Refine
Year of publication
- 2022 (70) (remove)
Document Type
- Conference Proceeding (32)
- Article (27)
- Other (3)
- Book (2)
- Report (2)
- Working Paper (2)
- Part of a Book (1)
- Moving Images (1)
Has Fulltext
- no (70) (remove)
Is part of the Bibliography
- yes (70) (remove)
Keywords
- Ernährungssysteme (2)
- 3,4-Dimethylpyrazole phosphate (1)
- 5:2 fasting (1)
- Agrarmarketing (1)
- Agri-environment scheme (1)
- Alternative peeling methods (1)
- Amino acid (1)
- Arable field (1)
- Baumpflege (1)
- Biodiversity conservation (1)
Institute
- Fakultät AuL (70) (remove)
Currently, only non-imaging chlorophyll fluorescence measurements are used to identify the Lower Oxygen Limit (LOL) in Dynamic Controlled Atmosphere - Chlorophyll Fluorescence (DCA-CF) storage. The disadvantage of non-imaging fluorescence is that no statement can be made about the spatial heterogeneity of the sample. In contrast, chlorophyll fluorescence imaging can detect spatial heterogeneity of photosynthetic activity and has been established in research for some decades because the information benefit is higher. In this study, the chlorophyll fluorescence (Fo, Fm, Fv, Fv/Fm) of apples (Malus x domestica, BORKH.) was measured with a fluorescence imaging system in situ during storage. Intact apples of ‘Braeburn’ and ‘Golden Delicious’ were stored under low-oxygen stress conditions (< 1 kPa). The metabolic shift from aerobic to fermentative metabolism was made visible with the chlorophyll fluorescence imaging and was spatially localized on the sample. Furthermore, a method was developed to identify the LOL based on the chlorophyll fluorescence imaging combined with the histogram division method. This method considers the heterogeneity of the fluorescence and bundles the measured Fo data as histograms. Our results showed that the fluorescence imaging combined with the histogram division method can be a powerful tool for identifying the LOL.
Background: New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to 86% of patients after transcatheter edge-to-edge repair of the mitral valve (TEER-MV). Knowledge of the exact procedural step(s) that carry the highest risk for cerebral embolisation may help to further improve the procedure.
Aims: The aim of this study was to identify the procedural step(s) that are associated with an increased risk of cerebral embolisation during TEER-MV with the MitraClip system. Furthermore, the risk of overt stroke and silent brain ischaemia after TEER-MV was assessed.
Methods: In this prospective, pre-specified observational study, all patients underwent continuous transcranial Doppler examination during TEER-MV to detect microembolic signals (MES). MES were assigned to specific procedural steps: (1) transseptal puncture and placement of the guide, (2) advancing and adjustment of the clip in the left atrium, (3) device interaction with the MV, and (4) removal of the clip delivery system and the guide. Neurological examination using the National Institutes of Health Stroke Scale (NIHSS) and cerebral MRI were performed before and after TEER-MV.
Results: Fifty-four patients were included. The number of MES differed significantly between the procedural steps with the highest numbers observed during device interaction with the MV. Mild neurological deterioration (NIHSS ≤3) occurred in 9/54 patients. New ischaemic lesions were detected in 21/24 patients who underwent MRI. Larger infarct volume was significantly associated with neurological deterioration.
Conclusions: Cerebral embolisation is immanent to TEER-MV and predominantly occurs during device interaction with the MV. Improvements to the procedure may focus on this procedural step.
Currently, the modelling of drying processes of plant tissues pre-treated by pulsed electric field (PEF) is following experimentally identified curves or separate heat and mass transfer and diffusion models with different levels of accuracy. This research had two major objectives: mathematical modeling and control of drying process of different vegetables pretreated by PEF during convective drying. The mathematical modeling was based on Luikov's heat and mass transfer model along with properties of different vegetables. Computer modelling was done using the difference method for predicting moisture and the temperature potentials of untreated and PEF-treated vegetables. The formulation and the solution procedures were applied to simulate the simultaneous heat and mass transfer in selected vegetables subjected to the convective drying. Suggested model had a good correlation with experimental results. Moreover, cell disintegration index can be used as a controllable parameter in heat and mass transfer models to predict drying behavior of potato, onion, and carrot tissues. Obtained drying models can be used as a mathematical tool to predict drying behavior for various types of agricultural products pre-treated by pulsed electric field.
The impact of Pulsed Electric Fields (PEF) on the peeling ability of different fruits and vegetables in particular tomatoes, peaches, peppers, and oranges were investigated. Samples were exposed to a fixed electric field strength of 2.15 kV/cm. The specific energy ranged from 0.6 kJ/kg to 50.3 kJ/kg. The treated raw materials were analysed regarding to the peeling ability, skin size and weight and firmness. The best result for tomatoes at a specific energy of 1.2 kJ/kg induced a high score of peeling ability that led to less product loss and could therefore increase the yield by 33.84%–41.53% compared to untreated samples. Moreover, an increased skin size by a factor of 3.7 was observed. However, PEF had no significant impact on peeling ability of oranges, peppers, and peaches. Although oranges showed an improvement in peeling ability by up to 32%, this cannot be traced back to the PEF treatment. The different properties and structures of the raw materials were discussed and provided indications about the limitation of PEF.
The present study investigates properties of heat-induced, self-standing gels of globular proteins. Native egg white protein (EWP) with 9,8 wt% protein and 0,395 wt% NaCl content was adjusted to pH = 7,0 and heated from 25 to 85 °C via Ohmic heating (OH) and conventional heating (COV) with respective come-up times (CUT, 240 and 1200 s) and holding times (HOLD, 30 and 900 s). Gels heated under OH showed lower denaturation levels and less water holding capacity. When HOLD was short, the firmness of OH gels exceeded COV gel firmness but deceeded at long HOLD. Similarly, at short HOLD OH samples presented higher hydrophobic interactions whereas at long HOLD COV gels showed more hydrophobic interactions. This correlated with changes of intermolecular beta-sheet structures which increased with HOLD at COV but decreased or remained unchanged during OH. Furthermore, as an SDS-PAGE revealed the main EWP, ovalbumin, did not fully denature when heated via OH, this lead to the assumption that the oscillatory electric field partially interferes the complete denaturation and development of intermolecular beta-sheet structures and hydrophobic interactions during thermal gelation of this protein. Scanning electron microscopy also showed deviances in network structures between OH and COV as COV gels exhibited a denser and OH gels a more open and porous network structure.
The impact of pulsed light (PL) treatment on naturally occurring microorganisms, mycotoxins, and on physicochemical properties in red pepper powder was investigated. Powder samples were exposed to different PL treatments up to 61 pulses, with fluence ranging from 1.0 to 9.1 J/cm2. The highest fluence applied (9.1 J/cm2, 61 pulses, 20 s) resulted in 2.7, 3.1, and 4.1 log CFU/g reduction of yeasts, molds, and total plate counts (TPC), where initial microbial loads were 4.6, 5.5, and 6.5 log CFU/g, respectively. At the same fluence intensity, a maximum reduction of 67.2, 50.9, and 36.9% of aflatoxin B1 (AFB1), total aflatoxins (AF), and ochratoxin A (OTA) were detected, respectively. Proportional increase in temperature of the samples was observed from the absorbed PL energy, reaching maximum of 59.8°C. The inactivation of investigated microorganisms and mycotoxins followed first-order kinetics (R2 > 0.95). The fluence intensity at 6.9 and 9.1 J/cm2 did not cause degradation, but rather a significant (p < .05) and apparent increase of total phenols. Total color difference (ΔE*) revealed only “slight differences,” compared to the untreated sample. In conclusion, higher reduction of microbial load and mycotoxins in red pepper powder could be achieved, when higher treatment intensity was applied. This suggests the PL as a potential technology for decontamination of red pepper powder and other spice powders.