Publications by authors named "Johannes Kahl"

The overall structure of dihydrate cupric chloride (CuCl * 2HO) 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 CuCl 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.

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This review summarises existing evidence on the impact of organic food on human health. It compares organic vs. conventional food production with respect to parameters important to human health and discusses the potential impact of organic management practices with an emphasis on EU conditions.

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Organic production and consumption provide a delineated food system that can be explored for its potential contribution to sustainable diets. While organic agriculture improves the sustainability performance on the production side, critical reflections are made on how organic consumption patterns, understood as the practice of people consuming significant amounts of organic produce, may also be taken as an example for sustainable food consumption. The consumption patterns of regular organic consumers seem to be close to the sustainable diet concept of FAO.

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The market for processed food is rapidly growing. The industry needs methods for "processing with care" leading to high quality products in order to meet consumers' expectations. Processing influences the quality of the finished product through various factors.

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Background: There is a need for authentication tools in order to verify the existing certification system. Recently, markers for analytical authentication of organic products were evaluated. Herein, crystallization with additives was described as an interesting fingerprint approach which needs further evidence, based on a standardized method and well-documented sample origin.

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Although several meta-analysis studies have been published comparing the quality of food derived from organic and non-organic origin, it is still not clear if food from organic production per se can guarantee product-related added value to consumers. This paper aims to summarize the status quo in order to identify research gaps and suggest future research challenges. Organic food is described according to a quality model already published.

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In 2007 EU Regulation (EC) 834/2007 introduced principles and criteria for organic food processing. These regulations have been analysed and discussed in several scientific publications and research project reports. Recently, organic food quality was described by principles, aspects and criteria.

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Organic food quality determination needs multi-dimensional evaluation tools. The main focus is on the authentication as an analytical verification of the certification process. New fingerprinting approaches such as ultra-performance liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, direct analysis in real time-high-resolution mass spectrometry as well as crystallization with and without the presence of additives seem to be promising methods in terms of time of analysis and detecting organic system-related parameters.

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The aim of this review is to provide an update on factors contributing to quality of carrots, with special focus on the role of pre- and postharvest factors and processing. The genetic factor shows the highest impact on quality variables in carrots, causing a 7-11-fold difference between varieties in content of terpenes, β-carotene, magnesium, iron and phenolics as well as a 1-4-fold difference in falcarindiol, bitter taste and sweet taste. Climate-related factors may cause a difference of up to 20-fold for terpenes, 82% for total sugars and 30-40% for β-carotene, sweet taste and bitter taste.

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Background: There is a need to advance the study of the effects of organic and conventional systems on product quality. In particular, little is known about the importance of different farming practices concerning nutrient cycling and the use of external inputs within organic farming for the quality characteristics of the products. In this study the quality characteristics of carrot grown under different farming practices (conventional and three organic cropping systems) over a two-year period were analysed with the aim of discriminating between organic and conventional and investigating the effect of different organic farming practices concerning nutrient recycling and use of external nutrient input.

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As a contribution to the debate on the comparison of nutritional quality between conventional versus organic products, the present study would like to provide new results on this issue specifically on dairy products by integrating the last 3 years' studies using a meta-analysis approach with Hedges' d effect size method. The current meta-analysis shows that organic dairy products contain significantly higher protein, ALA, total omega-3 fatty acid, cis-9,trans-11 conjugated linoleic acid, trans-11 vaccenic acid, eicosapentanoic acid, and docosapentanoic acid than those of conventional types, with cumulative effect size ( ± 95% confidence interval) of 0.56 ± 0.

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Consumers buy organic food because they believe in the high quality of the product. Furthermore, the EU legal regulatory framework for organic food and farming defines high quality of the products as an important goal of production. A major challenge is the need to define food quality concepts and methods for determination.

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The overall structure of the crystallization results of dihydrate cupric chloride with additives in a petri dish is affected by the duration between the beginning of the evaporation and the start of the crystallization. Experiments done with polyvinylpyrrolidone and freeze-dried carrot as additive are compared with those of the additive free case. The dependency of dewetting on the dihydrate cupric chloride amount is discussed in terms of depletion of the solution and the surface tension properties of the system.

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The organic market is growing rapidly. This is because customers expect organic food to be authentic and healthy. For plant products the awareness of pesticide residues is one main point in customers' decisions for organic food, but in terms of secondary plant compounds, antioxidants are also expected benefits of organically produced foods.

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