Overview: Folic acid is a water-soluble vitamin, named for its abundance in green leaves, also known as pteroylglutamic acid. It exists in several forms in nature, with its parent compound composed of pteridine, para-aminobenzoic acid, and glutamic acid. Folic acid plays a crucial role in protein synthesis, cell division, and growth, and promotes the formation of normal red blood cells. This kit uses a microbiological method to detect the total amount of folic acid (added and natural) in infant formula. After incubation at 37°C in the dark for 23–24 hours, the turbidity of the samples is measured at 620–630 nm using a microplate reader. By comparing the sample turbidity with a standard curve, the folic acid content in the sample can be quantitatively determined.

Principle: Folic acid is an essential nutrient for the growth of Lactobacillus rhamnosus. The culture medium and processed sample extract are added to microplate wells coated with the bacterial strain. After incubation for a period, the absorbance is measured. Within a certain detection range, the folic acid content in the sample extract can be calculated based on the standard curve of folic acid concentration versus absorbance.