Green Chemistry: essential oils from orange peel for industry, thanks to UniPi and CNR
“Recirculate” is the key word – as the word suggests – of circular economy: an economic and productive paradigm addressed to environmental sustainability, focused on the use or re-use of waste, sub-products, processing waste within new industrial processes. However, it is often not so easy to efficiently and beneficially transform waste into a resource.
An Italian research team has developed a promising technology for the re-use of food waste, recently earning the cover of the last 2016 issue of the Green Chemistry journal. The study was jointly carried out by the researchers of the Thermolab of the Department of Chemistry and Industrial Chemistry of the University of Pisa and the National Institute of Optics of the National Research Council (INO-CNR), along with academics from the University of Cagliari and the Istituto Tecnico Industriale Statale “Michele Giua” of Cagliari.
The researchers developed an innovative extracting process that allows to obtain products of high commercial interest from waste biomasses. In particular, thanks to the technologies developed, they obtained essential oils and pectin that can be used in cosmetics, perfume and food industries from orange peel. The study was conducted within a project funded by the Fund for Investments of Fundamental Research (FIRB) 2012 of the Ministry of Education, University and Research.
The study allowed to process biomasses through the joint action of microwaves and ultrasounds: in particular, the extractive processes from orange peels were activated with microwaves emitted by a coaxial dipole antenna located inside the biomass. Several configurations have been tested by the researchers, including a solventless microwave extraction and a hydrodistillation that involved the application of microwaves and ultrasounds at the same time. Both methods have produced good results in terms of yield, thus allowing a high energy saving with respect to conventional hydrodistillation methods.
The study showed that the most promising approach is the solventless one that, by using the water naturally contained in the orange peel, also allows for water saving with respect to traditional methods. Overall, these benefits make the study a useful source of innovative ideas for the valorisation of food waste through efficient processes from the technological, energetic and economic perspective.