PNL Volume 15

1983

RESEARCH REPORTS

CAROTENOID CONTENT AND PROVITAMIN A VALUES OF PEA SEEDS WITH ORANGE VS.

YELLOW COTYLEDONS

Ludwicki, J.

Swiecicki, W. K.

Agricultural Academy, Warsaw, Poland

Plant Experiment Station, Wiatrowo, Poland

Elsewhere in this volume a new seed character is described, viz.

orange cotyledons. Because the difference in color in comparison to

typical yellow seeds was very clear we decided to analyze the pigment

extracts by chromatography. Seeds of two lines, Wt 11145 (orange

cotyledons) and Wt 3527 (typical yellow cotyledons), were analyzed.

The material was ground and hydrolyzed (KOH in alcohol) prior to

extraction with hexane.

Chromatographic separation of carotenoids was done by MgO column

chromatography using hexane and 20% solution of acetone in hexane as

solvents. For the calculation of carotenoid content, tabular values of

were used, viz: B-carotene 2592, B-cryptoxanthin 2386, lutein 2550.

For determination of the provitamin value the biological activity of

S-carotene was taken as 100%, 6-cryptoxanthin as 57% and lutein as 0.

Chromatographic analysis of pigment extracts from seeds of line

Wt 3527 (yellow cotyledons) showed the presence of two carotenoid frac-

tions (Fig. 1). Their elution was possible only after using a 20%

solution of acetone in hexane. Use of less polar solvents did not cause

visible migration of the pigments. Nor did the above conditions make

possible the removal of trace levels of blue-pink pigment (probably

anthocyanin) which formed an isolated band at the top of the column.

Chromatographic separation of pigments from seeds of line Wt 11145

(orange cotyledons) revealed three bands of carotenoids (Fig. 2). The

first, most mobile fraction which did not occur in the "typical" yellow

seeds was eluted by pure hexane. Two remaining fractions of carotenoids

were comparable with line Wt 3527. Again, the band of blue-pink pigment

was observed.

Spectral investigations showed (Fig. 3) that carotenoids in seeds

of line Wt 11145 had the maximum absorption in the following wave

lengths (nm):

I fraction - 425, 450, 477

II fraction - 425, 4 46, 475

III fraction - 422, 445, 475

On the basis of spectral data the respective fractions were identified

as I - 6-carotene; II - ft-cryptoxanthin; III - lutein.

Carotenoid pigments isolated from seeds of Wt 3527 (Fig. 4) had

maximum absorption in wave lengths (run):

I fraction - 425, 4 46, 477

II fraction - 422, 4 45, 475

The above values indicate the presence of 6-cryptoxanthin and lutein.

Table 1 gives the content of carotenoids and provitamin.

Thus it appears that seeds of Wt 11145 have more than double the

amount of biologically active f.-cryptoxanthin, plus a small amount of

B-carotene, in comparison with the yellow cotyledon line. The

provitamin activity was nearly tripled. The higher content of lutein in

line Wt 11145 is not significant from a nutritional point of view.