夏冬两季广州菜心的硝酸盐含量及营养品质分析

Analysis of nitrate and nutrition of flowering Chinese cabbage in summer and winter in Guangzhou city

为了解广州菜心的硝酸盐含量及营养品质,分别于夏冬两季对广州4个蔬菜市场的30个菜心品种进行检测分析。结果显示,广州菜心的硝酸盐含量较高,有5个菜心品种超过国家标准,15个品种达到严重污染程度,但冬季菜心硝酸盐含量比夏季菜心低。同时,冬季菜心的外观形态和营养品质也比夏季菜心好。相关性分析显示,夏季菜心最大叶柄长与硝酸盐含量呈显著负相关,叶色与可溶性蛋白含量呈显著正相关;冬季菜心的最大叶长、最大叶宽、薹粗与硝酸盐含量呈显著负相关,叶色与维生素C、可溶性总糖和可溶性蛋白含量都有较高的相关性。因此,夏季适宜选择颜色鲜绿、叶片和叶柄长的菜心;而冬季适宜选择颜色鲜绿、叶片大和薹粗的菜心。

In order to investigate nitrate content and nutrition of flowering Chinese cabbage in Guangzhou city, in summer and winter,30 varieties of flowering Chinese cabbage collected from four vegetable markets tested and analyzed. The results showed that nitrate pollution of flowering Chinese cabbage in Guangzhou was serious. Five varieties＇ nitrate content exceeded national standard,and 15 varieties reached the serious pollution level. The nitrate content of flowering Chinese cabbage in winter was lower than in summer,meanwhile its appearance and nutritional quality were better. Correlation analysis results showed that petiole length of flowering Chinese cabbage in summer was correlated significantly and negatively with nitrate content,and leaf color was significantly positively correlated with soluble protein content. In winter,the nitrate content of flowering Chinese cabbage had significant negative correlation with maximum lead length,maximum leaf width and stem diameter,and leaf color had high correlation with vitamin C content,soluble sugar content and soluble protein content. Therefore,flowering Chinese cabbages with bright green color,long leaf and petiole in summer,or with big stalk diameter in winter,have better quality.