Standardization and performance of a visual Gestalt evaluation of biocrystallization patterns reflecting ripening and decomposition processes in food samples

Abstract

The biocrystallization method is based on the phenomenon that additive-specific, dendritic crystallization patterns emerge when an aqueous dihydrate cupric chloride solution with additives is crystallized on a glass plate. The patterns reflect physiological processes like ripening and decomposition and are applied in differentiating food samples according to feeding regime, production system and degree of processing. The method has been used for decades in organic food quality assessment from an ontological holistic stance. The patterns are evaluated visually and by means of computerized image analysis. The present study describes the development of the visual evaluation from a morphological description of structural features towards the perception of a Gestalt, a salient, coherent ‘meaningful-whole’, which complies more closely with the pattern formation principle of the method. The methodology was standardized according to ISO-Norms 11035 and 8587 for sensory analysis of food products, adapted for use in the visual evaluation of biocrystallization patterns. Two Gestalts, ‘Ripening’ and ‘Decomposition’, reflected in biocrystallization patterns from diverse agricultural products were characterized, trained on and examined. Based on the statistical evaluation, it is concluded that the panel has become reliable and appropriate for ranking biocrystallization patterns according to the intensity of the two Gestalts. The developed level of Gestalt evaluation of biocrystallization patterns provides a basis towards qualitative interpretative judgements on the food quality of a product relating to quality concepts based on plant physiological processes.