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| Author(s): |
Julia Natalia de Oliveira Mazoni
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química |
| Defense date: | 2008-09-26 |
| Examining board members: |
Theo Guenter Kieckbusch;
Maria Regina Wolf Maciel;
Paulo de Tarso Vieira e Rosa
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| Advisor: | Alvaro Bandeira Antunes de Azevedo; Paulo Mazzafera; Theo Guenter Kieckbusch |
| Abstract | |
Neem (Azadirachta indica A. Juss) is a tree that grows naturally in India and neem extracts are widely used in the traditional medicine as antiseptic, worm killer, contraceptive, medicinal soaps, shampoos and toothpastes and for the treatment of several health disorders. The main active component found in the seeds and in lesser amount in neem oil is azadirachtin, a tetranotriterpenoid with insecticide properties. This work evaluated the applicability of processes that use supercritical fluids on milled seeds of neem cultivated in the State of Pernambuco, Brazil, containing 1.05% of azadirachtin (determined by Soxhlet with ethanol) and 47,4% of oil (determined by Soxhlet with hexane). The operational pressures used were 150, 200, 250 bar at 50, 60 and 70ºC temperature (extraction runs with pure CO2) and pressures of 200 and 300 bar and temperatures of 50 and 60ºC (extraction runs with CO2+ethanol as co-solvent). The solubility of neem oil in supercritical CO2 increases with the increase of pressure and decreases when temperature increases. At 300 bar and 50ºC the solubility is 6,8 g of oil/kg of CO2. Runs with pure CO2 at 250 bar and 50ºC were able to remove 90% of the oil, but only 6.4% of azadirachtin from the seeds. Using ethanol as co-solvent improved the oil extraction in about 20% and boosted the recovery of azadirachtin 5 times. A two-step extraction run, at 50ºC and 200 bar using 1800 g of pure CO2 followed by 1500 g of CO2+10% ethanol produced an oil phase with 1,5% of azadirachtin. Runs using pure CO2 under cycling pressure varying between 100 and 200 bar, at 40 and 50ºC in order to inactivate naturally occurring molds in neem showed effective reduction of Aspergillus contamination in whole seeds (80% reduction), but inconclusive results for milled seeds. These results seems promising for the development of non-thermal inactivation treatments that are chemically non-aggressive to the products, use mild temperatures and pressures that can be considered moderate compared to HPT processes. (AU) | |