田间施用硝化抑制剂DMPP对小青菜贮藏过程中硝酸盐与Vc含量的影响

Effects of Nitrification Inhibitor DMPP(3,4-Dimethylpyrazole Phosphate) on Nitrate and Vitamin C(Vc) Concentrations in Greengrocery (Brassica campestris L . ssp. chinensis) During Storage

采用田间施药方法,研究了施用硝化抑制剂3,4-二甲基吡唑磷酸盐(3,4-dimethylpyrazolephosphate,DMPP)对冰箱贮藏条件下小青菜可食部分硝酸盐、维生素C(Vc)含量变化的影响。结果表明,在贮藏过程中,施与不施DMPP2种处理小青菜硝酸盐含量呈现先降低后略有升高的趋势,Vc含量呈降低的趋势;DMPP在贮藏前期能够有效地降低硝酸盐含量,延缓Vc含量的降低。贮藏2d后,DMPP处理小青菜硝酸盐、Vc含量分别降低了74.4和9mg·kg-1,而对照处理分别降低了54.4和50mg·kg-1,处理间硝酸盐、Vc降幅差异均达5%显著水平。贮藏2～4d中,DMPP处理硝酸盐、Vc含量分别降低了20.1和91mg·kg-1,而对照处理分别降低了144.7和84mg·kg-1,处理间硝酸盐含量降幅差异达5%显著水平。贮藏4～6d中,对照处理硝酸盐含量升高了60.6mg·kg-1,DMPP处理升高了76.2mg·kg-1,Vc含量分别降低23和117mg·kg-1,且处理间降幅差异达5%显著水平。蔬菜贮藏时间不要过长,以不超过4d为宜。

The influence of nitrification inhibitor (NI) 3,4-dimethylpyrazol e phosphate (DMPP) applied in the field on nitrate and vitamin C (Vc) concentratio n in the edible part of greengrocery (Brassica campestris L. ssp. chinensis) was investigated during the course of storage with refrigerator in the experiment. Results indicated that there was a tendency that nitrate concentration reduced i n the prophase, then slightly increased in the anaphase and Vc concentration red uced in the course of storage of greengrocery whether it treated with DMPP or no t. In the prophase of storage nitrate concentration in greengrocery treated with DMPP could be effectively reduced but Vc concentration maintained a high level. After two days storage, nitrate concentration in greengrocery treated with DMPP reduced 74.4 mg·kg-1,while nitrate concentration in greengrocery without DMP P reduced 54.4 mg·kg-1, and the difference of nitrate concentration decreasing between treatments reached 5%significant level; meanwhile, Vc concentration fo r ASN+DMPP and ASN treatment reduced 9 mg·kg-1 and 50 mg·kg-1 respectively, and the difference reached 5%significant level.During 2～4 days storage,nitrat e concentration in greengrocery treated with DMPP or without DMPP reduced 20.1 m g·kg-1 and 144.7 mg·kg-1 respectively, and there was 5%significant differen ce; whereas Vc concentration reduced 91 mg·kg-1 and 84 mg·kg-1 respectively. During 4～6 days storage, nitrate concentration in greengrocery treated with DM PP or not increased 76.2 mg·kg-1 and 60.6 mg·kg-1 respectively, but there wa s no significant difference; whereas Vc concentration reduced 117 mg·kg-1 and 23 mg·kg-1 respectively, and there was 5%significant difference. Thus, it was recommended that the time of storage of greengrocery should not be longer than four days.