Newest publications
Effect of liquefaction temperature and enzymatic treatment on bioethanol production from mixed waste baked products
(2025) Almuhammad, Mervat; Kölling, Ralf; Einfalt, Daniel; Almuhammad, Mervat; Yeast Genetics and Fermentation Technology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstraße 23, 70599, Stuttgart, Germany; Kölling, Ralf; Yeast Genetics and Fermentation Technology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstraße 23, 70599, Stuttgart, Germany; Einfalt, Daniel; Botanical Garden, Ulm University, Hans-Krebs-Weg, 89081, Ulm, Germany
This study investigates the effect of different liquefaction temperatures (50–70 °C) and four commercial enzyme formulations on glucose release and subsequent ethanol yield, using mixed waste baked products as a substrate. Among the enzymes tested, Amylase GA 500 proved to be superior in the hydrolysis of starch at lower temperatures (50 °C and 55°C). At higher liquefaction temperatures (65 °C and 70°C) all four enzyme preparations showed comparable activity. The highest glucose concentration (205.7 g/L) and the highest ethanol yield (92 g/L) were achieved with Amylase GA 500 at 65 °C. Its superior performance is attributed to the synergistic activity of α-amylase and glucoamylase, which facilitates efficient starch hydrolysis. Crucially, we discovered that the liquefaction temperature profoundly affects fermentation speed independently of the initial glucose concentration or the enzyme preparation used for starch hydrolysis. This novel mechanistic insight suggests that higher temperature treatment either makes an additional factor crucial for yeast fermentation available or depletes/destroys an inhibitor present in the complex waste bakery product matrix. These findings highlight the critical role of temperature and enzyme formulation in optimizing bioethanol production from bakery waste, supporting the development of more sustainable and efficient waste-to-biofuel processes.
Towards sustainable biointelligent food design: structuring potential of plant-based materials exemplified using apricot seed oil oleogels and bigels through 3D food printing
(2025) Reinmuth, Evelyn; Fahmy, Ahmed Raouf; Ribette, Olivia; Jekle, Mario; Reinmuth, Evelyn; Bioeconomy Office Hohenheim, University of Hohenheim, Stuttgart, Germany; Fahmy, Ahmed Raouf; Department of Plant-Based Foods, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany; Ribette, Olivia; Department of Plant-Based Foods, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany; Jekle, Mario; Department of Plant-Based Foods, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany
Background/Introduction: Biointelligence in the approach of food additive manufacturing represents a significant advancement, enabling the reverse engineering and design of foods. Legislation restricting trans-fats has accelerated research into alternatives, but ingredients like saturated and trans fats play key roles in food quality and functionality. Oleogels are a promising replacement. Food additive manufacturing introduces a biointelligent approach, combining biological and technical components with information technology to optimize food design. This study investigates 3D printing of oleogel and bigel systems using apricot seed oil, aiming to assess their significance, applicability, and printability as sustainable alternatives to trans fats for innovative, resource-efficient food production. Methods: Apricot seed oil, rich in antioxidants and polyunsaturated fatty acids, was processed into plant-based oleogels and bigels. The material systems were incorporated into 3D printed food structures. Material characterization and techno-functional analysis were conducted to evaluate the suitability of apricot seed oil for structuring 3D printed foods and controlling food texture. Results: Adjusting the type and concentration of oil-gelator mixtures enabled tailored texture and lipid distribution to fit consumer preferences. Sustainability impacts were assessed at intermediate processing steps, demonstrating the value of holistic evaluations beyond technical factors. Discussion: Biointelligent 3D printing offers a platform to optimize sensory and sustainability qualities in food design. The integration of apricot seed oil into novel food matrices enables versatile nutritional product development, supporting researchers and industry stakeholders in advancing consumer-centric, sustainable production and consumption practices.
Monomorium dine sp. nov. (Hymenoptera, Formicidae): a new inquiline social parasite ant species from North America
(2025) Cover, Stefan P.; Rabeling, Christian
Among the very rarest of Nearctic ants are three species of inquiline social parasites belonging to the genus Monomorium, namely Monomorium inquilinum DuBois, Monomorium pergandei (Emery), and Monomorium talbotae DuBois. All three species are known only from the type collections. Here, we describe Monomorium dine Cover & Rabeling, sp. nov., from the Navajo Nation in New Mexico, USA, a new species closely similar to the three known social parasites. Like them, M. dine appears to be a workerless inquiline that exploits a free-living Monomorium host. We also provide keys to the queens of the Nearctic Monomorium inquilines, provide the first images of these species, report new collections for Monomorium talbotae DuBois, discuss host-parasite associations, and summarize what is presently known about these mysterious social parasites.
Spatiotemporal climatic signals in cereal yield variability and trends in Ethiopia
(2025) Abera, Kidist; Gayler, Sebastian; Piepho, Hans‑Peter; Streck, Thilo; Abera, Kidist; Institute of Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Stuttgart, Germany; Gayler, Sebastian; Institute of Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Stuttgart, Germany; Piepho, Hans‑Peter; Biostatistics Unit, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany; Streck, Thilo; Institute of Soil Science and Land Evaluation, Biogeophysics, University of Hohenheim, Stuttgart, Germany
Climatic variability and recurrent drought can strongly affect the variability of crop yield and are therefore frequently considered a risk to food security in Ethiopia. A better understanding of how crop yields vary in space and time, and their relationship to climatic and other driving factors, can assist in enhancing agricultural production and adapting to and mitigating the impacts of climate change. We applied a multiple linear regression model to examine the spatiotemporal climatic signal (air temperature, precipitation, and solar radiation) in the yields of the most important crops (maize, sorghum, tef, and wheat) over the period 1995–2018. An analysis of the climatic data indicated that growing season temperature increased significantly in most regions, but the trends in precipitation were not significant. The yields of maize, sorghum, tef, and wheat tended to increase across most crop-growing areas, particularly in the west, but was highly variable. The results highlight large spatial differences in the contribution of climatic trends to crop-yield variability across Ethiopian regions. The trends in climatic variability did not significantly affect crop yields in some areas, whereas in the main crop-growing areas, up to − 39.2% of yield variability could be attributed to the climatic trends. Specifically, the climatic trends negatively affected maize yields but positively affected sorghum, tef, and wheat yields. Nationally, the average impacts of climatic trends on crop yields was relatively small, ranging from a 3.2% decrease for maize to a 0.7% increase for wheat. In contrast, technological advancements contributed substantially more to yield gains, with annual increases ranging from 4.3% for wheat to 5.1% for sorghum. These findings highlight the dominant role of non-climatic drivers, particularly improved agricultural technology, in shaping crop yield trends. Our findings underscore the spatial heterogeneity of climate impacts on agriculture and highlight the critical importance of technological progress in enhancing crop productivity. They also provide actionable insights for designing crop- and location-specific adaptation strategies, and stress the need for integrated, climate-resilient development pathways in the region.
Reaping what we sow: centering values in food systems transformations research
(2025) Care, O.; Zaehringer, Julie G.; Bernstein, Michael J.; Chapman, Mollie; Friis, Cecilie; Graham, Sonia; Haider, L. Jamila; Hernández-Morcillo, Mónica; Hoffmann, Harry; Kernecker, Maria Lee; Pitt, Hannah; Seufert, Verena; Care, O.; Stockholm Resilience Centre, Stockholm University, Albanovägen 28, 106 91, Stockholm, Sweden; Zaehringer, Julie G.; Wyss Academy for Nature, Kochergasse 4, 3012, Bern, Switzerland; Bernstein, Michael J.; AIT, Austrian Institute of Technology, Gieffengasse 4, 1210, Vienna, Austria; Chapman, Mollie; Transdisciplinarity Lab, Department of Environmental Systems Science, ETH Zurich, Universitaetstrasse 22, 8092, Zurich, Switzerland; Friis, Cecilie; Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen, Denmark; Graham, Sonia; Australian Centre for Culture, Environment, Society and Space, University of Wollongong, Northfields Ave, 2220, Wollongong, NSW, Australia; Haider, L. Jamila; Stockholm Resilience Centre, Stockholm University, Albanovägen 28, 106 91, Stockholm, Sweden; Hernández-Morcillo, Mónica; University for Sustainable Development, Alfred-Möller-Str. 1-Haus 11, 16225, Eberswalde, Germany; Hoffmann, Harry; TMG Research gGmbH, EUREF Campus 6-9, 10829, Berlin, Germany; Kernecker, Maria Lee; ZALF, Eberswalder Str. 84, 15374, Müncheberg, Germany; Pitt, Hannah; Cardiff University, Glamorgan Building, King Edward VII Avenue, CF10 3WA, Cardiff, Wales, UK; Seufert, Verena; Institute of Social Sciences in Agriculture, Department Sustainable Use of Natural Resources (430C), University of Hohenheim, Stuttgart, Germany
In many transdisciplinary research settings, a lack of attention to the values underpinning project aims can inhibit stakeholder engagement and ultimately slow or undermine project outcomes. As a research collective (The Careoperative), we have developed a set of four shared values through a facilitated visioning process, as central to the way we work together: care, reflexivity, inclusivity, and collectivity. In this paper, we explore the implications of a values-centered approach to collaboration in food system transformation research. The paper presents two cases that illustrate how researchers might approach centering values in practice. Where much research on food system transformation focuses on values of food system stakeholders, we contribute insights into the values of researchers in such transdisciplinary endeavors. Specifically, we argue that researchers working on sustainability transformations need to be better prepared to engage in such reflections and aspire to embody values aligned with the transformations they seek to research.