keelung City 202, Taiwan.
Residue Chemistry and Predictive Microbiology Research Unit, Eastern Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA.
J Food Prot. 2020 Feb 1;83(2):287-294. doi: 10.4315/0362-028X.JFP-19-434.
In situ generation of chlorine dioxide to reduce microbial populations on produce surfaces has been shown to be effective on produce models. This study examined the treatment for decontamination of bacterial pathogens on whole cantaloupes and sprout seeds. Whole cantaloupes, mung beans, and alfalfa seeds were inoculated with Salmonella, Listeria monocytogenes, and Shiga toxin-producing Escherichia coli, sprayed with or dipped in 0.4 to 1.6% sodium chlorite (NaClO2) solutions, dried, and treated with 6 mM hydrochloric acid (HCl; sequential treatment). Controls were samples treated with NaClO2 or HCl (individual treatment). The pathogen populations on samples before and after treatments were enumerated to determine the reductions of pathogen populations by the treatments. The methods of applying NaClO2 and HCl (dipping for 30 min or spraying 0.2 g on cantaloupe rind [2 by 2 cm]), NaClO2 concentrations of 0.4 to 1.6% for cantaloupes, and treatment times of 5, 15, and 30 min for sprout seeds were evaluated to identify treatment parameters. For cantaloupes treated with spraying with 1.6% NaClO2, the sequential treatment caused significantly (P < 0.05) higher reductions (6.2 to 7.7 log CFU/cm2) than the combined reductions (3.2 to 5.2 log CFU/cm2) by the individual treatments. For cantaloupes treated by dipping in 1.6% NaClO2 and by spraying with 0.4 and 0.8% NaClO2, the reductions caused by the sequential treatment were not significantly (P > 0.05) different from those by the individual treatments. For mung beans, sequential 15- and 30-min treatments caused significantly (P < 0.05) higher reductions of 4.3 to 5.0 and 4.7 to 6.7 log CFU/g, respectively, than the individual treatments. The sequential 15-min treatment also caused high reductions of 5.1 to 7.3 log CFU/g on alfalfa seeds. The treatments did not bleach the color of cantaloupes and did not affect the germination rates of mung beans and alfalfa seeds. This study identified 1.6% NaClO2 and 6 mM HCl for sequential spraying treatment for cantaloupes and for sequential dipping (15-min) treatment for mung beans and alfalfa seeds that may be used for decontamination of whole cantaloupes and sprout seeds.
已证明在农产品表面原位生成二氧化氯以减少微生物数量在农产品模型上是有效的。本研究考察了对完整哈密瓜和豆芽种子上细菌病原体的去污处理。将完整的哈密瓜、绿豆和苜蓿种子接种沙门氏菌、单核细胞增生李斯特菌和产志贺毒素大肠杆菌，喷洒或浸泡在0.4%至1.6%的亚氯酸钠（NaClO₂）溶液中，干燥后，用6 mM盐酸（HCl；顺序处理）处理。对照组为用NaClO₂或HCl处理的样品（单独处理）。对处理前后样品上的病原体数量进行计数，以确定处理对病原体数量的减少情况。评估了应用NaClO₂和HCl的方法（浸泡30分钟或在哈密瓜表皮[2×2厘米]上喷洒0.2克）、哈密瓜的NaClO₂浓度为0.4%至1.6%以及豆芽种子的处理时间为5、15和30分钟，以确定处理参数。对于用1.6% NaClO₂喷洒处理的哈密瓜，顺序处理导致的减少量（6.2至7.7 log CFU/cm²）显著（P < 0.05）高于单独处理的综合减少量（3.2至5.2 log CFU/cm²）。对于用1.6% NaClO₂浸泡处理以及用0.4%和0.8% NaClO₂喷洒处理的哈密瓜，顺序处理导致的减少量与单独处理的减少量无显著（P > 0.05）差异。对于绿豆，15分钟和30分钟的顺序处理分别导致的减少量显著（P < 0.05）高于单独处理，分别为4.3至5.0 log CFU/g和4.7至6.7 log CFU/g。15分钟的顺序处理对苜蓿种子也导致了5.1至7.3 log CFU/g的高减少量。这些处理没有使哈密瓜变色，也没有影响绿豆和苜蓿种子的发芽率。本研究确定了1.6% NaClO₂和6 mM HCl用于哈密瓜的顺序喷洒处理以及绿豆和苜蓿种子的顺序浸泡（15分钟）处理，可用于完整哈密瓜和豆芽种子的去污处理。
