Influence of processing on total, monoglutamate and polyglutamate folate contents of leeks, cauliflower, and green beans.
Bioavailability of dietary folate might be impaired by the polyglutamate chain to which approximately 70% of dietary folates are bound. This chain must be removed enzymatically in the intestine before folate is absorbed as a monoglutamate. To increase formation of monoglutamate folate in vegetables, the vegetables were subjected to various processing treatments. Treatments included freezing (-18 degrees C, 16 h) and thawing (4 degrees C, 24 h) and hydrostatic high-pressure treatment (200 MPa, 5 min). Both freezing/thawing and high-pressure treatment increased the proportion of folate in the monoglutamate form in leeks, cauliflower, and green beans 2-3-fold. However, loss of total folate after these treatments was >55%. It is concluded that conversion of folate polyglutamate to the monoglutamate form in vegetables is possible by certain processing treatments. Potentially this could lead to vegetables with higher folate bioavailability. However, to prevent folate loss into processing water, processing in a closed system should be applied.
Melse-Boonstra
Alida
A
Division of Human Nutrition and Epidemiology, Wageningen University, P.O. Box 8129, 6700 EV, Wageningen, The Netherlands.
Verhoef
Petra
P
Konings
Erik J M
EJ
Van Dusseldorp
Marijke
M
Matser
Ariette
A
Hollman
Peter C H
PC
Meyboom
Saskia
S
Kok
Frans J
FJ
West
Clive E
CE
D001682:Biological Availability; D001937:Brassica / Q000737:chemistry*; D007887:Fabaceae / Q000737:chemistry*; D005511:Food Handling; D005615:Freezing; D005971:Glutamates / Q000032:analysis*; D006358:Hot Temperature; D006874:Hydrostatic Pressure; D019697:Onions / Q000737:chemistry*; D011624:Pteroylpolyglutamic Acids / Q000032:analysis* / Q000493:pharmacokinetics
D005971:Glutamates; D011624:Pteroylpolyglutamic Acids