【作者】 袁丽红；

【导师】 朱建雯；

【作者基本信息】 新疆农业大学 ， 环境科学， 2008， 硕士

【摘要】 通过水培方式,研究氮水平对不同叶菜硝酸盐含量的影响及N、P、K肥配施对叶菜硝酸盐含量的影响,另外还研究了贮藏和烹饪手段下叶菜的硝酸盐累积特征。为乌市叶菜安全生产提供理论依据,同时也为民众叶菜的安全食用方式提供理论参考。主要的研究结果如下:1、不同氮水平处理下3种叶菜植株中的硝酸盐含量为小白菜﹥生菜﹥菠菜。3种叶菜不同器官中的硝酸盐含量,小白菜为:叶柄(茎)﹥叶片﹥根;菠菜表现为:根﹥叶柄﹥叶片;生菜在氮浓度≤15mmol/L时,表现为:叶柄﹥根﹥叶片,在氮浓度≥20mmol/L时,表现为:叶柄、根﹥叶片。2、4种小白菜的生物量均随着氮浓度的增加而增加。4个品种小白菜植株硝酸盐含量表现为:上海青>四月慢>黑油白菜>五月慢。不同品种的小白菜的各个器官的硝酸盐含量不同,叶片、叶柄均为:上海青>四月慢>黑油白菜>五月慢,根部为:四月慢>五月慢>上海青>黑油白菜。随着氮浓度的增加,硝酸还原酶活性呈增加趋势,但小白菜品种间的硝酸还原酶活性差异不显著。3、2种生菜的生物量随着氮浓度的增加而增加,且生物量在氮水平间差异较小。2种生菜体内硝酸盐含量随氮浓度的增加而增加。在不同的氮处理下2种生菜叶柄的硝酸盐含量有明显的差异,2种生菜根部的硝酸盐含量均高于叶柄及叶片。培养液中的硝态氮浓度降幅依次为:N4>N1>N3>N2。2种生菜的硝酸还原酶活性存在差异。4、N、P、K肥配施处理下,小白菜中的硝酸盐含量存在显著差异,培养液中N:P2O5:K2O为1:0.5:1.25时小白菜中的硝酸盐含量较高,达到1824.86mg/kg。小白菜器官中硝酸盐含量表现为:叶柄(茎)﹥叶片﹥根。小白菜中硝酸盐含量随处理时间的增加而增加,呈现持续增加的趋势。5、在室温和冷藏下,新鲜叶菜和漂烫后小白菜中的硝酸盐含量随着贮藏时间的增加而减少,48h降低16.76-79.16%。小白菜经冷藏处理后的硝酸盐含量要比室温存放的高21.77-234.5%。经油炒烹饪的小白菜硝酸盐含量可减少51.58%,亚硝酸盐含量增加391%,小白菜中亚硝酸盐含量与氮处理水平呈正相关。更多还原

【Abstract】 This paper reached the characteristics of the nitrate content of different type’s leafy vegetables which were hydroponics cultivated under different nitrogen level and equilibrium fertilizer (N, P, and K) as well as reached the characteristics of nitrate accumulation of leafy vegetable under storage and cooking. It offers theory basis for leafy vegetables safe production and theory references for safe consuming of leafy vegetables. The main conclusions were as follows:1 The nitrate content of three leafy vegetables under different nitrogen level was: Chinese cabbage> Spinach> lettuce. Chinese cabbage nitrate content showed that: petiole (stem)> leaves> root; Spinach nitrate content showed that: root> petiole> leaves. When lettuce nitrogen concentrations≤15mmol/L, nitrate content showed that: petiole> Root> leaves; When nitrogen concentrations≥20mmol/L, nitrate content showed that: petiole, root> leaves.2 With the increase of nitrogen concentration, the biomass of four varieties of Chinese cabbage have increased. The nitrate content of four varieties of Chinese cabbage showed that: shanghaiqing> Siyueman> Heiyoubaicai> Wuyueman. The nitrate content of various organs had difference in the different varieties of Chinese cabbage. The nitrate content of leaves and petioles are showed that: Shanghaiqing> Siyueman> Heiyoubaicai> Wuyueman. The nitrate content of root showed that: Siyueman > Wuyueman > Shanghaiqing > Heiyoubaicai. The nitrate reductive activity (NRA) was growing with the increase of nitrogen concentration of Chinese cabbage, but tow Chinese cabbage, NRA has no significant difference.3 The biomass of two kinds of lettuce was increasing with the nitrogen increased. The biomass between the different nitrogen concentrations had a little difference. The nitrate content of two kinds of lettuce increased with the concentration of nitrogen increased. The nitrate content of Lettuce petiole had obvious differences in the different nitrogen treatment. Nitrate content of lettuce roots were all higher in different nitrogen concentration. The nitrate concentration of Hydroponics was: N4> N1> N3> N2. The nitrate reductive activity of two kinds of lettuce has difference.4 The nitrate content of Chinese cabbage was significantly different under equilibrium fertilization treatment. When nutrient share of Hydroponics of N: P2O5: K2O for 1:0.5:1.25, The nitrate content of Chinese cabbage reached the highest value 1824.86mg/kg. The nitrate content of Chinese cabbage organ was: petiole (stem)> leaves> root. The nitrate content of Chinese cabbage increased as treatment time increased which showing a gradually increasing trend.5 Under room and refrigerate temperature, nitrate content reduced as storage time extended in the fresh and blanching of Chinese cabbage. The nitrate content reduced 16.76-79.16% after 48 hours. The nitrate content of Chinese cabbage refrigerated was higher 21.77-234.5% than that of room temperature storage. Under cooking treatment, the nitrate content of Chinese cabbage reduced about 51.58%, but nitrite content increased 391%. The nitrite content of Chinese cabbage had positive correlation with the nitrogen concentration.更多还原