ISHS Acta Horticulturae 637: XXVI International Horticultural Congress: Advances in Vegetable Breeding
INTERACTION OF TERPENES WITH SWEET TASTE IN CARROTS (DAUCUS CAROTA L.) |
| Authors: | H.J. Rosenfeld, G. Vogt, K. Aaby, E. Olsen |
| Keywords: | Sensory evaluation, volatiles, sugar quality parameters |
| Abstract:
Carrots (cv. Panther) were grown at 9, 12, 15, 18 and 21oC and submitted to sensory and chemical analyses. Highest sugar content and bitter taste was found in roots grown at 21°C, while those grown at 9°C scored highest for sweet taste, but lowest for bitter taste. The hypothesis of terpenes interacting in the perception of sweet taste was tested. Terpenes were analysed using dynamic headspace GCMS analysis and an overview of the data by means of Principal Component Analysis is presented. The highest content of terpenes was found in carrots grown at 21°C. However, a-terpinolene, which is the most abundant terpene in carrots, showed the highest content when grown at 9°C. It is concluded that terpenes have different threshold values for bitter taste, and  -terpinolene does not contribute to the interaction of sweet taste.
Different morphological parts of the carrot root were analysed.
The upper part of the root, containing highest concentrations of sugar and terpenes, was negatively correlated with sweet taste.
The lower part of the roots had a lower total concentration of sugars and terpenes, but scored higher for sweet taste than the upper part.
However, the theory of terpenes blocking sweet taste in carrots was not supported when analysing the phloem and xylem of the roots, probably due to the low sugar content in the phloem.
Attempts were made to remove terpenes from carrots by freezing and thawing the roots.
The terpene content in frozen carrots was reduced by approximately 24%, due to rupture of cells and leakage of terpenes during thawing.
Such carrots were much sweeter than untreated ones, though the sugar content remained unchanged.
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