Characterization and utilization of brewer’s spent yeast for sustainable packaging innovations

Background: The primary focus of this work is the valorization of brewer's spent yeast (BSY), a common by-product of beer production. Despite being traditionally utilized in animal feed, BSY remains rich in valuable nutrients, including proteins, fatty acids, vitamins, minerals, and textural and rheological compounds such as β glucans and mannoproteins, with potential applications in the food packaging production. The application of pre-treatments such as microfiltration and/or centrifugation, can certainly allow a concentration of compounds of interest and a removal of impurities. This study aimed to characterize for β-glucans, mannoproteins, fatty acids, and proteins content in BSY samples, which varied among each other based on the pre-treatment applied. Methods: In particular, BSY aliquots were filtered by a sieve (mesh F120) or washed by microfiltration/diafiltration protocol with ceramic membranes at different cut-off (DF2/MF 0.14μm; DF2/MF 1.4 μm) or through two cycles of centrifugation/resuspension(2CW). Analyzing the results, the pre-treatment applied affected the compositional profiles of the BSY samples. The most promising samples in terms of the targeted molecular content are the ones subjected to centrifugation/resuspension pre-treatments. Results: These samples exhibit higher mannoproteins and lower glucose content, and the highest β-glucans content at approximately 7%. This study highlights the broader implications of these findings for the development of sustainable packaging solutions in the food industry. Conclusions: By leveraging the unique molecular composition of BSY, particularly its rich content of mannoproteins and β-glucans, there exists significant potential to contribute to environmentally friendly packaging alternative. This aligns seamlessly with global initiatives promoting sustainability in food packaging technology, ensuring a more responsible and resource-efficient approach in addressing the increasing demands of the food industry.