Supercritical fluid extraction of Eichhornia crassipes
Autor(a) principal: | |
---|---|
Data de Publicação: | 2014 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/14299 |
Resumo: | The aim of this thesis was to evaluate the potential of Eichhorina crassipes harvested from Pateira de Fermentelos, Águeda, as a source of phytosterols, namely stigmasterol, by Soxhlet and supercritical fluid extraction. Supercritical extractions were used in this thesis as an alternative to conventional techniques that use organic solvents, allowing the assessment of both extractions in terms of concentration, yield and selectivity for stigmasterol. In both cases chemical evaluation was carried out using different techniques: GCMS, total phenol content and antioxidant activity. With this intent, an experimental work plan was established. First, the biomass was harvested and divided in its different morphological parts, roots, stalks, leaves and flowers. Secondly, soxhlet extractions with dichloromethane were performed and the extracts analyzed by GC-MS. This step revealed a strong stigmasterol concentration in stalks and leaves (15.0% and 13.5%; mg/100mgextract) and a total yield value of 1.12, 2.65, 3.30 and 4.45 wt.% respectively. Thirdly, solid liquid extractions were performed and total phenolic and antioxidant activity were assessed, revealing that leaves possessed higher phenolic content and antioxidant activity than all other morphological parts. Finally, supercritical fluid extractions (SFE) were performed. These were divided in two stages. In the preliminary stage, a mixture of all parts where submitted to extraction revealing a lower overall extraction yield but higher stigmasterol concentration (31% mg/100mgextract). The second phase of SFE was performed in order to obtain the overall extraction curves (OEC). These were performed with a biomass mixture that revealed a higher stigmasterol content, namely stalks and leaves. These extractions demonstrated that temperature had little effect on the total yield, that the optimal time of extraction was of one hour and the maximum stigmasterol concentration was achieved after two hours of extraction. Regarding the modeling of the extraction curves, internal diffusion revealed to be the dominant mass transfer mechanism. In sum, these results show that supercritical extraction of E. crassipes biomass can become a promising extraction technology, generating rich stigmasterol extracts, opening a possible window for its commercial implementation. |
id |
RCAP_b190074a0ee4e696a0df2f248f6f868b |
---|---|
oai_identifier_str |
oai:ria.ua.pt:10773/14299 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Supercritical fluid extraction of Eichhornia crassipesEngenharia químicaEsteróis - Plantas aquáticasFenóisExtracção supercríticaCromatografia gasosaEspectroscopia de massaAntioxidantesEichhornia crassipesThe aim of this thesis was to evaluate the potential of Eichhorina crassipes harvested from Pateira de Fermentelos, Águeda, as a source of phytosterols, namely stigmasterol, by Soxhlet and supercritical fluid extraction. Supercritical extractions were used in this thesis as an alternative to conventional techniques that use organic solvents, allowing the assessment of both extractions in terms of concentration, yield and selectivity for stigmasterol. In both cases chemical evaluation was carried out using different techniques: GCMS, total phenol content and antioxidant activity. With this intent, an experimental work plan was established. First, the biomass was harvested and divided in its different morphological parts, roots, stalks, leaves and flowers. Secondly, soxhlet extractions with dichloromethane were performed and the extracts analyzed by GC-MS. This step revealed a strong stigmasterol concentration in stalks and leaves (15.0% and 13.5%; mg/100mgextract) and a total yield value of 1.12, 2.65, 3.30 and 4.45 wt.% respectively. Thirdly, solid liquid extractions were performed and total phenolic and antioxidant activity were assessed, revealing that leaves possessed higher phenolic content and antioxidant activity than all other morphological parts. Finally, supercritical fluid extractions (SFE) were performed. These were divided in two stages. In the preliminary stage, a mixture of all parts where submitted to extraction revealing a lower overall extraction yield but higher stigmasterol concentration (31% mg/100mgextract). The second phase of SFE was performed in order to obtain the overall extraction curves (OEC). These were performed with a biomass mixture that revealed a higher stigmasterol content, namely stalks and leaves. These extractions demonstrated that temperature had little effect on the total yield, that the optimal time of extraction was of one hour and the maximum stigmasterol concentration was achieved after two hours of extraction. Regarding the modeling of the extraction curves, internal diffusion revealed to be the dominant mass transfer mechanism. In sum, these results show that supercritical extraction of E. crassipes biomass can become a promising extraction technology, generating rich stigmasterol extracts, opening a possible window for its commercial implementation.Nesta dissertação pretendeu-se avaliar o potencial da Eichhornia crassipes colhida na Pateira de Fermentelos, Águeda, como uma possível fonte de fitoesteróis, nomeadamente estigmasterol, extraídos com recurso a Soxhlet com diclorometano e usando dióxido de carbono supercrítico. A extração supercrítica surge nesta tese como alternativa a extrações convencionais com solventes orgânicos, pretendendo-se avaliar o seu potencial em termos de capacidade e seletividade para o estigmasterol. Em ambos os casos, os extratos obtidos foram caracterizados por diferentes técnicas: GC-MS, quantificação de fenólicos totais e atividade antioxidante. Com este objetivo, foi elaborado um plano experimental de trabalho. Primeiramente, a planta colhida, separada nas suas diferentes partes morfológicas (raiz, caule, folha e flor), seca e triturada. Em segundo lugar, as extrações Soxhlet foram efetuadas e os extratos analisados por GC-MS. Estas extrações revelaram uma concentração elevada de estigmasterol nos caules e folhas (15.0% e 13.5%; mg/100mgextract) e um rendimento total de 1.12, 2.65, 3.30 e 4.45 wt.% para raízes, caules, folhas e flores, respectivamente. De seguida, foram realizadas extrações sólido-líquido com misturas metanol:água e os extratos analisados relativamente à composição em fenólicos totais e atividade antioxidante. Estes resultados evidenciaram que, de todas as partes morfológicas da planta, as folhas são as que possuem uma maior quantidade de fenólicos totais assim como maior atividade antioxidante. Por fim, foram conduzidas várias extrações supercríticas. Começou-se por alguns ensaios preliminares, usando uma mistura de todas as partes da planta, que mostraram um baixo rendimento total, mas uma elevada concentração em estigmasterol (31 mg/100mgextract). A segunda etapa de extrações supercríticas visou a medição de curvas de extração, usando as partes morfológicas da biomassa que apresentavam maior concentração de estigmasterol, ou seja, caules e folhas. Estas extrações revelaram que a influência da temperatura é praticamente desprezável, que o tempo ótimo de extração é de cerca de 1 h, mas que a concentração máxima de estigmasterol se obtém ao fim de duas horas. Em termos de modelação das curvas cumulativas de extração, mostrouse que o processo supercrítico é predominantemente controlado por difusão interna. Em conclusão, os resultados obtidos demonstraram que a extração supercrítica de E. crassipes pode ser considerada uma tecnologia promissora para a produção de extratos enriquecidos em estigmasterol, podendo desta forma viabilizar uma implementação comercial.Universidade de Aveiro2018-07-20T14:00:49Z2014-07-28T00:00:00Z2014-07-282016-07-28T14:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10773/14299TID:201592142engSilva, Rui Pedro Fonseca Ferreira dainfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:26:07Zoai:ria.ua.pt:10773/14299Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T02:49:54.310571Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Supercritical fluid extraction of Eichhornia crassipes |
title |
Supercritical fluid extraction of Eichhornia crassipes |
spellingShingle |
Supercritical fluid extraction of Eichhornia crassipes Silva, Rui Pedro Fonseca Ferreira da Engenharia química Esteróis - Plantas aquáticas Fenóis Extracção supercrítica Cromatografia gasosa Espectroscopia de massa Antioxidantes Eichhornia crassipes |
title_short |
Supercritical fluid extraction of Eichhornia crassipes |
title_full |
Supercritical fluid extraction of Eichhornia crassipes |
title_fullStr |
Supercritical fluid extraction of Eichhornia crassipes |
title_full_unstemmed |
Supercritical fluid extraction of Eichhornia crassipes |
title_sort |
Supercritical fluid extraction of Eichhornia crassipes |
author |
Silva, Rui Pedro Fonseca Ferreira da |
author_facet |
Silva, Rui Pedro Fonseca Ferreira da |
author_role |
author |
dc.contributor.author.fl_str_mv |
Silva, Rui Pedro Fonseca Ferreira da |
dc.subject.por.fl_str_mv |
Engenharia química Esteróis - Plantas aquáticas Fenóis Extracção supercrítica Cromatografia gasosa Espectroscopia de massa Antioxidantes Eichhornia crassipes |
topic |
Engenharia química Esteróis - Plantas aquáticas Fenóis Extracção supercrítica Cromatografia gasosa Espectroscopia de massa Antioxidantes Eichhornia crassipes |
description |
The aim of this thesis was to evaluate the potential of Eichhorina crassipes harvested from Pateira de Fermentelos, Águeda, as a source of phytosterols, namely stigmasterol, by Soxhlet and supercritical fluid extraction. Supercritical extractions were used in this thesis as an alternative to conventional techniques that use organic solvents, allowing the assessment of both extractions in terms of concentration, yield and selectivity for stigmasterol. In both cases chemical evaluation was carried out using different techniques: GCMS, total phenol content and antioxidant activity. With this intent, an experimental work plan was established. First, the biomass was harvested and divided in its different morphological parts, roots, stalks, leaves and flowers. Secondly, soxhlet extractions with dichloromethane were performed and the extracts analyzed by GC-MS. This step revealed a strong stigmasterol concentration in stalks and leaves (15.0% and 13.5%; mg/100mgextract) and a total yield value of 1.12, 2.65, 3.30 and 4.45 wt.% respectively. Thirdly, solid liquid extractions were performed and total phenolic and antioxidant activity were assessed, revealing that leaves possessed higher phenolic content and antioxidant activity than all other morphological parts. Finally, supercritical fluid extractions (SFE) were performed. These were divided in two stages. In the preliminary stage, a mixture of all parts where submitted to extraction revealing a lower overall extraction yield but higher stigmasterol concentration (31% mg/100mgextract). The second phase of SFE was performed in order to obtain the overall extraction curves (OEC). These were performed with a biomass mixture that revealed a higher stigmasterol content, namely stalks and leaves. These extractions demonstrated that temperature had little effect on the total yield, that the optimal time of extraction was of one hour and the maximum stigmasterol concentration was achieved after two hours of extraction. Regarding the modeling of the extraction curves, internal diffusion revealed to be the dominant mass transfer mechanism. In sum, these results show that supercritical extraction of E. crassipes biomass can become a promising extraction technology, generating rich stigmasterol extracts, opening a possible window for its commercial implementation. |
publishDate |
2014 |
dc.date.none.fl_str_mv |
2014-07-28T00:00:00Z 2014-07-28 2016-07-28T14:00:00Z 2018-07-20T14:00:49Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/14299 TID:201592142 |
url |
http://hdl.handle.net/10773/14299 |
identifier_str_mv |
TID:201592142 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade de Aveiro |
publisher.none.fl_str_mv |
Universidade de Aveiro |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799137549589938176 |