A Comprehensive Review of Pineapple Peel Extract as a Sustainable Engineering Material

Pineapple (Ananas comosus L.), a perennial herb belonging to the Bromeliaceae family, is one of the most important tropical and subtropical fruits worldwide, ranking third in global tropical fruit production after banana and citrus and contributing nearly 20% of total tropical fruit output. It is consumed fresh and widely processed into canned slices, jellies, pickles, jams, squashes, juice concentrates, and flavoring essences, and is well regarded for its rich nutritional profile, including minerals, vitamins, dietary fiber, and pronounced antioxidant activity. Despite this extensive utilization, processing residues—particularly pineapple peel (PP)—remain comparatively underexploited. Historically, research on pineapple waste has largely emphasized two major directions: the extraction of bromelain and the generation of value-added products such as ethanol, phenolic antioxidants, heavy metal adsorbents, organic acids, biogas, and fibers, typically through cost-effective approaches like fermentation and drying. This paper focuses explicitly on PP, considering it not merely as agro-industrial biomass but as a promising engineering material. It offers a comprehensive account of PP generation, its detailed physicochemical composition, and the principal extraction techniques used to recover high-value compounds, while examining how different pre-treatment strategies enhance extraction efficiency. Furthermore, the paper highlights the potential applications of PP-derived extracts and fractions in both biomedical and engineering sectors, underscoring their relevance beyond conventional waste disposal or low-value by-product utilization. Ultimately, the study aims to reframe PP as a versatile, high-potential engineering feedstock capable of contributing meaningfully to sustainable material development and supporting a more circular, resource-efficient bioeconomy.