Recently, plant-based food has become important in the global food market. The increasing demand for plant-based food is a consequence of the increase in both environmental awareness and care for animal welfare as well as the changes in nutritional recommendations. Therefore, food producers are concentrating on fulfilling consumer needs by creating alternatives to animal-based products with comparable nutritional and sensory qualities but from plant-based sources. One promising trend is the production of plant-based fish. Thus, this work aimed to summarize the possibilities of creating plant-based fish analogs, including a review of alternatives to fish products currently available on the market and the possible use of the various ingredients to produce plant-based fish analogs like fillets, slices, as well as sticks, or burgers. Furthermore, the plant-based ingredients were characterized for potential use in fish analogs production. Additionally, the study includes technologies used for plant-based fish analogs production, e.g., texturization, 3D and 4D printing, electrospinning, etc. Furthermore, future perspectives were given considering the challenges and limitations in this range.

Food byproduct streams can potentially be transformed into value-added products such as microbial lipids in bioprocesses based on the non-conventional Yarrowia yeast. The effect of culture conditions of Y. lipolytica KKP 379 wild strain in waste media on the efficiency of lipid accumulation, fatty acid composition, presence of selected sterols, yield and elemental composition of biomass has been studied. Batch and fed-batch bioreactor cultures were carried out in media with molasses hydrolysate (MH) and post-frying rapeseed oil. It was determined that biomass grown in MH contained more minerals than in medium with rapeseed post-frying oil. Considering the PDSC study, the Tmax of oxidation induction ranged from 10.04–26.36 min for the analyzed samples. The biomass from fed-batch cultures with MH had the highest total sterol content (68.40 mg/goil), dominated by ergosterol at 60.16 mg/g. Feeding with post-frying rapeseed oil with new doses of mineral medium promoted maintaining the cellular lipid content at a high level (30.75–31.73%) for 50 h, with maximum yield at 37.50%. The results of the experiment showed that the cellular lipid accumulation efficiency of Y. lipolytica yeast and the content of sterols in the cell membrane can be manipulated by selecting waste substrates and culture mode.