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Electrohydrodynamic drying versus conventional drying methods: A comparison of key performance indicators
2023, Iranshahi, Kamran, Rubinetti, Donato, Onwude, Daniel I., Psarianos, Marios, Schlüter, Oliver K., Defraeye, Thijs
Preserving fruits and vegetables by drying is a traditional yet effective way of reducing food waste. Existing drying methods are either energy-intensive or lead to a significant reduction in product quality. Electrohydrodynamic (EHD) drying is an energy-efficient low-temperature drying method that presents an opportunity to comply with the current challenges of existing drying methods. However, despite its promising characteristics, EHD drying is yet to be accepted by industry and farmers. The adoption of EHD drying is hindered due to different reasons, such as uncertainties surrounding its scalability, quality of dried product, cost of operation, and sustainability compared to conventional drying methods. To address these concerns, this study quantifies and benchmarks the Key Performance Indicators (KPIs) of EHD drying compared to the standard conventional drying methods based on lab-scale experiments. These drying methods include hot-air, freeze, microwave, and solar drying. The results show that drying food using EHD is at least 1.6, 20, and 70 times more energy-efficient than the microwave, freeze, and hot-air, respectively. Similar results could be observed for exergy efficiency. EHD drying has superior product quality compared to other drying methods. For instance, it could retain 62% higher total phenolic content with 21% less color degradation than freeze-drying. Although microwave drying resulted in significantly higher drying kinetics than other techniques, EHD performed better than solar and freeze-drying but was comparable with hot-air drying. EHD drying also shows promising results in economic performance assessment. It is the cheapest drying method after solar drying and has the highest estimated net present value (NPV) after hot-air drying. Overall, compared to the currently used drying methods for small to medium-scale drying, EHD was found to be a more exergy and energy-efficient, cost-effective, and sustainable alternative that can provide higher-quality dried products. However, its drying kinetics should be improved for industrial applications.
Composite materials for innovative urban farming of alternative food sources (macroalgae and crickets)
2022, Fricke, Anna, Psarianos, Marios, Sabban, Jakob, Fitzner, Maria, Reipsch, Riccardo, Schlüter, Oliver K., Dreyer, Christian, Vogt, Julia H.-M., Schreiner, Monika, Baldermann, Susanne
Facing an inexorable growth of the human population along with substantial environmental changes, the assurance of food security is a major challenge of the present century. To ensure responsible food consumption and production (SDG 12), new approaches in the food system are required. Thus, environmentally controlled, sustainable production of alternative food sources are of key interest for both urban agriculture and food research. To face the current challenge of integrating food production systems within existing structures, multidisciplinary discourses are required. Here, we bring together novel technologies and indoor farming techniques with the aim of supporting the development of sustainable food production systems. For this purpose, we investigated the feasibility of 10 composite materials for their innovative use as structural support in macroalgal cultivation (settlement substrates) and cricket rearing (housing). Considering material resistance, rigidity, and direct material-organism interactions, the bio-based composite polylactic acid (PLA) was identified as a suitable material for joint farming. For macroalgae cultivation, PLA sustained the corrosive cultivation conditions and provided a suitable substrate without affecting the macroalgal physiology or nutritional composition (carotenoids and chlorophylls). For cricket rearing, PLA provided a suitable and recyclable shelter, which was quickly accepted by the animals without any observed harm. In contrast, other common composite components like phenolic resin or aramid were found to be unsuitable due to being harmful for the cultivated organisms or instable toward the applied sterilization procedure. This multidisciplinary study not only provides profound insights in the developing field of urban indoor food production from a new perspective, but also bridges material science and farming approaches to develop new sustainable and resilient food production systems.
Effect of Narrowband UV-B Irradiation on the Growth Performance of House Crickets
2022, Psarianos, Marios, Fricke, Anna, Ojha, Shikha, Baldermann, Susanne, Schreiner, Monika, Schlüter, Oliver K.
Indoor co-cultivation systems can answer to the need for sustainable and resilient food production systems. Rearing organisms under light-emitting diodes (LEDs) irradiation provides the possibility to control and shape the emitted light spectra. UV-B-irradiation (280–315 nm) can positively affect the nutritional composition of different plants and other organisms, whereas information on edible insects is scarce. To evaluate the potential effect of the photosynthetically active radiation (PAR) and LED-emitting LEDs on the rearing and nutritional quality of edible insects, house crickets (Acheta domesticus) were reared from the age of 21 days under controlled LED spectra, with an additional UV-B (0.08 W/m2) dose of 1.15 KJm2 d−1 (illuminated over a period for 4 h per day) for 34 days. UV-B exposure showed no harm to the weight of the crickets and significantly increased their survival by ca. 10% under narrowband UV-B treatment. The nutritional composition including proteins, fat and chitin contents of the insects was not affected by the UV-B light and reached values of 60.03 ± 10.41, 22.38 ± 2.12 and 9.33 ± 1.21%, respectively, under the LED irradiation. Therefore, house crickets can grow under LED irradiation with a positive effect of narrowband UV-B application on their survival.