Background: Brewer’s spent grain is one of the most abundant by-products of the brewing industry and is rich in various bioactive compounds (phenolic acids, insoluble dietary fiber and proteins). While at the present brewer’s spent grain is mainly used as animal feed its rich nutritional content makes it an interesting alternative for food applications. Scope and approach: As the range of applications of the bioactive compounds extracted from by-products has been growing in recent years, there is the need to obtain and characterize these bioactive compounds. Extraction methods (supercritical carbon dioxide, autohydrolysis, alkaline hydrolysis, solvent extraction, ultrasound assisted extraction, dilute acid hydrolysis, enzymatic hydrolysis, microwave assisted extraction) have been developed and are always being subjected to new approaches to allow better extraction yields of the bioactive compounds. Key findings and conclusions: This review aims to provide a better understanding of the current advantages and limitations of brewer’s spent grain extraction processes and to provide a background of brewer’s spent grain composition and applications.

Textile dyeing is known to have major environmental concerns, especially with the high use of toxic chemicals. The use of alternatives such as natural dyes rich in phenolic compounds has become extremely appealing in order to move towards a more sustainable circular economy. Phenolic dyes have the potential to functionalize textile fabrics with properties such as antimicrobial, antioxidant, and UV protection. Wastes/residues from the agri-food industries stand out as highly attractive sources of these compounds, with several by-products showing promising results in textile dyeing through the implementation of more sustainable and eco-friendly processes. This review presents an up-to-date exploration of the sources of phenolic compounds used in the textile industry over the past two decades, with a primary focus on the functional properties they provide to different fabrics. The research highlights a surge in interest in this theme since 2017, accentuating a noticeable upward trend. Throughout this review, emphasis is given to by-products from the agri-food industry as the sources of these compounds. The reviewed papers lay the foundation for future research, paving the way for exploring the potential of raw materials and by-products in the creation of functional and smart textiles.

Correction for ‘Bioactive extracts from brewer's spent grain’ by Teresa Bonifácio-Lopes et al., Food Funct., 2020, 11, 8963–8977, DOI: 10.1039/D0FO01426E.

Pterospartum tridentatum (L.) Willk. (carqueja) is widely used in traditional medicine and culinary practices in the Iberian Peninsula; however, most studies have focused on its flowers, while its stems remain largely unexplored, despite representing a significant proportion of the plant biomass. This study aimed to evaluate the potential of P. tridentatum stems as a source of bioactive compounds using different extraction methodologies. Aqueous, hydroethanolic, ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were applied, and the resulting extracts were characterized in terms of their extraction yield, protein and carbohydrate content, phenolic composition, antioxidant capacity, antimicrobial activity, and cytotoxicity in HaCaT and Caco-2 cell lines. Phenolic profiling by LC-ESI-QqTOF-HRMS tentatively identified 37 compounds, mainly corresponding to flavonoid and isoflavonoid glycosides, with genistein derivatives representing the dominant constituents across all extracts. Although extraction yields differed among methods, phenolic profiles were broadly similar. UAE and PLE extracts showed slightly higher antioxidant activity, while antimicrobial activity was limited, with only moderate inhibition observed against Staphylococcus epidermidis and Malassezia furfur. Additionally, cytotoxicity assays indicated low toxicity. Overall, the results demonstrate that P. tridentatum stems represent a promising yet underutilized biomass source of phenolic compounds with antioxidant potential and low cytotoxicity under the tested in vitro conditions.