Abstract:
Vitamin A is fortified to dairy products, such as milk, cheese, and ice-cream, infant
formulas and many other foods in the form of Retinol or Retinyl Ester and it is important
to quantify the amount of vitamin A content in food products because both high intake
and low intake of vitamin A causes certain malfunctions in human body. Considering
high intake of vitamin A, it may causes transient and disappear, increase the breakdown
of our bones, fetal resorption; abortion, birth defects and permanent learning disabilities
in the progancy and ect. Low intake if vitamin A can cause fetus resorption, night
blindness, loss in the immune response and ect.
Quantification of vitamin A from infant formulas is difficult as it is in minute
amount in infants, due to presence of isomers of vitamin A and it’s sensitivity to light,
air, heat. When extracted from infants or any other food vitamin A tends to degradate in
to stable products. So it must be carefully extracted.
We developed a method to quantify the vitamin A content in infant formulas. Major
steps involved in the method were saponification, extraction, concentrating, and analysis.
Saponification was done using Ethanolic KOH solution and it was extracted to Petether
solution, concentrated using both rotary evaporator and Nitrogen flow, and finally
analyzed using reversed phase HPLC, using 95% Methanol as mobile phase, at a flow
rate of 2 ml/min and the UV-detector at 325nm was used to calculate the peak area. The
purity of standard was calculated using maximum UV absorbance at 324-328 nm range.
Concentrations of vitamin A in samples were calculated using calibration curve drawn for
standard solutions using Minitab software. Four samples were analyzed and two samples showed higher levels of vitamin A compare to that indicated on the label and two samples showed low amount than indicated on the label. Vitamin D is also a fat-soluble
vitamin and it is important to develop a method to determine vitamin D content also.
