Correlations between Polyacetylene Concentrations in Carrot (Daucus carota L.) and Various Soil Parameters.

This study assessed the concentrations of three falcarinol-type polyacetylenes (falcarinol, falcarindiol, falcarindiol-3-acetate) in carrots and the correlations between these and different soil traits. A total of 144 carrot samples, from three different harvests taken a single season, were analysed in terms of their polyacetylene concentrations and root development. On one of the harvesting occasions, 48 soil samples were also taken and analysed. The chemical composition of the soil was found to influence the concentrations of falcarinol-type polyacetylenes in carrots. When the total soil potassium level was 200 mg/100 g soil, the concentration of falcarindiol (FaDOH) in the carrot samples was 630 µg/g DW, but when carrots were grown in soil with a total potassium level of 300 mg/100 g soil, the FaDOH concentration in the carrots fell to 445 µg/g DW. Carrots grown in soils generally low in available phosphorus exhibited higher levels of falcarindiol if the soil was also low in available magnesium and calcium. The concentrations of polyacetylenes in carrots were positively correlated with total soil phosphorus level, but negatively correlated with total soil potassium level. Of the three polyacetylenes analysed, FaDOH concentrations were influenced most by changes in soil chemical composition.

Influences of Biodynamic and Conventional Farming Systems on Quality of Potato (Solanum Tuberosum L.) Crops: Results from Multivariate Analyses of Two Long-Term Field Trials in Sweden.

The aim of this paper was to present results from two long term field experiments comparing potato samples from conventional farming systems with samples from biodynamic farming systems. The principal component analyses (PCA), consistently exhibited differences between potato samples from the two farming systems. According to the PCA, potato samples treated with inorganic fertilizers exhibited a variation positively related to amounts of crude protein, yield, cooking or tissue discoloration and extract decomposition. Potato samples treated according to biodynamic principles, with composted cow manure, were more positively related to traits such as Quality- and EAA-indices, dry matter content, taste quality, relative proportion of pure protein and biocrystallization value. Distinctions between years, crop rotation and cultivars used were sometimes more significant than differences between manuring systems. Grown after barley the potato crop exhibited better quality traits compared to when grown after ley in both the conventional and the biodynamic farming system.

Polyacetylenes in fresh and stored carrots (Daucus carota): relations to root morphology and sugar content.

BACKGROUND: Carrot roots contain polyacetylenes, reported to be both beneficial and distasteful when consumed by humans. This study aimed to investigate the relationships between polyacetylene contents, root morphology and sugar content in order to increase the opportunities to optimise the composition of polyacetylenes in carrots. RESULTS: The falcarinol/total polyacetylene ratio was positively correlated with root size, the amount of sucrose and the sucrose/total soluble sugar ratio among both fresh and stored samples. Root size was inversely correlated with the amounts of falcarindiol and falcarindiol-3-acetate, especially among stored samples. Stored carrots exhibited an inverse correlation between polyacetylenes and the amount of soluble sugar. At a falcarinol content at harvest below approximately 200 mg kg(-1) dry weight the amounts of all polyacetylenes increased during storage, but above that level the amounts of all polyacetylenes instead decreased. CONCLUSION: The results indicate similarities in the activity of the enzymes transforming sucrose to hexoses and the enzymes transforming falcarinol to falcarindiol-3-acetate and falcarindiol. The negative correlation between root size and polyacetylenes seems to be partly due to dilution but also to a higher synthetisation rate in smaller roots. The results indicate the existence of an equilibrium regulating the level of falcarinol.

Effects of harvesting date and storage on the amounts of polyacetylenes in carrots, Daucus carota.

The amounts of three main polyacetylenes in carrots; falcarinol, falcarindiol, and falcarindiol-3-acetate, were determined by HPLC, during three seasons, in carrots harvested several times per season and at different locations in Sweden. The amounts of falcarindiol first decreased from a relatively high level and then increased later in the harvest season. The amounts of falcarindiol-3-acetate showed similar variations, whereas the amounts of falcarinol did not exhibit any significant variation during the harvest season. During storage the amount of polyacetylenes leveled off, increasing in samples initially low and decreasing in samples initially high in polyacetylenes. The amounts of all polyacetylenes varied significantly due to external factors and between stored and fresh samples. This variation opens up possibilities to achieve a chemical composition of polyacetylenes at harvest that minimizes the risk of bitter off-taste and maximizes the positive health effects reported in connection with polyacetylenes in carrots.