The second main class of folates derivatives was formyl derivatives.
10-HCO-PteGlu and 5-HCO-H4folate represented 6% to 16% in
spinach and 7% to 12% in green beans respectively. 5-HCO-H4folate
residual ratios (C1/C0) increased with the temperature increase
both in spinach and green beans between pH 7 and pH 5. 10-
HCO-PteGlu residual ratios (C1/C0) were quite stable at 25 C both
at pH 7 and 5 while it increased with rising temperature both at pH
7 and 5.