Open Access

Abstract Broccoli (Brassica oleracea var. italica) is a highly perishable crop. The aim of the work presented here is to find ways to predict storability of broccoli shortly after harvest. Several methods are examined regarding their suitability for predicting broccoli storability. The non-destructive, optical measuring devices used in this work represent some of the common methods used for scientific quality assessment (color determination, chlorophyll fluorescence analysis). In addition, spectral data from diffuse reflection measurements, from both spot measurements and hyperspectral images, was evaluated. The generative development of broccoli curds was studied using diameters both of single buds and of whole curds, and was related to subsequent storability. The concentrations of the chlorophylls a and b, green chlorophyll catabolites chlorophyllide a (Chlide), pheophytin a (Pheoin), pheophorbide a (Pheoide) and carotenoids ß-carotene (ß-Car), lutein (Lut), neoxanthin (Nx) and violaxanthin (Vx) were determined in floral buds of broccoli through the use of high pressure liquid chromatography (HPLC). The goal was to determine if chlorophyll catabolites may function as indicators of broccoli storability and, furthermore, to relate the concentrations of photosynthetic pigments to the color change of broccoli during storage. In order to investigate effects from the field on the subsequent storability of broccoli, cultivation methods were altered. Plants were partly covered with covers of different materials, which affected the quantity and quality of incident global radiation. The application of fertilizers was specifically varied in one broccoli batch. Additionally, the influence of climatic events on the shelf life of broccoli was analyzed by querying an established database. The non-destructive indexes that proved to be most sensitive to changes during storage were the levels of photosynthetic efficiency (Fv/Fm, ΦPSII), the CIELAB color space coordinate on a blue to yellow scale (b*) and the inflection point of reflection spectra in the transition region from dark red to infrared electromagnetic wavelength range (REIP). However, based on parameter sensitivity, the prediction of value levels after four days of storage at 16 °C and high relative humidity (RH) (~ 95 %) was unfeasible. Quality indexes that changed on the same storage day did not necessarily end up at the same value level. Additionally, values of both Fv/Fm and ΦPSII did not adequately reflect the quality status of broccoli when different harvest batches were compared. In hyperspectral images, early quality changes were effectively rated based on Euclidean distances within broccoli curds and were displayed using reflection intensities at three wavelengths within the visible electromagnetic spectrum as RGB channels. The observed variation within broccoli curds was related to differences in the degree of senescence of single floral buds. However, the diameters of floral buds did not correspond to a rating of storability. In contrast, curd diameters within individual harvest batches were related to subsequent yellowing. The yellowing of broccoli was based on the decomposition of chlorophyll, which unmasked the carotenoids present. No accumulation of chlorophyll catabolites was found during storage. A trend towards rapidly increasing chlorophyll a/b ratios was observed in a broccoli batch with particularly high storability. Different N-fertilization of broccoli curds closely corresponded both with values of initial lightness L* of the CIELAB color space (R² = 0.70) and normalized difference vegetation index NDVI (R² = 0.73). Yet, N-fertilization had no impact on further storability. A negative impact on storability was observed when the spectrum of incident radiation on the field was temporarily reduced by using plastic covers with limited transmittance (λ = 400-500 nm). In a similar way, an increased number of hours with high solar radiation intensity (> 600 W m-2) during cultivation had a negative impact on broccoli storability (R² = 0.47). The impact of high irradiation partly corresponded with temperatures higher than 25 °C (R² = 0.29). A strong predetermination of curd storability was observed based on the water availability for broccoli plants in the last two weeks before harvest (R² = 0.71). A successful prediction of broccoli storability is therefore most likely to be conducted by looking at effects during cultivation. For early non-destructive evaluation of the current quality status of broccoli, both the parameter b* and the spectral index REIP were highly suitable. Therefore, through the help of monitoring systems throughout cultivation (database of climate and cultivation incidents) in combination with reflection-based, hand-held devices during storage, the prediction and rating of broccoli storability can certainly be improved.

The application of cold atmospheric pressure plasma (CAPP) was suggested as an innovative nonthermal technology for inactivating undesirable microorganisms on the surface of heat-sensitive food products. Moreover, CAPP may offer a promising approach for the tailored modification of product properties along value-added chains of plant and animal related products. Therefore, this thesis puts emphasis on providing evidence for the possible utilization of plasma-induced surface and ingredient interactions as a tool for the selective modification of secondary metabolite profiles in plants and techno-functionality of flours and proteins from peas. Further, the knowledge gained on plasma assisted modification of plant-based materials was transferred to animal-based materials from edible insects taking additionally into account microbial decontamination as another key issue in insect processing. The thesis imparts the detailed characterization of selected raw materials, the identification of proper CAPP setups and corresponding product-specific process parameters by performing process accompanying monitoring of plasma characteristics required to achieve desired modifications. Detailed investigations of the plasma-induced effects were conducted following a top-down approach by using suitable analytical methods providing insights into possible underlying mechanisms from macroscopic to molecular level. The macroscopic level of analysis included quality (color/texture), compositional (protein/fat/dry matter contents) and microbial (surface/overall total viable counts) methods, followed by determining techno-functional (water/fat binding/emulsification) and protein (solubility/water/fat binding/emulsification) properties, as well as protein structure (surface hydrophobicity/fluorescence properties/CD spectroscopy) on the microscopic and structural level, down to analysis of the protein composition (SDS-PAGE/tryptophan content/amino acid composition) on the molecular level. The results provide a scientific basis regarding the targeted use of the CAPP technology for functionalization and modification of high-protein food components and could therefore contribute to the bio-economic and resource efficient production of dry high-value protein products, as protein functionality plays a key role in improving existing products, developing new products, and utilizing alternative protein sources as new ingredients. Consequently, feedback on the applicability of CAPP for tested raw materials was derived by evaluating the effectiveness of the treatment regarding the desired process goal, and by identifying product-specific characteristics allowing transferability of the CAPP process with the long-term goal of combining plasma treatments with existing unit operations in established product-specific process lines. Initial approaches regarding the CAPP treatment of complex food matrices by using a plasma device, which is promising for the application in industrial scale, aimed at the development of innovative process combinations with focus on “plasma-drying” as a prospective future unit operation, which may contribute to reducing the expected costs of CAPP treatments. The potential of CAPP processing to become a routine tool for the food industry in the coming years is also reflected throughout all parts of this work, and thus, it provides a substantial contribution to promoting the successful admission of the CAPP technology in the food sector.

Ziel des Leitfadens ist die Vermittlung von grundlegenden Informationen über die Trocknung von Arznei- und Gewürzpflanzen. Maximale Energieeffizienz ist entscheidend für die wirtschaftliche Effizienz von Trocknungsanlagen. Eine maximale Auslastung im Verlauf der Ernteperiode besitzt absolute Priorität. Die Betriebsweise von Trocknern und wechselnde Wetterbedingungen haben einen wesentlich größeren Einfluss auf den spezifischen thermischen Energiebedarf als das Trocknungsverhalten einzelner Pflanzenarten. Zuerst sollten deshalb die jeweiligen Trocknungsprozesse luftseitig und regelungstechnisch optimiert werden. Die Realisierung einer effizienten Energieversorgung ist dann der zweite Schritt. Zu den Möglichkeiten der lufttechnischen Effizienzsteigerung zählt insbesondere die Trocknung mit Teilumluft. Wird der Umluftanteil optimal geregelt, so verlängert sich die gesamte Trocknungsdauer nur geringfügig. Andere effektive Maßnahmen bei der Chargentrocknung sind die Nutzung von Abluft in nachgeschalteten Trocknern oder die Umlagerung und Zusammenlegung von angetrockneten Arzneipflanzen auf einer kleineren Rostfläche. Alle diese Maßnahmen ermöglichen Energieeinsparungen von mehr als 25 %. Basierend auf Simulationsergebnissen zur Flächentrocknung von Kamilleblüten wurden verschiedene Varianten der Energieversorgung vergleichend analysiert. Bei ununterbrochener Trocknung über mehrere Tage und Nächte sind die durch Solarwärme erreichbaren Energieeinsparungen relativ klein. Die Kombination einer Wärmepumpe mit einem Blockheizkraftwerk (BHKW) und Teilumluft ergab hingegen Primärenergieeinsparungen von 73 %. Wirtschaftlichkeitsanalysen zeigen, dass sich der geregelte Teilumluft-Betrieb in weniger als zwei Jahren amortisiert. Unter Berücksichtigung von Fördermitteln wurden für die untersuchten Varianten Nutzung von BHKW-Abwärme, Kombination Wärmepumpe und BHKW sowie Nutzung von Solarwärme Amortisationsdauern zwischen ca. sechs und zehn Jahren ermittelt.

In der Ausgabe 93 der Schriftenreihe „Bornimer Agrartechnische Berichte“ (BAB) werden referierte Langfassungen von Beiträgen des 22. und 23. Computer-Bildanalyse-Workshops (CBA) zusammengefasst und veröffentlicht. Ziel der jährlichen Workshop-Reihe ist unter anderem die Vertiefung des Erfahrungsaustauschs zwischen Forschergruppen in der Anwendung von bildgebenden und spektroskopischen Methoden in der Landwirtschaft und im Gartenbau. Wie in den Vorjahren decken die Workshops 2016 und 2017 eine große Bandbreite von Themen ab wie die berührungslose Sensorik, die automatisierte Bildanalyse, Hyperspektralanalysen, sowie neue Ansätze autonomen Phytomonitorings durch Boden- und Flugroboter auf Ackerflächen oder in Obstplantagen. Mit neuen Ansätzen der räumlichen Datenanalyse können hierbei einzelne Produktionsschritte teilflächenspezifisch optimiert werden, eine Herangehensweise, die als Precision Agriculture und in Verbindung mit mobilen, intelligenten Kommunikationsmitteln als "Smart Farming" bezeichnet wird. Globale Vision ist es, die digitalisierten Produktionssysteme so eng zu vernetzen dass die landwirtschaftliche Produktion adaptiv beeinflusst werden kann und somit ressourceneffizient und nachhaltig wird. Für viele landwirtschaftliche Anwendungsfälle sind noch keine passenden Lösungen verfügbar, so dass für die spezifischen Einsatzbedingungen eigenständige Lösungen erarbeitet werden müssen. Hier setzt die zielgerichtete Grundlagenforschung an, die in der nächsten Dekade begünstigt durch die steigende Verfügbarkeit günstiger elektronischer Bauteile, spezielle Anwendungen für die Landwirtschaft hervorbringen wird. Dabei neu entstehende Strukturen könnten die gewohnten Abläufe in der Landwirtschaft in Zukunft fundamental ändern. In 2016 fand der CBA-Workshop zum ersten Male an der Hochschule Harz in Wernigerode statt. In 2017 kehrte die Workshopreihe zurück an ihren Ursprung nach Potsdam, an das Leibniz-Institut für Agrartechnik und Bioökonomie e.V. Wir danken den Referenten und allen an der Organisation beteiligten Personen für zwei erfolgreiche Workshops.

The present Symposium on Sensing Plant Water Status will provide a Plattform to Exchange findings on established and new methods - considering the fundamentals of the mothology as well as helful hints achieved in applications. Various ISHS groups will be involved such as the Commission Irrigation and Plant Water Relations, the Workgroup Water Supply and Irrigation and the Work Group Water Relations. Main issue will be classical and recent techniques of sensing plant water Status, from the cell to the orchard, and their applications in horticultural science. hence this Symposium will bring together reseachers from the diverse fields of plant water Relations study.