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

Pineapple (Ananas comosus L.), a prominent perennial herb of the Bromeliaceae family, stands as a globally cultivated tropical and subtropical fruit of significant economic importance. Ranking third in global tropical fruit production, it accounts for approximately 20 % of the total, following banana and citrus. Beyond fresh consumption, pineapple finds extensive use in various food products, including canned fruit, jellies, pickles, jams, squashes, juice concentrates, and essences. It is also recognized for its rich nutrient profile, encompassing minerals, vitamins, dietary fiber, and notable antioxidant activities. Despite its widespread utilization, the processing residues of pineapple, particularly the peel, have largely remained underexplored. Historically, researchers have concentrated on two primary applications for general pineapple waste: the extraction of bromelain and the production of substances like ethanol, phenolic antioxidants, heavy metal adsorbents, organic acids, biogas, and fibers. These endeavors often leverage cost-effective methods such as fermentation and drying. This paper focuses specifically on pineapple peel (PP), treating it not only as an agricultural residue but as a potential engineering material. It aims to give a clear, comprehensive overview of where PP is generated, its detailed physicochemical composition, and the different extraction techniques used to obtain valuable compounds from it. The discussion includes how various pre-treatment strategies influence and improve the efficiency of extracting these high-value constituents. The work also emphasizes the potential applications of PP extracts in both biomedical and engineering sectors, demonstrating that PP can serve purposes far beyond conventional waste disposal or low-value by-product use. In addition, the paper outlines the emerging role of PP extract as a novel engineering feedstock, envisioning its contribution to the design and development of sustainable materials. Overall, the study seeks to reposition PP from a discarded residue to a versatile, high-potential resource with wide-ranging and impactful applications.