Change in stability and characteristics of different sunflower press cake mixtures during fermentation with Lactiplantibacillus plantarum

Abstract: Food's impact on the climate is getting more awareness, leading to an interest in finding possible solutions. One such is to use waste products to create new products. Sunflower press cake (SFPC) is a waste product from sunflower oil production with great potential because of its high protein content. The nutritional content, as well as its physicochemical properties, are affected by the source, for example, if the seeds are hulled or dehulled, as well as the pressing method during oil extraction. Together with whey, a waste product from cheese production, SFPC has the possibility of being a balanced nutritional food product. To increase the nutritional bioavailability and to create tasty food, the aim of this project was to ferment sunflower press cake dispersions. The addition of whey and homogenisation was investigated by analysing the pH change during fermentation, the viscosity before and after fermentation and the physical stability before and after fermentation. The results show differences between the SFPC where the dehulled and cold-pressed ones had the highest protein content and lowest insoluble fibre content. The solvent-extracted press-cake had the lowest dry matter and fat content. The fermentation with the cold-pressed and hulled cake led to the lowest pH and it had the shortest lag phase. It was also the most appetising looking, being beige while the others were brown. The methods showed whey affects both the stability and the fermentation, mainly by decreasing the pH further. The homogenisation influenced the stability, but it was not conclusive. In the future, it is recommended to try another lactic acid bacteria to see if it is possible to find a more suitable one. It is also recommended to analyse if the cold-pressing or dehullisation are affecting the results the most.