The increasing demand for flavors in the world market requires new strategies for obtaining these compounds which can be produced via fermentation processes using low cost substrates such as agroindustrial residues. This turns out to be a viable process and the aroma compounds generated are classified as natural. Large volumes of waste in the form of bagasse, husks, kernels or seeds including from the processing of fruit pulp are generated and these can be used as substrates in these fermentations. Thus the main purpose of this work was to use agro-industrial residues for the production of volatile aroma compounds by fermentation processes. In this regard, we investigated the potential of the production of volatile compounds by submerged fermentation using guava, passion fruit and umbu processing waste as substrates using endophytic microorganisms isolated from guava, passion fruit and umbu as well as by using the pure cultures (Aspergillus niger, Kluyveromyces marxianus and Kluyveromyces lactis) to produce volatile compounds characteristic of fruity or floral aroma. Initially the fruit pulp and wastes from the processing of guava, passion fruit and umbu were chemically characterized (moisture, ash, fiber, proteins, lipids, sugars, titratable acidity, Aw, pH and soluble solids). Fermentation with different microorganisms in synthetic medium was performed and the fermented products analyzed for aroma note. From the results of this sensory analysis, the guava residue and the yeast Kluyveromyces lactis were selected since these constituents in the medium produced fruity and floral aromas. The volatile compounds produced were captured by two headspace techniques (SPME and Purge & Trap) and analyzed in a system of gas chromatography coupled to mass spectrometry. Sixty-two microorganisms were isolated and out of these six were selected. The fermented products were analyzed for pH, soluble solids and reducing sugars as well as to establish the kinetics of the fermentation process at every 24 hours for five days. The main aroma descriptors in the fermented products were fruity, honey, fruity green, plum, guava, banana and alcohol type notes. Forty-three volatile compounds were detected in the fermented product obtained by using the Guava residue in the medium. Among the compounds identified were: Ò {caryophyllene, 2-phenylethyl acetate, × n- humulene, bisabolene, humulene, 3-methyl butanol, bergamoteno, × n-cadinene, caryophyllene oxide and 2-phenylethanol. The production of volatile compounds was quite rapid and in most cases, this production occurred on the first day of fermentation and had achieved its maximum concentration between 24-48h of fermentation. According to the response surface method analysis, the conditions of the manufacturing process were optimized. Increased production of 2- phenylethyl acetate was achieved at concentrations varying from 25 and 35g/L of yeast extract, 40 to 60 g/L glucose. Ò-caryophyllene was obtained at concentrations varying between 120 and 140g/L of guava waste, and an agitation performed between 160 and 180 rpm. The production of 2-phenylethanol was obtained at agitation varying from 228rpm and 5g/L glucose. From these optimized conditions, scale-up of fermentation was performed in a bioreactor wherein 6 times larger concentration of 2-phenylethanol and Ò-caryophyllene compounds, and 1.5 times higher concentration of 2-phenylethyl acetate were obtained. This study reveals that guava residue can be used to produce aroma compounds of great importance for the flavor and fragrance industry, the compounds being 2-phenylethyl acetate, 2-phenylethanol and Ò -caryophyllene. / A crescente demanda de aromas no mercado mundial exige novas estrategias de obtencao desses compostos. A obtencao via processos fermentativos utilizando substratos de baixo custo e uma alternativa economicamente viavel e o aroma gerado e considerado como natural. Grandes volumes de residuos na forma de bagacos, cascas, carocos ou sementes sao gerados pelo processamento de frutas, e estes podem ser utilizados como substratos nesses processos fermentativos. Diante desse contexto, esse trabalho teve como principal finalidade utilizar residuos agroindustriais para a producao de compostos volateis de aroma atraves da fermentacao submersa. Neste sentido, foi verificada a potencialidade da producao de compostos volateis atraves da fermentacao submersa utilizando residuos de goiaba, maracuja e umbu como substratos utilizando microrganismos endofitos da goiaba, maracuja e umbu de cultura puras (Aspergillus niger, Kluyveromyces marxianus e Kluyveromyces lactis) para produzir compostos volateis de aroma frutal ou floral. Inicialmente a polpa e os residuos de goiaba, maracuja e umbu foram caracterizados quimicamente (umidade, cinzas, fibras, proteinas, lipideos, acucares, acidez titulavel, Aw, pH e solidos soluveis). Foram realizadas fermentacoes com os diferentes microrganismos em meio sintetico, onde os produtos fermentados foram analisados sensorialmente. A partir dos resultados obtidos da analise sensorial, o residuo de goiaba e a levedura Kluyveromyces lactis foram selecionados uma vez que estes apresentaram a melhor capacidade de producao de aromas. Os compostos volateis produzidos foram capturados por duas tecnicas de headspace (MEFS e Purge & Trap) e analisados por cromatografia gasosa acoplada a espectrometria de massas. Foram isolados 62 microrganismos, dentre estes seis foram selecionados e os produtos fermentados foram analisados por cromatografia gasosa como tambem as caracteristicas de pH, solidos soluveis e acucar redutor para estabelecer a cinetica do processo fermentativo a cada 24h durante cinco dias. As principais descricoes de aroma para o fermentado de residuo de goiaba foram frutal, mel, fruta verde, ameixa, goiabada, banana, fermento e alcool. Foram detectados 43 compostos volateis no produto fermentado obtido pelo uso do residuo de goiaba. Dentre os compostos identificados destacam-se: Ò-cariofileno, acetato de 2-feniletil, ×-humuleno, bisaboleno, humuleno, 3-metil butanol, bergamoteno, ×-cadineno, oxido de cariofileno e 2-feniletanol. A producao dos compostos volateis foi bastante rapida, e na maioria dos casos, essa producao aconteceu a partir do primeiro dia de fermentacao e teve o seu maximo entre 24-48h de fermentacao. Segundo a analise da superficie de resposta, o processo de producao foi otimizado, onde a maior producao do acetato de 2-feniletil foi obtida em concentracoes entre 25 a 35g/L de extrato de levedura, entre 40 a 60 g/L de glicose; do Ò-cariofileno foi obtido em concentracoes entre 120 a 140g/L de residuo de goiaba, e agitacao entre 160 e 180 rpm enquanto a producao do 2-feniletanol foi obtida na agitacao entre 228rpm e 5g/L de glicose. A partir dessas condicoes otimizadas foi possivel realizar um escalonamento da producao desses compostos no biorreator e foi possivel obter uma producao 6 vezes maior para os compostos 2-feniletanol e Ò-cariofileno, e 1,5 vezes para o acetato de 2-feniletil. Desta forma, neste trabalho verifica-se que o residuo de goiaba e leveduras isoladas de frutas podem ser utilizados para produzir compostos de aroma de grande importancia para a industria de aromas e fragrancias, como o acetato de 2-feniletanol, o 2-feniletanol e o Ò-cariofileno.
| Identifer | oai:union.ndltd.org:IBICT/oai:ri.ufs.br:riufs/3305 |
| Date | 28 February 2014 |
| Creators | Galvão, Mércia de Sousa |
| Contributors | Narain, Narendra |
| Publisher | Pós-Graduação em Biotecnologia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFS, instname:Universidade Federal de Sergipe, instacron:UFS |
| Rights | info:eu-repo/semantics/openAccess |
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