Validierung: Charakterisierte Methoden für klare Fragen

Validation means to proof if a laboratory method is able to answer a question from the customer or not. For validation procedures the question has to be specific to be answered and the method has to be characterised. The growing organic market needs methods which allow the characterisation of the food. Therefore methods have to be developed which reflect the systemic approach in organic agriculture. First of all these methods shall differentiate food products grown and processed organically from those derived from other production processes. Moreover for product oriented quality control the quality criteria and their limits have to be defined within the organic market

Entwicklung der Biokristallisation für die Unterscheidung von Proben mittels computerunterstützter Texturanalyse und visueller Bildauswertung

Because of the growing market in organic produce screening methods are needed which allow the characterization of the food. Since many years the so called biocrystallization technique has been used to characterize products derived from different farming systems yet the method was not validated. The results of our investigations in the last three years show that the method can fulfill the requirements for the validation process due to international standards. The sample preparation and the crystallization procedures could be standardised and documented. For the crystallization factors of influence were described and controlled. In addition to the traditionally used visual evaluation a new computerized image texture analysis program was succesfully applied. Furthermore visual evaluation was standardized due to international norms used in sensory analysis. With a panel of trained people, crystal patterns from fresh and freeze dried carrot samples can be differentiated as statistically significant. This is a siginificant step forward because this allows the development of a structure analysis programme and will contribute to connect the different approaches within the researches in this field

Organic wheat quality from a defined Italian field-trial

Organic and conventional wheat grain (Triticum aestivum and Triticum durum) samples coming from a defined field trial in Italy were measured in 2005 and 2006 for their total protein content and the contents of lutein and zeaxanthin. Additionally the samples were analyzed by means of the biocrystallization method. The grain samples could be differentiated by the total protein content, which was higher in the conventional samples. The organic samples contained a higher lutein content in Triticum aestivum but lower in Triticum durum. Biocrystallization differentiated Triticum durum from Triticum aestivum and organic from conventional grown samples when visual evaluation was applied. Differentiation of farming systems was possible for biocrystallization evaluated with computerized texture analysis but not significant for all samples and years

Authentication of organic wheat samples from a long-term trial using biocrystallization

Organic and conventional wheat grain samples from a long-term field trial were tested with standardised biocrystallization method. In 1999-2006 the organic samples can be separated from the conventional samples using computerized texture analysis and standardised visual evaluation of the crystallization patterns. Moreover the organic samples can be classified in 2005-2006 after training in 2003