Pine needles as a sustainable bioresource for agro-food industry

Recently, the interest in renewable plant-derived resources for the agro-food sector has significantly increased as industries seek green and sustainable bioprocess substrates. Pine needles (PN) are produced in large quantities across temperate and subtropical regions yet remain comparatively underexplored despite their cultural and medicinal uses. This review examines PN as a bioresource, focusing on botanical diversity, physicochemical composition (including 15-30% hemicellulose, up to 43% lignin and up to 60% cellulose), and secondary metabolite profiles. Particular attention is given to bioactive constituents such as phenolics (ranging between 9.8-14.1 mg GAE/g dried needles), flavonoids (ranging between 3.3-7.2 mg RE/g dried needles), and essential oils (reaching up to 0.8%, with 71 compounds identified in some species), along with relevance to food preservation, human nutrition, and health. The review evaluates bioprocessing approaches for saccharification and fermentation of PN lignocellulose and their potential integration into circular agro-food systems. This review comprehensively evaluates pine needles across different species, valorization in the food industry, highlighting the foremost knowledge in this domain. Despite promising opportunities, challenges remain, including regulatory guidelines, limited exploration in food applications and the recalcitrance of lignocellulosic biomass. By consolidating diverse research fields, the work establishes PN within future sustainable valorization frameworks for food and agricultural applications.