Proposals for the residues recovery: Orange waste as raw material for new products

The production of orange juice on an industrial level leads to a considerable quantity of solid and liquid residue (around 8-20 million tons y(-1) globally), which is still considered as waste or used as a complement in agriculture. In general, orange residues have no economic value, even though their composition is rich in soluble sugars, cellulose, hemicellulose, pectin and essential oils that could form the basis of several industrial processes. In this study, information was collected on the technological potential of the solid and liquid residues generated in the processing of orange juice. Possible applications include human consumption, fertilizer, animal feed, charcoal, adsorption of chemical compounds, bio-oil production and extraction of essential oils and pectin. In this preliminary study, alternatives are proposed for the minimization and recovery of solid and liquid residues generated in the production of orange juice with a view to the implantation of industrial plants which can reuse this material, in order to add value to this solid and liquid waste and provide environmental benefits. The alternatives were proposed based on information and data available in the literature and the concepts of clean technologies. (C) 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.