ISHS Acta Horticulturae 73: I International Symposium on Spices and Medicinal plants
THE AROMATIC COMPOUNDS OF SPICE PLANTS IN NORDIC ENVIRONMENT |
| Author: | J.E. Hardh |
| Abstract:
The influence of ecological factors of different latitudes in Finland upon the aroma compounds of spice plants was studied during the period of 1969 – 1973. The main ecological differences between 60° th and 70° th latitude are in temperature, day length and radiation. It had been shown before that the growth rate of spice plants in the north is more rapid than in South Finland until the second 10-days' period of July. The contents of sugar and vitamin C are also sometimes higher in the north. The essential oils of fennel, dill, marjoram, mint, parsley, leek, and onion were studied at Viik (60° 11'N), Rovaniemi (66° 32'N), and Muddusniemi (69° 05'N), at which places crops were grown under exactly equal edaphic conditions. The compounds were extracted by vapor destillation for 10–20 minutes, they were further extracted by ether, concentrated by evaporating the excess ether. Fractioning was done by using a Perkin Elmer F 11 gas chromatograph and Carbowax 1500 column. The owen temperature was 150°C, N as carrier gas. The size of peaks was counted in mm2 and in % of the total area of peaks, this indicating the relative amount of each compound. It can be seen that the total amounts of aromatic compounds of dill, fennel, parsley, and marjoram are often higher under field conditions than in the greenhouse (table 1), which fact is owing to the lower temperatures, particularly low night temperatures. In the north, with a growing season for outdoor cropping of 80 days only, crops with longer growth period, e.g. onion and leek, do not reach their full maturity stage, they have, therefore, less aromatic compounds than the crops in the south. In short-period crops and root crops, on the other hand, the contents of aromatic compounds is higher in the north than in South Finland (table 2); this is due to the longer days and lower temperatures in the north, which causes a higher net assimilation rate in such plants. Looking at the specific aroma compounds, the most important ones of dill (peaks 2 and 5) representing | |
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-phellandrene and carvone, are more abundant in Rovaniemi and in Muddusniemi than in the south, thus giving a markedly stronger flavour in the north.
The same is true for parsley (peaks 12, 14, 17, and 18) (table 3) regarding the compounds.
Marjoram seems to be a plant which
