Integrated valorisation of protein- and lignin-rich streams from brewers’ spent grain through an electrified biorefinery approach for active food packaging applications

This work highlights the potential of valorising brewing industry side-streams for the development of bio-based food packaging materials. Brewers’ spent grain (BSG) was pre-treated using a non-thermal air-bubble plasma reactor as part of an electrified biorefinery, followed by enzymatic hydrolysis, enabling the separation of protein-, lignin-, and sugar-rich fractions. The residual solids (BSG-RS) were explored through three film-forming strategies, with the film formulation using the recovered protein concentrate emerging as the most efficient process. This route was further optimised by incorporating bacterial cellulose nanostructures, produced from the sugar-rich hydrolysate, as a reinforcing agent. Delignification of BSG-RS enabled the recovery of a lignin-rich fraction, which was used to enhance film functionality by testing two lignin formulations, namely alkaline lignin (AL) and lignin particles (LPs). The developed films exhibited excellent light-barrier properties (T600 < 2.3 %) and high antioxidant activity (>38.2 % inhibition). Structural characterization (scanning electron microscopy, thermogravimetric analysis, and X-ray diffraction) demonstrated distinct morphology-dependent interactions of the AL and LPs within the film matrix, leading to opposite effects on structural organisation and thermal stability. When applied to refrigerated salmon fillet, selected formulations performed comparably to PVC and extended shelf life by up to 4 days. Overall, the proposed approach effectively valorised all derived fractions of the BSG-based biorefinery towards functional food packaging, contributing to the sustainable utilisation of industrial side-streams into eco-friendly alternatives to conventional packaging.

Palavras-chave

Brewers' spent grain Bacterial cellulose Lignin Protein Food packaging

URI

http://hdl.handle.net/10198/36930

Citação

Margioulas, Christos; Sarafidou, Mirva; Colucci, Giovana; Santamaria-Echart, Arantzazu; Argeiti, Chrysanthi; Paramithiotis, Spiros; Tsironi, Theofania; Koutinas, Apostolis; Barreiro, Filomena; Filippi, Katiana (2026). Integrated valorisation of protein- and lignin-rich streams from brewers’ spent grain through an electrified biorefinery approach for active food packaging applications. Food Hydrocolloids. ISSN 0268-005X. 180, p. 1-15