| 1. |
- Kjellenberg, Lars, et al.
(författare)
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Correlations between Polyacetylene Concentrations in Carrot (Daucus carota L.) and Various Soil Parameters
- 2016
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Ingår i: Foods. - : MDPI AG. - 2304-8158. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Kjellenberg, Lars, et al.
(författare)
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Effects of Harvesting Date and Storage on the Amounts of Polyacetylenes in Carrots, Daucus carota
- 2010
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 58, s. 11703-11708
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Kjellenberg, Lars, et al.
(författare)
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Influence of organic manures on carrot (Daucus carota L.) crops grown in a long-term field experiment in Sweden
- 2016
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Ingår i: Renewable Agriculture and Food Systems. - 1742-1705 .- 1742-1713. ; 31, s. 258-268
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the effects of organic agriculture manuring systems on carrot (Daucus carota) root morphology and sugar and polyacetylene content. Carrots were harvested three times per season 2006-2007 in a long-term field experiment at Skilleby research farm, Sweden. The effects of pelleted chicken manure, fresh farmyard manure and composted farmyard manure (COM) were compared against control plots left unmanured since the field experiment started in 1991. The carrots were analyzed for root size, root shape, amount of soluble sugars and amount of falcarinol-type polyacetylenes. Differences between manuring systems were found to be smaller than the variation between harvest years and harvest occasions, probably due to the grass-clover ley included in the crop rotation system. On an average for the six harvests, manuring with COM increased root length by 6% compared with fertilizing with pelleted chicken manure. Carrots fertilized with pelleted chicken manure also had 6-7% lower total soluble sugar content than carrots manured with 50 t ha(-1) of composted or fresh manure. The falcarinol to total falcarinol-type polyacetylenes ratio was 15.4% in carrots manured with 50 t ha(-1) of composted or fresh manure and 14.7% in carrots fertilized with pelleted chicken manure. Seasonal fluctuations in falcarinol-type polyacetylenes were more pronounced in carrots manured with fresh or composted manure than in carrots fertilized with pelleted chicken manure. The results suggest that manuring organic carrots with compost may be the most beneficial strategy, at least in systems where fertilizer is applied only once per crop rotation, whether directly to the carrot crop or in the preceding crop.
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| 4. |
- Kjellenberg, Lars, et al.
(författare)
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Polyacetylenes in fresh and stored carrots (Daucus carota): relations to root morphology and sugar content
- 2012
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 0022-5142 .- 1097-0010. ; 92, s. 1748-1754
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Tidskriftsartikel (refereegranskat)abstract
- 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. (C) 2011 Society of Chemical Industry
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| 5. |
- Kjellenberg, Lars
(författare)
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Polyacetylenes - in organic and biodynamic carrots
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Falcarinol type polyacetylenes (FaTP) in carrots have been assigned both positive health effects and negative effects on taste, in connection with human consumption. The aim of this thesis was to contribute to the description of factors influencing the concentrations of FaTP in carrot. Some 465 different samples, from 77 different plots, harvested at 17 different occasions during the period 2005 – 2008 were used in the investigations. The samples were analyzed concerning their size, root morphology, concentrations of soluble sugars and concentrations of polyacetylenes. Only the three major polyacetylenes in carrots; falcarinol (FaOH), falcarindiol (FaDOH) and falcarindiol-3-acetate (FaDOAc) were considered in this thesis. No single factor was found to explain all of the variation in the levels of FaTP. Factors such as harvesting year, location of growing site, length of the growing season, storage and soil conditions were shown to have a stronger impact on the FaTP concentrations than for example manuring strategy. Increased concentrations of FaDOH, and sometimes also of FaOH, appeared to be a reaction on stress, i.e. a way of resisting stress. The concentration of FaTP increased until 110-115 days after sowing and then decreased during the latter part of the season. Initially the levels of FaTP increased as the roots grew larger. However, roots heavier than 70 g exhibited lower levels of FaDOH and roots heavier than 107 g were lower also in their total concentration of FaTP. It was not possible to assign a specific root shape as an indicator of the composition of FaTP in the carrot samples. The levels of FaOH were mainly correlated to regular changes occurring during root development, but they could occasionally increase if the carrots were grown under stressful conditions. The FaDOH concentration exhibited a pattern of variation more dependent on external factors, such as annular variation and soil conditions. The concentration of FaDOAc was more dependent on factors such as the levels of hexoses and on root length or root shape. The variation in the concentration of FaOH indicated the existence of a critical level below which the synthesis of this compound was triggered. The enzymes transforming FaOH into FaDOH appeared to be active under similar conditions as the enzymes converting sucrose to hexoses.
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