In Table 2, retention time and resolution of peaks obtained on DB-23 column is given together with
results obtained during sample analysis. AOCS #1 standard solution
is used as a verification sample each day before the analysis
of unknown samples to ensure that the system is working properly.
The method was also successfully applied to different food
supplement samples of vegetable origin. It was used for quantitation
of a-linolenic acid in flaxseed capsules, for quantitation of
c-linolenic acid in evening primrose and borage oil and for quanti-
tation of conjugated linoleic acid (CLA) in food supplements for
better fat consumption in mussels.
Results obtained in proficiency tests provided by FAPAS are
shown in Table 3. Obtained values in our lab are acceptable since
z-scores were considered satisfactory if |z| 6 2. Result for total
trans fatty acids in test 1467 is also acceptable because assigned
value was below LOQ of our method obtained during method validation.
Results for total trans fatty acids in test 1455 were given only for information as Kernel Density Plot with peak on 0.5 g/
100 g that is in good accordance with our results.
Demand for infant formula, as an alternative to human milk, is
growing because of inability of mothers to breast feed. Therefore,
infant formula must meet the nutritional requirements of growing
infants as close as possible to avoid serious health problems for the
survival of newborn infants. Infant foods should contain a level of
omega-3 fatty acids and arachidonic acid and shouldn’t contain
trans fatty acids (Chapkin, 2000). We have analyzed samples of
baby food enriched with arachidonic acid and docosahexaenoic
acid and the results show that the sample contains 0.2% of arachidonic
acid and 0.2% of docosahexaenoic acid.
In vegetable oils fatty acids with an even carbon number are
dominant, whereas in oils and fats of animal origin with odd carbon
number FAs are present. Also, fats and oils of animal origin
contain lot of polyunsaturated fatty acids (PUFA). That makes analyzing
the fatty acid profile even more complex. In Fig. 3 our chromatograms
of extracted fat from different tuna samples are shown.