Wine quality under integrated, organic and biodynamic management using image-forming methods and sensory analysis

Background and aims The image-forming methods copper chloride crystallization, capillary dynamolysis and circular chromatography are presented as an instrument for assessing wine quality. Wine quality of samples from a long-term field trial comparing integrated, organic and biodynamic management were investigated by using image-forming methods and sensory analysis. Methods and results Concerning the image-forming methods copper chloride crystallization, capillary dynamolysis and circular chromatography, the images of encoded samples were (i) grouped into pairs with similar image features; (ii) characterized based on reference images (e. g. high–low resistance to degradation); (iii) ranked (according to the characterization), and (iv) assigned to the different production methods (classified). Wine samples from organic and biodynamic management needed less wine per sample for a similar expression of structural characteristics than wine samples from integrated cultivation. Organic and biodynamic samples also show structures that indicate less degeneration than integrated samples. Due to these properties, nine coded wine samples from 2010 could be (i) grouped, (ii) characterized, (iii) ranked and (iv) classified without errors, i.e., assigned to the cultivation methods of integrated, organic and biodynamic agriculture. In sensory analysis, the wine derived from biodynamic management had the highest aroma intensity. In the other parameters the differences were not significant. Conclusion Analysis with the image-forming methods copper chloride crystallization, capillary dynamolysis and circular chromatography complements sensory analysis for a more complete description of the characteristic properties of wines originating from different management systems. Significance of the study If further studies confirm these results, the image-forming methods copper chloride crystallization, capillary dynamolysis and circular chromatography may be developed as a complementary tool to sensory and chemical analysis in assessing wine quality. Graphic abstract

Quality assessment of grape juice from integrated, organic and biodynamic viticulture using image forming methods

Aim: The image forming methods biocrystallisation, capillary dynamolysis and circular chromatography are introduced as a complementary tool for grape quality assessment. These methods were used to investigate grape juice samples from a long-term field trial comparing integrated, organic and biodynamic viticultural practices.Methods and results: Characteristic changes in structures created by the reaction of metal salts with grape juice were evaluated using biocrystallisation, circular chromatography and capillary dynamolysis image forming methods. In particular, this study tested the effects of cultivation method, aging time and juice concentration on structure formation.To assess grape quality, the images of the encoded grape juice samples were: i) grouped into pairs with similar image features, ii) characterised based on reference images (e.g., high versus low resistance to degradation, or the amount of substance necessary for structure formation), iii) ranked according to structures associated with grape quality, and iv) assigned to the different production methods (classification). In order for similar structural features in the image forming methods to be expressed, all samples of grape juice harvested from integrated production over four years required higher juice concentrations than samples from organic and biodynamic origin. This was interpreted as the latter two production systems having higher structure formation efficacy. Furthermore, juices produced from the integrated management system exhibited more structures, indicative of a lower resistance to aging. In three out of four harvest years, the biodynamic samples exhibited the highest structure forming efficacy and resistance to aging.Conclusion: These findings are consistent with enhanced form maintenance and thus higher internal product quality of biodynamic and organic grapes compared to grapes from integrated farming.Significance and impact of the study: Image forming methods may serve as a valuable tool for grape juice and wine quality assessment to complement compound-specific chemical analyses.

Paper Chromatography to Detect Predation on Mites

Predators that have fed on Panonychus ulmi (Koch) and Bryobia arborea Morgan and Anderson can be distinguished by the orange and reddish carotenoid biochromes derived from the prey. Predation on the two species of mites cannot be clearly separated. The predators are squashed on filter paper and the pigments separated by circular chromatography in a mixture of one part of zylene to four parts of white kerosene. The mite pigments are considerably altered during digestion in the predators. The method does not reveal the number of mites consumed by a predator, owing to differences in the pigment content of the various stages of the prey and in the time the pigments are retained in the predators.

CIRCULAR PAPER CHROMATOGRAPHIC METHOD FOR DETERMINING TRACE AMOUNTS OF COBALT, COPPER, NICKEL, AND ZINC IN ROCKS AND SOILS

Ascending, descending, and horizontal (circular) methods of paper chromatography were explored and compared. Circular chromatography was found to be the most suitable; it requires shorter development time, has more definite Rf values, less tailing, higher sensitivity, and better precision than ascending or descending methods.A methyl ethyl ketone: hydrochloric acid solution (93:7 v/v) is used as a developing solvent for cobalt, copper, and nickel, and a 1-butanol: 1 N hydro–chloric acid solution (7:3 v/v) is used as a solvent for zinc. Good separations were obtained with these solvents and no critical interferences were noted. Benzidine – rubeanic acid is used as a color indicator for cobalt, copper, and nickel; and dithizone (0.01%) for zinc. This method has an absolute sensitivity of 0.005 μg for zinc, and 0.02 μg for cobalt, copper, and nickel. Precision is estimated at ± 10%.Methods have also been developed for determining bismuth, silver, and tin.The separation of elements from complex mixtures by paper chromatography and by quantitative determination of the amounts present by emission spectrography have been investigated. This rarely considered process offers promise, because the sensitivity of several elements is higher in emission spectrography than in colorimetry.