Significance of N, S and Se supply for the quality of Chinese Brassica-type vegetables with special reference to glucosinolates and selenium

甘蓝属蔬菜是中国人饮食中的重要组成部分，部分是新鲜(煮熟)的，部分是经过传统或现代加工处理后食用的。在过去的几十年里，使用矿物肥和植物保护剂以及现代品种加强了生产。然而，这些措施对生物活性物质含量的影响，其中硫代葡萄糖苷(芥子油糖苷)特别重要，没有适当的文件记录。它们的含量表现出对S状态的差异化响应和对含S氨基酸(特别是烷基和烯基硫代葡萄糖苷)来源的磺酸基团的存在和氮供应的相互作用。转化产物(异硫氰酸酯、硫氰酸酯和吲哚)不仅具有典型的口感，而且具有抗癌、抗微生物和降胆固醇的作用。计划在浙江省开展甘蓝型油菜田间大面积试验。白菜(Pak Choi)和芥菜(Brassica Jiea)。除测定农艺参数外，还测定硫代葡萄糖苷的含量，以及不同诊断工具对氮素和S需要量的适宜性。此外，这些材料还受到传统(中国)和现代保存技术的影响。在通过这些方法获得的材料中，再次检查了与质量有关的成分的含量，包括硫代葡萄糖苷及其分解产物。

Cabbage vegetable (genus Brassica), which are partly consumed fresh (cooked), partly after processing using traditional or modern procedures, represent an important part of the Chinese diet. In the passed decades production was intensified using mineral fertilizers and plant protection agents as well as modern varieties. However, the effects of these measures on the contents of bioactive substances, of which the glucosinolates (mustard oil glycosides) are particular important, are not properly documented. Their content shows a differentiated response to the S status and an interaction to the N supply due to the presence of sulfone groups and the origin from S-containing amino acids (in particular alkyl and alkenylglucosinolate). The conversion products (isothiocyanates, thiocyanates and indoles) are not only responsible for the typical taste, but possess also anti-carcinogenic, anti-microbial and cholesterol-reducing effect. It is planned to set-up an extensive field experiment in Zhejiang province using Brassica campestris L. ssp. chinensis (Pak Choi) and Brassica juncea (leaf mustard). Apart from the determination of agronomical parameters the content of glucosinolates is determined, as well as the suitability of different diagnostic tools to optimise the N and S requirement. In addition the material is subjected to a traditional (Chinese) and modern preservation technique. In the material obtained in these ways the contents of quality-related constituents including glucosinolates and their breakdown products are examined again.