Department of Health and Nutrition, Takasaki University of Health and Welfare, Takasaki-shi, Japan.
Faculty of Agriculture, Takasaki University of Health and Welfare, Takasaki-shi, Japan.
J Food Biochem. 2021 Dec;45(12):e13983. doi: 10.1111/jfbc.13983. Epub 2021 Nov 3.
The traditional Japanese fermented pickle, takuan-zuke, is produced via dehydration and salt-aging of the Japanese winter radish root (Raphanus sativus L.). It has been reported that γ-aminobutyric acid (GABA; antihypertensive factor) accumulates during this production. Herein, the results of the comprehensive study (metabolites, enzyme activity, and gene expression levels were investigated) on the mechanism of branched-chain amino acid (BCAA) synthesis and glucosinolate (GLS)-myrosinase system of daikon dehydration have been reported. BCAAs, GLS, and their precursors were temporarily upregulated, and the genes linked to BCAA, GLS, and isothiocyanate synthesis (BCAT4, MAM3, IPMDH1, RMB1, RMB2, and GRS1) were upregulated during daikon dehydration. BCAAs and GLS accumulated in daikon during dehydration owing to the upregulation of genes, encoding these synthases as a stress response. These results suggest that the biological response of daikon adds characteristic flavor and health functionality to takuan-zuke and helps optimize the processing parameters to produce pickles with improved health benefits. PRACTICAL APPLICATIONS: Takuan-zuke is a popular pickle in Japan, which is produced from a Japanese winter radish root (Raphanus sativus L.), commonly referred to as daikon in Japan. Takuan-zuke is produced by dehydrating daikon either by the process of salt-pressing (shio-oshi) or sun-drying (hoshi). The processes influence the variations in the nutritional value of the final product. The results reveal that both the daikon dehydration processes can be followed to generate increased amounts of health-promoting components (e.g., branched-chain amino acid and glucosinolate) in takuan-zuke.
传统的日本发酵腌菜，高菜，是通过日本白萝卜（Raphanus sativus L.）的脱水和盐老化制成的。据报道，γ-氨基丁酸（GABA；降压因子）在这个过程中积累。在此，报道了白萝卜脱水过程中支链氨基酸（BCAA）合成和芥子油苷（GLS）-黑芥子酶系统的综合研究（代谢物、酶活性和基因表达水平）的结果。支链氨基酸、GLS 及其前体暂时上调，与支链氨基酸、GLS 和异硫氰酸酯合成（BCAT4、MAM3、IPMDH1、RMB1、RMB2 和 GRS1）相关的基因在白萝卜脱水过程中上调。由于这些合成酶的基因上调，白萝卜在脱水过程中积累了支链氨基酸和 GLS，这是一种应激反应。这些结果表明，白萝卜的生物反应为高菜增添了独特的风味和健康功能，并有助于优化加工参数，生产具有更好健康效益的腌菜。
高菜是日本一种受欢迎的腌菜，由日本白萝卜（Raphanus sativus L.）制成，在日本通常称为白萝卜。高菜是通过盐压（shio-oshi）或日晒（hoshi）过程将白萝卜脱水制成的。这些过程会影响最终产品营养价值的变化。结果表明，通过盐压和日晒这两种白萝卜脱水过程都可以增加高菜中有益健康成分（如支链氨基酸和芥子油苷）的含量。
