Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions
This study was performed to clarify the enhancement of the 4-methylthio-3-butenyl isothiocyanate induced yellowing of salted radish root (takuan-zuke) by low pH during short-term salt-aging at low temperature and low salinity. We used two different methods to prepare the dehydrated daikon prior to s...
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doaj-e0c2cc7f42884b56bc8025bace5749722020-11-25T03:52:06ZengMDPI AGFoods2304-81582020-10-0191524152410.3390/foods9111524Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt ConditionsTaito Kobayashi0Kei Kumakura1Asaka Takahashi2Hiroki Matsuoka3Department of Health and Nutrition, Takasaki University of Health and Welfare, 37-1 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, JapanDepartment of Health and Nutrition, Takasaki University of Health and Welfare, 37-1 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, JapanDepartment of Nutritional Sciences, Tohto University, 4-2-7 Kamishima-cho Nishi, Fukaya-shi, Saitama 366-0052, JapanDepartment of Health and Nutrition, Takasaki University of Health and Welfare, 37-1 Nakaorui-machi, Takasaki-shi, Gunma 370-0033, JapanThis study was performed to clarify the enhancement of the 4-methylthio-3-butenyl isothiocyanate induced yellowing of salted radish root (takuan-zuke) by low pH during short-term salt-aging at low temperature and low salinity. We used two different methods to prepare the dehydrated daikon prior to salt-aging: air-drying outdoors (hoshi takuan-zuke) or salting with a stone press (shio-oshi takuan-zuke). Low salt-aging at low temperature was carried out under pH control with citrate-phosphate buffer. The yellowing of both types of takuan-zuke was accelerated below pH 5, and the color of air-dried takuan-zuke was deeper than that of salt-pressed takuan-zuke. To elucidate this phenomenon, several previously reported yellowing-related compounds were analyzed by high-performance liquid chromatography. The result showed that the production of the primary pigment, 2-[3-(2-thioxopyrrolidin-3-ylidene)methyl]-tryptophan, was low compared with that in previous reports. Therefore, we suggest that an unknown pigment was generated through a previously unreported pathway.https://www.mdpi.com/2304-8158/9/11/1524pickled vegetablesyellowing salted radish rootglucosinolate–myrosinase systemtryptophan biosynthesisisothiocyanates |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Taito Kobayashi Kei Kumakura Asaka Takahashi Hiroki Matsuoka |
spellingShingle |
Taito Kobayashi Kei Kumakura Asaka Takahashi Hiroki Matsuoka Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions Foods pickled vegetables yellowing salted radish root glucosinolate–myrosinase system tryptophan biosynthesis isothiocyanates |
author_facet |
Taito Kobayashi Kei Kumakura Asaka Takahashi Hiroki Matsuoka |
author_sort |
Taito Kobayashi |
title |
Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions |
title_short |
Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions |
title_full |
Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions |
title_fullStr |
Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions |
title_full_unstemmed |
Low pH Enhances the Glucosinolate-Mediated Yellowing of Takuan-zuke under Low Salt Conditions |
title_sort |
low ph enhances the glucosinolate-mediated yellowing of takuan-zuke under low salt conditions |
publisher |
MDPI AG |
series |
Foods |
issn |
2304-8158 |
publishDate |
2020-10-01 |
description |
This study was performed to clarify the enhancement of the 4-methylthio-3-butenyl isothiocyanate induced yellowing of salted radish root (takuan-zuke) by low pH during short-term salt-aging at low temperature and low salinity. We used two different methods to prepare the dehydrated daikon prior to salt-aging: air-drying outdoors (hoshi takuan-zuke) or salting with a stone press (shio-oshi takuan-zuke). Low salt-aging at low temperature was carried out under pH control with citrate-phosphate buffer. The yellowing of both types of takuan-zuke was accelerated below pH 5, and the color of air-dried takuan-zuke was deeper than that of salt-pressed takuan-zuke. To elucidate this phenomenon, several previously reported yellowing-related compounds were analyzed by high-performance liquid chromatography. The result showed that the production of the primary pigment, 2-[3-(2-thioxopyrrolidin-3-ylidene)methyl]-tryptophan, was low compared with that in previous reports. Therefore, we suggest that an unknown pigment was generated through a previously unreported pathway. |
topic |
pickled vegetables yellowing salted radish root glucosinolate–myrosinase system tryptophan biosynthesis isothiocyanates |
url |
https://www.mdpi.com/2304-8158/9/11/1524 |
work_keys_str_mv |
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