Title : Development of powdered foods with probiotic viability: Behaviour of starter cultures in dairy and soy-based beverages, microstructural changes, and rheological properties
Abstract:
In recent decades, Plant-Based Dairy Alternatives (PBDA) have gained prominence due to consumer preferences and sustainability concerns. Furthermore, the production of powdered foods is a viable alternative to increase shelf-life, and understanding how drying conditions influence the viability of Lactic Acid Bacteria (LAB) and rehydration properties is essential to obtain high-quality powders. In this sense, this work presents the main challenges in food engineering regarding fermentation, powder production, structural and rheological changes, and potential solutions. Initially, this study will demonstrate how LAB behaves in both dairy and soy-based substrates, showing the impact of fermentation time on physicochemical properties, antioxidant activity, and LAB viability. After the best fermentation conditions were obtained, the powders were produced using spray- and freeze-drying processes, evaluating the microparticle size and rheological properties, in addition to morphology visualisation using Scanning Electron Microscopy (SEM). Since rehydrated powders have difficulties in obtaining similar rheological properties of fresh beverages, the addition of natural thickeners is also discussed. Lastly, this research investigates the impact of shelf-life on LAB viability, powder characterisation, and how increase in moisture affects powder quality and stability. Overall, the current work offers valuable insights for the formulation of powdered foods, highlighting the complex relationships among the different drying processes and matrix compositions, and guiding future research on powdered products and rehydration properties.
