This work innovatively merges engineered food structures with additive manufacturing technology to tailor food for different dysphagia levels using filamentous Fungus Aspergillus oryzae biomass through a co-axial 3D food printing process. In order to 3D print samples with different textures, calcium chloride (CaCl2) and calcium gluconolactate (Gluco) were tested at different concentrations alongside three alginate concentrations. The structural and morphological analysis of the printed samples was conducted before cooking, followed by texture analysis and the measurement of cutting strength on cooked samples. Dysphagia food level classification was measured following the International Dysphagia Diet Standardisation Initiative (IDDSI) guidelines. Results revealed that Gluco minimally altered texture but affected appearance, resulting in soft samples (hardness ≈ 1.3 N) with fibrous structures, while CaCl2 increased hardness (from ≈ 1 N to 4.68 N) through alginate-ion Ca2+ interaction. All samples passed the IDDSI test, confirming suitability for dysphagic individuals. This successfully engineered personalised food with tailored texture meeting nutritional requirements. 

Edible filamentous fungi, a source of mycoprotein, are one of the sustainable alternative protein. This study compares protein digestibility (DH%) and amino acid and mineral accessibility in Rhizopus oligosporus cultivated in oat flour (OatRO) or glucose media (GluRO) by using the INFOGEST in vitro digestion protocol. Fungal total amino acids was higher in GluRO (39.0 ± 1.1 % dw) than OatRO (21.8 ± 1.3 % dw) which was also the case for calcium and magnesium content. After completed gastrointestinal digestion, there were no significant differences between GluRO and OatRO regarding DH% (27.21 ± 10.4 % and 29.4 ± 0.5 %), however, GluRO provided significantly higher amino acid accessibility compared to OatRO (64.3 ± 1.6 % and 55.1 ± 3.1 %). Mineral accessibility of GluRO was for Ca: 37.9 ± 1.8 %, Zn: 9.3 ± 0.4 %, Fe: 38.2 ± 1.9 %, Mg: 66.5 ± 1.4 % and Cu: 24.7 ± 1.3 % and for OatRO; Ca: −40.2 ± 2.4 %, Zn: −4.13 ± 0.15 %, Fe:14.6 ± 1.6 %, Mg: 74.5 ± 3.1 %, and Cu: 55.95 ± 0.8 %. Despite the low phytic acid content, OatRO thus showed antinutrient properties with respect to calcium, and zinc, suggesting that oat-derived fungi had antinutrients other than phytic acid. This study hereby revealed that the cultivation substrate affect amino acid and mineral accessibility of filamentous fungi and calls for deeper evaluations of antinutrients in oat-derived fungi.

Since the first years of history, microbial fermentation products such as bread, wine, yogurt and vinegar have always been noteworthy regarding their nutritional and health effects. Similarly, mushrooms have been a valuable food product in point of both nutrition and medicine due to their rich chemical components. Alternatively, filamentous fungi, which can be easier to produce, play an active role in the synthesis of some bioactive compounds, which are also important for health, as well as being rich in protein content. Therefore, this review presents some important bioactive compounds (bioactive peptides, chitin/chitosan, β-glucan, gamma-aminobutyric acid, L-carnitine, ergosterol and fructooligosaccharides) synthesized by fungal strains and their health benefits. In addition, potential probiotic- and prebiotic fungi were researched to determine their effects on gut microbiota. The current uses of fungal based bioactive compounds for cancer treatment were also discussed. The use of fungal strains in the food industry, especially to develop innovative food production, has been seen as promising microorganisms in obtaining healthy and nutritious food.

Food systems have the potential to improve human health while contributing to environmental sustainability; however, they are currently endangering both. The current food system, which is often based on animal farming, is responsible for global greenhouse gas emissions, and increases the incidence of, and mortality from, non-communicable diseases. Providing the growing global population with healthy food from sustainable systems is an urgent requirement. Microbial fermentation is expected to play a significant role in the transition to sustainable and healthy food systems. Microorganisms, such as edible filamentous fungi, can be a part of the solution. The versatility of filamentous fungi enables them to grow on a variety of substrates in submerged or solid-state fermentation, which minimizes substrate limitations, as well as exhaustive land and water requirements in the cultivation process. In this thesis, the potential of filamentous fungi in the production of sustainable and healthy food, and optimization of fungal biomass production through submerged fermentation on synthetic glucose- and oat-based media, were studied. Additionally, scale-up, sensory characteristics, and nutritional profiles were assessed.

In order to evaluate the production of sustainable and healthy food from filamentous fungi, Aspergillus oryzae, a fungus that is commonly used in food production, was cultivated on oat flour in a pilot-scale airlift bioreactor. The nutrient-rich fungal biomass obtained by increasing the protein content was characterized by an improved ratio of essential amino and fatty acids, and an increase in dietary fiber, minerals, and vitamins. Fungal biomass was converted to Burger patties with minimal downstream processing, which were then subjected to sensory evaluation using an untrained panel. Inspired by the ability of filamentous fungi to produce different bioactive compounds, four strains of edible filamentous fungi commercially used in food production, namely, Aspergillus oryzae, Rhizopus oryzae, Neurospora intermedia, and Rhizopus oligosporus, were cultivated in a semi-synthetic medium using submerged fermentation to screen for the synthesis of the bioactive compound L-carnitine. The formation of L-carnitine can be enhanced by modulating various factors, such as the fungal strain, cultivation time, and the presence of yeast extract. Aspergillus oryzae was found to have a much greater potential for L-carnitine production than Rhizopus sp and Neurospora intermedia.

In terms of moving towards a sustainable and healthy food supply system, this thesis might contribute not only industrially but also in terms of policy development.

Resource dependency of food production is aggravated when food is wasted. In Sweden, it is estimated that 37% of the total bread waste is generated at the household level. This work aimed to assess whether fermentation using edible filamentous fungi at households can provide a solution to valorize leftover bread in the production of fungi-based food for consumption. Bread was fermented in household and laboratory conditions with Neurospora intermedia and Rhizopus oligosporus. The results show that bread can be successfully and easily fermented at households, without signs of microbial contamination even though the conditions were not sterile. Fermentation at the household resulted in higher protein, fat and fiber content as well as greater starch reduction compared to the samples fermented under laboratory conditions. Household engagement in bread fermentation will likely depend on values that motivate reusing leftover bread. Perceived values that are expected to motivate engagement vary across individuals, but may include improved nutritional benefits, food waste prevention, convenience, responsibilities, and being part of sustainable societies and actions.

Fermentation and bioprocesses in which various metabolites from food to pharmaceutics are produced are constantly evolving. This section is devoted to contamination risks and their eliminations, media preparation, decontamination, and sterilization methods for such processes. For contamination, sources of microbial contaminations and decontamination (physical and chemical) practices are discussed. In addition, sterilization methods (heat, filtration, chemical, and radiation) that are applied for the removal of microorganisms from small-scale to large-scale instruments, gases, and liquids are explained. In the preparation of the media, the batching area, developed equipment, and methods for large-scale reactors are mentioned. In summary, the preparation and sterilization of the media in bioprocesses from laboratory-scale reactors to industrial-scale reactors are evaluated.

Fermentation can be a powerful tool for developing new sustainable foods with increased nutritional value and fermented microbial biomass derived from filamentous fungi is a promising example. This study investigates the nutritional profile of edible Aspergillus oryzae biomass produced under submerged fermentation (SmF) using oat flour as a substrate. The fermentation occurred in a 1m³ airlift bioreactor during 48 h at 35 °C and the nutritional profile of the produced fungal biomass in terms of amino acids, fatty acids, minerals (Fe, Zn, Cu, Mn), vitamins (E, D₂), and dietary fiber was compared to oat flour as well as pure fungal biomass grown on semi-synthetic medium. The total amount of amino acids increased from 11% per dry weight (dw) in oat flour to 23.5% dw in oat fungal biomass with an improved relative ratio of essential amino acids (0.37 to 0.42). An increase in dietary fibers, minerals (Fe, Zn, Cu), vitamin E, as well as vitamin D₂ were also obtained in the oat fungal biomass compared to oat flour. Moreover, the short chain omega-3 α-linolenic acid (ALA) and omega-6 linoleic acid (LA) values increased from 0.6 to 8.4 and 21.7 to 68.4 (mg/g dry weight sample), respectively, in oat fungal biomass. The results indicate that fungal biomass grown on oat flour could have a potential application in the food industry as a nutritious source for a wide variety of products.

New food sources are explored to provide food security in sustainable ways. The submerged fermentation of edible filamentous fungi is a promising strategy to provide nutritious and affordable food that is expected to have a low environmental impact. The aim of the current study was to assess the novel use of Aspergillus oryzae cultivated in submerged fermentation on oat flour as a source for food products that do not undergo secondary fermentation or significant downstream processing. The fungus was cultivated in a pilot-scale airlift bioreactor, and the biomass concentration and protein content of the biomass were assessed. A tasting with an untrained panel assessed consumer preferences regarding the taste and texture of minimally processed vegetarian and vegan burger patties made from the biomass, and how the patties fared against established meat-alternative-based patties. The cultivation of Aspergillus oryzae resulted in a yield of 6 g/L dry biomass with a protein content of 37% on a dry weight basis. The taste and texture of the minimally processed fungal burger patties were to the liking of some participants. This was also reflected in diverse feedback provided by the participants. The cultivation of the fungus on oat flour and its utilization in developing burger patties shows its promising potential for the production of nutritious food. The applications of the fungus can be further developed by exploring other favorable ways to texture and season this relatively new functional food source to the preferences of consumers. 

The edible filamentous fungi are hot candidate for future supply of functional food and feed with e.g. protein, essential amino acids, and compounds with immunostimulant activity. L-carnitine that plays a crucial role in energy metabolism represents a functional compound normally produced by Zygomycetes filamentous fungus Rhizopus oligosporus in solid-state fermentation. The present study provides the first insights on production of L-carnitine-enriched edible fungal biomass through submerged cultivation of several Ascomycetes and Zygomycetes including Aspergillus oryzae, Neurospora intermedia, Rhizopus oryzae, and Rhizopus oligosporus. A. oryzae with 3 mg L-carnitine yield per gram of fungal biomass, indicates great potential on production of this bioactive compound which is remarkably higher than the other tested fungi in this work and also previous studies. In addition to fungal strain, other factors such as cultivation time and presence of yeast extract were found to play a role. Further studies on submerged growth optimization of A. oryzae in both high-quality recipes and in medium based on low-value substrates are proposed in order to clarify its potential for production of L-carnitine-enriched fungal biomass.