Integrative methods of product quality assessment in connection with the P-value-determination (3 examples: food preference test, sensory evaluation and self-decomposition test)

On the basis of three examples the results of P-value determinations are presented in connection with the results of integrative test methods: food preference test with laboratory rats, sensory evaluations with consumers and self-decomposition tests. In all three cases a corresponding evidence regarding the relevant data as well as the differentiating factors fertiliser and/or cultivation systems could be demonstrated. In food preference tests with laboratory rats organically grown carrots (Tarvil cultivar) and beet roots (Formanova cultivar) were significantly preferred to the respective conventionally produced variants. The determination of electro-chemical parameters of these test products was carried out by R. Krautgartner at the Institute of Fruit Growing and Horticulture, University of Agricultural Sciences in Vienna. The P-values were lower in the organic products, thus indicating better quality. Sensory tests were applied to investigate the taste of differentlyk fertilised apples (Golden Delicious cultivar). The samples originated from a field trial at the Research Institute for Fruit Growing and Viticulture in Haidegg (Styria). In this case the lower P-values (measured by H. Keppel), the preference and the application of the organic fertiliser Agrobiosol, which has a favourable effect on soil microorganisms, were in keeping as well. A series of self-decomposition tests was carried out with spinach samples (Spinnaker F1 cultivar) from a field trial in Gerasdorf near Vienna (R. Krautgartner, Institute of Fruit Growing and Horticulture, University of Agricultural Sciences in Vienna), investigating the influence of 5 different fertilisers on product quality. The ranging of the samples according to the loss of dry matter during self-decomposition corresponded with the electro-chemical ranging: lower P-values, lower dry matter loss and a longer shelf life were found in the organically fertilised samples. The here presented concurring data obtained from different integrative quality tests in connection with cultivation methods clearly indicate the advantage and the value of multiperspective research projects.