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| Author(s): |
Renato Sano Coelho
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2011-08-23 |
| Examining board members: |
Ranulfo Monte Alegre;
Jonas Contiero;
Marta Cristina Teixeira Duarte
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| Advisor: | Ranulfo Monte Alegre |
| Abstract | |
There has been a growing interest on kojic acid since the discovery of its tyrosinase inhibiton properties, which make it useful for many different applications like dermal hyperpigmentation treatment, inhibition of fruits and vegetables enzymatic browning, antiinflamatory and analgesic drugs production, polymer productions, among others. The economical potential of kojic acid motivates researchers to develop more efficient and economical ways of producing it and therefore increase its commercial attractiveness. The present work focused on the study of the kojic acid fermentative production process in order to determine parameters that could help the development of more competitive production technologies. It also proposes the use of low cost raw materials with large availability in Brazil, since as glycerol and corn steep liquor. The selected species for the study was the Aspergillus flavus NRRL 626, which showed the highest growth rate, sporulation and kojic acid production. The selection of substrates pointed that glucose e glycerol were the best carbon sources and yeast extract and corn steep liquor were the best nitrogen sources for kojic acid production. Culture medium optimized through experimental designs with glucose as carbon source and corn steep liquor as nitrogen source allowed a productivity of 0,12 g kojic acid ¿ L-1 ¿ h-1 and a final concentration of 48 g ¿ L-1 after 22 days. The optimized medium containing glycerol as carbon source obtained maximum productivity of 0,13 g ¿ L-1 ¿ h-1 and 48 g kojic acid ¿ L-1 after 20 days of fermentation. Crude glycerol from biodiesel strongly inhibited koijc acid production and its use as carbon source reached the maximum concentration of 18 g kojic acid ¿ L-1 after 22 days of fermentation. Cultivation in a 5 L batch fermentor using glycerol and corn steep liquor showed excessive foam formation e wall adherence. Anti-solvent crystallization and active carbon clarification were successful techniques for recovery and purification of kojic acid produced (AU) | |