Impact of low temperature storage on active and storage forms of folate in choy sum (Brassica rapa subsp parachinensis)

O'Hare, T. J., Pyke, M., Scheelings, P., Eaglesham, G., Wong, L., Houlihan, A. and Graham, G. (2012) Impact of low temperature storage on active and storage forms of folate in choy sum (Brassica rapa subsp parachinensis). Postharvest Biology and Technology, 74 85-90. doi:10.1016/j.postharvbio.2012.06.020


Author O'Hare, T. J.
Pyke, M.
Scheelings, P.
Eaglesham, G.
Wong, L.
Houlihan, A.
Graham, G.
Total Author Count Override 7
Title Impact of low temperature storage on active and storage forms of folate in choy sum (Brassica rapa subsp parachinensis)
Formatted title
Impact of low temperature storage on active and storage forms of folate in choy sum (Brassica rapa subsp parachinensis)
Journal name Postharvest Biology and Technology   Check publisher's open access policy
ISSN 0925-5214
1873-2356
Publication date 2012-12
Sub-type Article (original research)
DOI 10.1016/j.postharvbio.2012.06.020
Volume 74
Start page 85
End page 90
Total pages 6
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2013
Language eng
Formatted abstract
Choy sum (Brassica rapa subsp. parachinensis) is a dark green leafy vegetable that contains high folate (vitamin B9) levels comparable to spinach. Folate is essential for the maintenance of human health and is obtained solely through dietary means. Analysis of the edible portion of choy sum by both microbiological assay and LC-MS/MS indicated that total folate activity remained significantly unchanged over 3 weeks storage at 4. °C. Inedible fractions consisted primarily of outer leaves, which showed signs of rotting after 14. d, and a combination of rotting and yellowing after 21. d, contributing to 20% and 40% of product removal, respectively. Following deconjugation of the folate present in choy sum to monoglutamate and diglutamate derivatives, the principal forms (vitamers) of folate detected in choy sum were 5-methyl-tetrahydrofolate and 5-formyl tetrahydrofolate, followed by tetrahydrofolate (THF), 5,10-methenyl-THF, and 10-formyl folic acid. During storage, a significant decline in 5-formyl-THF was observed, with a slight but not significant increase in the combined 5-methyl-THF derivatives. The decline in 5-formyl-THF in relation to the other folate vitamers present may indicate that 5-formyl-THF is being utilised as a folate storage reserve, being interconverted to more metabolically active forms of folate, such as 5-methyl-THF. Although folate vitamer profile changed over the storage period, total folate activity did not significantly change. From a human nutritional perspective this is important, as while particular folate vitamers (e.g. 5-methyl-THF) are necessary for maintaining vital aspects of plant metabolism, it is less important to the human diet, as humans can absorb and interconvert multiple forms of folate. The current trial indicates that it is possible to store choy sum for up to 3 weeks at 4. °C without significantly affecting total folate concentration of the edible portion.
Keyword Folate
Storage
Vitamer
Brassica
Nutrition
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
Centre for Nutrition and Food Sciences Publications
 
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