3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
Table I
Content of C vitamin in sea buckthorn cultivars and genotypes
determined by HPLC
Content of C vitamin [mg 100 g –1 ]
Cultivar or
1st run ** 2nd run ** 3rd genotype
run ** Mean
content
Aromat * 18.2 25.7 22.4 22.1
Buchlovice I * 69.7 62.7 79.3 70.6
Buchlovice III * 41.5 46.1 44.6 44.1
Hergo 32.0 24.1 27.7 27.9
Kyjevský 105.2 92.9 94.0 97.2
Leicora 158.0 137.0 136.1 143.7
Olejová 56.0 57.4 56.3 56.6
Trofimovskaja 22.4 15.2 17.3 18.3
Velkoosecký I 183.4 187.3 168.9 179.9
Velkoosecký II 167.9 166.3 168.5 167.6
Velkoosecký III 161.3 165.0 152.1 159.5
Vitaminová 98.0 91.0 103.5 97.5
* genotype
** mean value from three subsequent analyses
of the whole method including the juice preparation was
lower as expected. This show columns 2, 3 and 4 in Table I.
The yield variation in the preparation of the filtered juice is the
reason for differences in paralel determinations that exceed
repeatability of chromatographic analyses. Data summarized
in Table I evidence that the vitamin C content differes by one
order of magnitude in individual cultivar. Coulometic measurements
summarized in Table II prove this principal finding
of liquid chromatgraphy analyses Total error of analyses with
the coulometric determination of the vitamin C content is
s814
Table II
Content of C vitamin in selected sea buckthorn cultivars and
genotypes determined by direct coulometry
Cultivar or Mean content Total measurement
genotype [mg 100 g –1 ] error [%]
Buchlovice I * 60.2 21
Hergo 20.9 29
Leicora 120.4 18
Olejová 40.5 26
Trofimovskaja * 10.3 35
rougly one order of magnitude higher than total error of analyses
with the vitamin C content determined chromatographically.
Moreover, the error of the coulometric determination
increases with the decreasing vitamin C content in the filtered
juice as indicate data in Table II. This evidences that columetry
without vitamin C separation may be utilized as the final
analytical step in need however only if semiquantitative precision
of the whole method is acceptable, e.g., in preliminary
analyses. For precise analyses, liquid chromatography has to
be used as the final step.
REFEREnCES
1. Sava, C., Chirila, E., Bucurt, L.: Forest Res. 98 (2001).
2. Tang, X., Tigerstedt, M. A. P.: Sci. Hort. 88, 203
(2001).
3. Kafkas, E., Kosar, M., Türemis, n., Baser, K. H. C.:
Food Chem. 97, 732 (2006).
4. Hernández, Y., Lobo, M. G., Gonzálet, M.: Food Chem.
96, 654 (2006).