Copper chloride crystallization

Copper-chloride crystallization, inter alia, for carrots has been in-house validated and standardised within the framework of the BÖL-projects 02OE170 und 02OE170F [1]. The method shows specific dendritic crystallization patterns for different plant extracts that crystallize together with an aqueous copper chloride dihydrate solution on a glass plate [2] [3] [4] [5] [6] [7] [8]. The spontaneous crystallization in the form of needles occurs when the saturation limit of the salt solution is exceeded during the phase of evaporation of the liquid [9] [10] [11]. This takes place under standardized conditions that are recorded for each sample with the help of a laboratory documentation program (LabDoc). In addition to the visual evaluation [12] [13], the resulting images can also be evaluated with a computer-aided texture and structure analysis [14] [15].

So far, thousands of samples of cultivation trials / varieties have been examined [6] [5] [3] [7] [16]. First tests show that the method is also, or possibly especially, used to investigate the influence of processing on the food (see studies on milk [3] [4] and carrot baby food [17]), as well as in connection with Sample and marker substance [10] [11] (elucidation of the mechanism of action of the method). The visual evaluation of the crystal images is carried out by a panel of trained people. [12]

To elucidate the mechanism of action ‘of the method, pectin [18] is used as a marker in preliminary experiments; this polysaccharide is part of the carrot [19] [20] [21]. It is believed that on the one hand it modulates the effect of secondary ingredients in the carrot on humans and on the other hand it influences the crystallization process.

The following investigations are planned:

Investigation of the influence of different varieties on the quality of carrots.
Investigation of the influence of different locations on the quality of the individual carrot varieties.
Investigation of the different intensities of juice processing on the quality.
Possible relationship between sensory evaluation of the carrot varieties and the described qualities of the crystallization images.
Investigation of carrot juice samples with different pectin contents in terms of the crystallization behavior and the resulting patterns (clarification of the relationship between processing and crystallization).
Investigation of the behavior of pectin depending on the structure and the mixing ratio on the crystallization behavior and the resulting patterns (clarification of the influence of the mixing ratio).
Investigation of the influence of different structures of pectin on the crystallization behavior and the resulting patterns (clarification of the relationship between sample and image).