Die chronologische Liste zeigt aktuelle Veröffentlichungen aus dem Forschungsbetrieb der Hochschule Weihenstephan-Triesdorf. Zuständig ist das Zentrum für Forschung und Wissenstransfer (ZFW).
The assessment of tomato fruit quality depends on a variety of extrinsic and intrinsic quality parameters such as color, firmness and sugar content. Conventional measurement methods of these quality parameters are time consuming, require various measurement devices, and in case of intrinsic quality, involve destructive measurements. Latest research focused on the non-destructive determination of these parameters by using spectroscopic measurements. The goal of this study was to evaluate the capability of three commercial-ly available portable and miniaturized VIS/NIR spectrometers, socalled food-scanners, in predicting various tomato quality attributes in a non-destructive way. Additionally, this study evaluated the software provided by manufacturers for building of prediction models by comparing the results derived from those software tools to state-of-the-art software for multivariate analysis. Evaluation of food-scanner spectra resulted in prediction models of high accuracy (r² > 0.90) for tomato fruit firmness, dry matter, total soluble solids and color values L*, a* and h°. Prediction models computed with manufacturer’s software showed similar accuracy to those derived from state-of-the-art evaluation software. Results of this study illustrate the great potential of commercial food-scanners for non-destructive quality measurement. Further important features of food-scanners with respect to the application along the fresh produce supply chain are addressed.
Das Indoor Vertical Farming spezialisiert sich auf die Produktion von Pflanzen in mehrlagigen, vertikal angeordneten Kultursystemen in einer geschlossenen Gebäudestruktur (Container, Lagerhallen, etc.). Die Lichtenergie für das Pflanzenwachstum wird über künstliche Belichtungssysteme wie LED-Module zur Verfügung gestellt. Von der Temperatur über die Luftfeuchte, Belichtungszeit und -intensität, dem Lichtspektrum bis hin zur Bewässerung kann alles gezielt eingestellt und optimiert werden. Sensoren und Kamerasysteme ermöglichen zudem das Wachstum und die pflanzliche Entwicklung in Echtzeit zu beobachten und kontinuierlich zu optimieren.
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Nirit Havardi-Burger,
Prof. Dr. Heike Susanne Mempel,
Prof. Dr. Vera Bitsch
The study investigated the value chain of flowering potted plants supplying the German market and the drivers influencing chain actors. The study builds on strategic and horticultural value chain literature. Data was collected by conducting 20 in-depth interviews with chain actors from different stages in the value chain and analyzed through qualitative content analysis. Results showed that the value chain of flowering potted plants is divided in two pathways due to distinct propagation methods, either generative (seeds) or vegetative (cuttings). Whereas propagation material is generally produced in southern countries, such as Africa and Central America, young plants and potted plants are cultivated within Europe. The paper identified driving forces such as retailer requirements, weather conditions, price pressure and innovations. Furthermore, the study provides an overview of chain activities and processes to help the sector anticipate developments, and support stakeholders in future decisions.
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M.Sc. Simon Goisser,
Sabine Wittmann,
Michael Fernandes,
Prof. Dr. Heike Susanne Mempel,
Christian Ulrichs
Lycopene, the red colored carotenoid in tomatoes, has various health benefits for humans due to its capability of scavenging free radicals. Traditionally, the quantification of lycopene requires an elaborate extraction process combined with HPLC analysis within the laboratory. Recent studies focused simpler methods for determining lycopene and utilized spectroscopic measurement methods. The aim of this study was to compare non-destructive methods for the prediction of lycopene by using color values from colorimeter measurements and Vis/NIR spectra recorded with three commercially available and portable Vis/NIR spectrometers, so called food-scanners. Tomatoes of five different ripening stages (green to red) as well as tomatoes stored up to 22 days after harvest were used for modeling. After measurement of color values and collection of Vis/NIR spectra the corresponding lycopene content was analyzed spectrophotometrically. Applying exponential regression models yielded very good prediction of lycopene for color values L*, a*, a*/b* and the tomato color index of 0.94, 0.90, 0.90 and 0.91, respectively. Color value b* was not a suitable predictor for lycopene content, whereas the (a*/b*)² value had the best linear fit of 0.87. In comparison to color measurements, the cross-validated prediction models developed for all three food-scanners had coefficients of determination (r²CV) ranging from 0.92 to 0.96. Food-scanners also can be used for additional measurements of internal fruit quality, and therefore have great potential for fruit quality assessment by measuring a multitude of important fruit traits in one single scan.
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M.Sc. Simon Goisser,
Prof. Dr. Heike Susanne Mempel,
Prof. Dr. Vera Bitsch
Originally advertised as tools for end-consumers, portable food-scanners have recently reached a high level of awareness and show potential as instruments for quality assessment along fruit and vegetable supply c hains. The current study explores preferences and concerns of chain actors regarding the implementation of this technology through semi-structured interviews. Results indicate that food-scanners could facilitate quality control at different levels of the fresh produce supply chain by providing fast, non-destructive and objective measurements. Concerns about the application of food-scanners could be identified with respect to potential additional requirements of fruit wholesaler resulting in more pressure on producers. To further a goal-oriented and user-directed development of this new technology, future research should be directed at its impacts on perception of fruit quality along the chain as well as end-consumers’ readiness to use these devices in everyday life.
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Nirit Havardi-Burger,
Prof. Dr. Heike Susanne Mempel,
Prof. Dr. Vera Bitsch
This study investigated the sustainability challenges and the adoption of sustainability innovations along the value chain of flowering potted plants supplying the German market. Data was collected through eighteen in-depths interviews with chain actors from different stages of the value chain and analyzed through qualitative content analysis. The material flow of the value chain begins at the breeding level followed by the propagation level. Cuttings are produced mostly in African countries, rooted cuttings and potted plants are cultivated in Europe. The main environmental challenges include water scarcity, pesticide use and carbon footprint. Social challenges in Africa include low wages and difficult working conditions. In Germany, social challenges include recruitment and retention of employees and product transparency. Economic challenges include profitability and the need to comply with standards. Sustainability driven innovations can address some sustainability challenges. However, their implementation often leads to increased costs, financial risk and complexity of implementation. Furthermore, the lack of product transparency prevents the transfer of sustainability costs to the consumer by offering a sustainable product for a premium price. Business-to-business standards have generally had a positive influence on the adoption of sustainability innovations. But by setting certification as an entry barrier for suppliers, retailers have become more powerful chain actors.
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Prof. Dr. Heike Susanne Mempel,
Sabine Wittmann
Berechtigungen: Peer Reviewed
Potential and use of artificial lighting in horticulture (2019) Light and Engineering 27 , S. 31-41.
The use of supplemental lighting in horticulture is continuously increasing. Compared to HPS luminaires LED have significant advantages like the possibility of a targeted compilation of the spectrum, the use of dimmable and dynamic adaptable luminaires, the insensitivity to the switching frequency, less heat radiation and the and the high energy efficiency. Experiments with monochromatic lighting show potentials for influencing various quality factors with specialized light spectra in order to reach the targeted plant quality. However, many questions are still open, resulting in a rather low transfer rate of specific lighting strategies in the applied horticulture. Beneficial effects of interlighting were shown in greenhouse experiments and their potentials discussed. In the future higher requirements on plant and fruit quality and a sustainable use of resources will result in a greater importance for specialized lighting strategies and advanced technological solutions.
Dr. rer. pol. Paul Lampert,
Prof. Dr. Vera Bitsch,
M.Sc. Daniel Berki-Kiss,
Prof. Dr. Swantje Duthweiler,
Dipl.-Biol. Daniel Hauck,
Nirit Havardi-Burger,
Prof. Dr. Elke Meinken,
Prof. Dr. Heike Susanne Mempel,
Prof. Dr. Luisa Menapace,
Prof. Dr. Klaus Menrad,
Stefan Pauleit,
Urs Schmidhalter,
M.Sc. Laura Stratopoulos
Der Bericht fasst die Ergebnisse von vier Teilprojekten zum Thema Nachhaltigkeit im Gartenbau zusammen. Das erste Teilprojekt untersucht den Düngewert sekundärer Phosphorstoffe für Gartenbaupflanzen. Das zweite Teilprojekt entwickelt Nachhaltigkeitskriterien für die Wertschöpfungskette blühender Topfpflanzen. Das dritte Teilprojekt untersuchte die Verwendbarkeit von Bäumen aus trockeneren Umgebungen in städtischen Umgebungen. Das vierte Teilprojekt beschäftigt sich mit Verbraucheraspekten in Bezug auf Fairtrade Schnittrosen in Deutschland.
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Gerhard Radlmayr
Referent für Wissenstransfer und Forschungskommunikation
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