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A New Phytochemical Screening Programme used for Crops grown with Organic and Conventional Methods

Ravn, Dr. Helle Weber; Kristensen, Charlotte V.; Christensen, Trine F.; Diedrichsen, Brigitte and Brandt, Kirsten (2002) A New Phytochemical Screening Programme used for Crops grown with Organic and Conventional Methods. National Environmental Research Institute (NERI), Dept. of Terrestrial Ecology.

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Summary

A broad screening programme, covering the most general phytochemical groups of compounds, was developed on the basis of Thin Layer Chromatography (TLC). A total of 46 TLC systems, comprising 26 derivatization reagents, 3 stationary phases, and 4 mobile phases, were included. The TLC systems were classified according to the groups of phytochemical compounds detected: Alcohols and phenolic compounds; Carbohydrates; N-containing compounds; Organic acids and lipids; P-containing compounds; S-containing compounds, and Terpenoids. Furthermore, one group of TLC systems detected compounds from several of the mentioned groups.
The screening programme was applied in the screening of potatoes (S. tuberosum L.), peas (P. sativum L.), kale (B. oleracea L.), carrots (D. carota L.), and apples (M. domestica Borkh.), cultivated with combinations of organic and conventional methods for plant protection and nutrient supply, for phytochemical differences (biomarkers).
Distinctive phytochemical differences were found between the differently cultivated samples of these crops. In peas and carrots only one biomarker was found. In peas the biomarker was related to the soil conditions, while the biomarker in carrots was related to the use of pesticides. In potato, two biomarkers related to the use of pesticides were found. Three biomarkers were found in kale. Two of these could be related to the use of pesticide, while the last was related to either fertiliser or soil conditions. Several biomarkers were found apples, but a relation to the cultivation methods was not clear. Three of the biomarkers in apples could be related to either the use of pesticides or fertiliser, while no conclusions could be drawn from the other biomarkers found.
The results of the screening programme form the basis for a potential development of a kit to detect whether crops are organically- or conventionally cultivated. Furthermore, the results from this part and other parts of the project "Organic food and health – a multigenerational animal experiment" provide basis for the selection of which secondary compounds to quantify by specific chemical analysis, isolate, and/or structure elucidation.

Summary translation

Et bredt screeningsprogram, til detektion af de mest generelle fytokemiske stoffer, blev udarbejdet ved hjælp af tyndtlagskromatografi (TLC). I alt blev 46 TLC systemer, bestående af 26 derivatiseringsreagenser, 3 stationære faser og 4 mobile faser, medtaget i screeningsprogrammet. TLC systemerne blev inddelt i grupper alt efter hvilke fytokemiske stoffer, de detekterede: alkoholer og fenoler, sukkerstoffer, N-holdige stoffer, organiske syrer og lipider, P-holdige stoffer, S-holdige stoffer og terpenoider. En sidste gruppe af TLC systemer detekterede stoffer fra flere af de ovennævnte grupper.
Kartofler (S. tuberosum L.), ærter (P. sativum L.), grønkål (B. oleracea L.), gulerødder (D. carota L.) og æbler (M. domestica Borkh.) dyrket med kombinationer af økologiske og konventionelle metoder til plantebeskyttelse og næringstilførsel, blev screenet for fytokemiske forskelle (biomarkører) ved hjælp af det udarbejdede screeningsprogram.
Karakteristiske fytokemiske forskelle blev fundet mellem afgrøder dyrket med forskellige metoder. I prøver fra ærter og gulerod blev der fundet én biomarkør. I ærter kunne biomarkøren relateres til jordbehandlingen, mens biomarkøren i gulerødder kunne relateres til brug af sprøjtemidler. I kartoffel blev der fundet to biomarkører relateret til brugen af sprøjtemidler. Tre biomarkører blev fundet i grønkål. To af disse kunne relateres til brugen af pesticider, mens den sidste kunne relateres til enten brug af kunstgødning eller jordbehandling. En række biomarkører blev fundet i æbler, men relationen til dyrkningsmetoderne var ikke umiddelbar klar. Tre af biomarkørerne i æbler kunne relateres til enten brugen af pesticider eller kunstgødning, mens der ikke kunne drages nogen konklusion for de øvrige.
Resultaterne fra screeningen af afgrøderne danner basis for udviklingen af en simpel og billig test til at detektere, hvorvidt afgrøder er økologisk eller konventionelt dyrkede. Endvidere danner resultaterne, sammen med andre resulter fra projektet ”Økologisk kost og sundhed – et flergenerationers dyreforsøg”, baggrund for udvælgelsen af, hvilke stoffer der skal kvantificeres ved kemisk analyse, isoleres og/eller strukturopklares.

EPrint Type:Report
Keywords:thin layer chromatography, traceability
Subjects: Food systems > Food security, food quality and human health
Knowledge management > Research methodology and philosophy > Specific methods
Research affiliation: Denmark > DARCOF II (2000-2005) > III.4 (OrganicHealth) Organic food and health - a multigeneration animal experiment
Denmark > AU - Aarhus University > AU, NERI - National Environmental Research Institute
Deposited By: Brandt, Dr. Kirsten
ID Code:1490
Deposited On:02 Oct 2003
Last Modified:12 Apr 2010 07:28
Document Language:English
Status:Unpublished
Refereed:Not peer-reviewed
Additional Publishing Information:There are no plans to publish this report in any other form than in the Organic Eprints archive.

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