From needles to pattern in food quality determination

Kinesthetic engagement in Gestalt evaluation outscores analytical 'atomic feature' evaluation in perceiving aging in crystallization images of agricultural products

There is an increasing interest in a systemic approach to food quality. From this perspective, the copper chloride crystallization method is an interesting asset as it enables an estimation of a sample's 'resilience' in response to controlled degradation. In previous studies, we showed that an ISO-standardized visual evaluation panel could correctly rank crystallization images of diverse agricultural products according to their degree of induced degradation. In this paper we examined the role of contextual sensitivity herein, with the aim to further improve the visual evaluation. To this end, we compared subjects' performance in ranking tests, while primed according to two perceptional strategies (levels: analytical vs. kinesthetic engagement), according to a within-subject design. The ranking test consisted out of wheat and rocket lettuce crystallization images, exhibiting four levels of induced degradation. The perceptual strategy imbuing kinesthetic engagement improved the performance of the ranking test in both samples tested. To the best of our knowledge, this is the first report on the training and application of such a perceptual strategy in visual evaluation.

Influence of dewetting on the crystallization behavior of CuCl₂ in the presence of BSA during evaporation in a Petri dish

The overall structure of dihydrate cupric chloride (CuCl₂ * 2H₂O) crystallization patterns in the presence of bovine serum albumin (BSA) in a Petri dish is influenced by dewetting. The dewetting behavior, which can be either before or after initial CuCl₂ nucleation, depends on the amount of CuCl₂ and BSA in the Petri dish. We postulate that the concentration and/or temperature gradient area in the dish, which is built up during the evaporation process, coincides with the location where dewetting predominantly starts. This hypothesis could be supported by measurements of the CuCl₂ coverage of the Petri dish. During the evaporation the height of the meniscus at the rim of the Petri dish recedes in favor of the central Petri dish area. This could not be explained by the above mentioned hypothesis.