Biorefinery of waste orange peel

• Published in: Critical reviews in biotechnology 2010-03, Vol.30 (1), p.63-69
• Main Authors: Ángel Siles López, José, Li, Qiang, Thompson, Ian P.
• Format: Article
• Language: English
• Subjects: bioethanol; Biofuels; Biological and medical sciences; Biomass; Biorefinery; Biotechnology; Citrus sinensis - chemistry; D-limonene; Fundamental and applied biological sciences. Psychology; methane; pectic enzymes; pectin; Refuse Disposal - methods; singe cell protein; waste orange peel; Waste Products - analysis
• ISSN: 0738-8551; 1549-7801
• DOI: 10.3109/07388550903425201

Up to comparatively recently orange peel and the associated residual remnants of membranes resulting from juice extraction represented a significant disposal problem, especially in those regions where orange cultivation is a major industry. However, recent research has demonstrated that orange peel waste represents a potentially valuable resource that can be developed into high value products. These developments are critically reviewed in this article. This includes a summary of the chemical composition of the substrate and an assessment of the range of applications in which the peel is deployed. Utilization as a substrate to produce animal feed, fertilizer, essential oils, pectin, ethanol, methane, industrial enzymes, and single cell protein is discussed. The applications described together with those that will no doubt be developed in the future, represent great opportunities to harness the economical benefit of this agro-industrial waste and to develop even more efficient and sustainable systems. A scheme of integrated utilization of orange peel in a biorefinery approach is discussed together with some prediction of further necessary research.