VITAMIN A FORTIFIed PEANUT BUTTER - The Official Website of ...

HPLC quantification of vitamin A
Twenty µL of eluate was injected to HPLC (Shimadzu 10AVP, Shimadzu Corp., Columbia, Md.,
U.S.A.). Separation was achieved through a reverse phase column (Purospher RP 18e, 5 µm, 15-4,
Merck, Darmstadt, Germany) equipped with column oven at 28°C and UV detector set to 326 nm. The
analysis was carried out with 92% methanol (HPLC grade, Merck, Darmstadt, Germany) as the mobile
phase at a flow rate of 1 mL/min. The concentration of retinol was calculated using the average peak
areas compared between standards and samples. Results were reported as µg RE/g.
UV spectrophotometric quantification of beta-carotene
The resulting eluate from peanut butter samples fortified with beta-carotene was analyzed for
beta-carotene using a UV Spectrophotometer (Model Lambda 20, Perkin Elmer, Norwalk, Connecticut,
U.S.A.). Absorbance of the eluate at 436 nm was compared with the standard carotene curve read at the
same wavelength and concentration of beta-carotene was calculated. Results were reported as µg ßcarotene/g.
All beta-carotene analyses were run in duplicate. Beta-carotene was converted to vitamin A
(retinol) using the equation:
µg RE/g = µg Beta-carotene/g x 0.3 µg RE/0.6 µg/g Beta-carotene
Influence of Type and Amount of Fortificant
The type and amount of vitamin A fortificant that can be used for stabilized peanut butter was
based on the vitamin A retention equivalent of not less than 1/3 of Philippine RENI (175 μg RE) for male
adults assuming 2 servings of peanut butter a day. This is the target vitamin A level in fortified foods set
by the Philippine regulatory agencies such as the Bureau of Food and Drug. It was assumed that normal
consumption of peanut butter in the Philippines was two servings per day, equivalent to 80 g based on the
serving size of 40 g/serving as indicated on the label of peanut butter available in the market. The
computation of the amount of fortificant added was based on the vitamin A level that would give 70%,
140% and 210% of Philippine RENI per 80 g of stabilized peanut butter prior to processing. The amount
of vitamin A retained equivalent to % of RENI and % vitamin A retention were computed as follows:
% of RENI for vitamin A= amount of vitamin A after processing (μg RE) x 100
525 (μg RE)
% Recovery = amount of vitamin A after processing (μg RE/g) x 100
amount of vitamin A added (μg RE/g)
Influence of Stabilizer on Vitamin A
The influence of stabilizers on the vitamin A retention using different types and level of
fortificant used was determined. Both stabilizers were added at 0.8% level based on the weight of peanut
butter. The target amount of vitamin A retained in the sample after processing is likewise 175 μg RE of
stabilized peanut butter sample.
Statistical Analysis
Statistical analysis (ANOVA and t-Test) was performed with the use of the SAS Statistical
Analysis System (SAS Institute Inc., 1990). Means were compared using Duncan’s Multiple test at P=
0.05.
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