Obtenção de compostos fenólicos em pó por liofilização a partir da torta residual de pequi
Carregando...
Data
2020-02-28
Autores
Nunes, Natalie Stephanie Sawada
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Cerrado, segundo maior bioma brasileiro, possui uma rica flora e fauna dentre as savanas do mundo. O pequi (Caryocar brasiliense Camb.) é um fruto nativo desse bioma e apresenta muitos compostos bioativos como carotenoides, vitaminas A e E e compostos fenólicos que possuem ações anticarcinogênicas, antimicrobianas e antioxidantes. Esses compostos, no entanto, são sensíveis a exposição à luz e oxigênio. Para amenizar essa degradação podem ser utilizados métodos de encapsulação. A extração do óleo da polpa de pequi, por prensagem a frio, gera uma torta residual rica em compostos bioativos. Portanto, o objetivo do presente trabalho foi a encapsulação dos compostos fenólicos presentes na torta residual por meio da liofilização utilizando diferentes agentes encapsulantes (amido de mandioca modificado, goma arábica, maltodextrina e ovoalbumina). Para tanto foi obtido um extrato aquoso (1:6 m/v) da torta residual utilizando extração ultrassônica com os seguintes parâmetros: 240 W de potência, 50% de pulso e 10 minutos. Os materiais encapsulantes corresponderam a 20% do extrato. Inicialmente, o extrato foi misturado aos agentes encapsulantes puros com o intuito de verificar quais os melhores encapsulantes. Numa segunda etapa, foram utilizadas misturas de amido de mandioca modificado (AM) e maltodextrina (MD) para misturas nas proporções de 50% de AM e 50% de MD; 75% AM e 25% MD e 25% AM e 75% MD. Todas as amostras foram liofilizadas a -50 °C por 48 horas, originando pós de cor amarelada, os quais foram avaliados com relação às características físico-químicas. Após secagem, os pós apresentaram 3 a 4% de umidade, tanto nos pós com agentes encapsulantes puros como nas misturas de AM e MD. Nos processos utilizando agentes encapsulantes puros, o rendimento foi maior para o amido de mandioca modificado (73,1%) e os valores de retenção dos compostos fenólicos variaram entre 66-50%, sendo o maior para a goma arábica e o menor para a ovoalbumina. Os rendimentos obtidos com as misturas de AM e MD apresentaram uma média de 73,6% e a mistura de 75% AM e 25% MD alcançou retenção de compostos fenólicos de 90%, destacando-se entre as demais. Essa mistura demonstrou baixa higroscopicidade (10%), indicando uma boa estabilidade do material. A mistura 75% AM e 25% MD e o extrato liofilizado foram submetidos a testes de estabilidade a uma temperatura de 25 ºC e exposição à luz (800 lux) durante 28 dias. Durante os 7 primeiros dias de armazenamento ambas amostras tiveram perdas significativas de compostos fenólicos, entretanto as amostras encapsuladas apresentaram perdas menores. O extrato puro apresentou grande variação de cor durante o armazenamento (∆E = 12,1), como consequência da possível perda de carotenoides. O AM e MD atuaram como bons agentes carreadores.
The Cerrado, the second largest Brazilian biome, has a rich flora and fauna among the world’s savannas. Pequi (Caryocar Brasiliense Camb.) is a native fruit of this biome and has several bioactive compounds such as carotenoids, vitamins A and E and phenolic compounds that perform anticarcinogenic, antimicrobial and antioxidants actions. These compounds, however, are sensitive to light and oxygen exposure. To mitigate this degradation, encapsulation methods can be used. The oil extraction from pequi pulp, by cold pressing, generates a residual cake rich in bioactive compounds. Therefore, the objective of the present work was the encapsulation of the phenolic compounds present in the residual cake by freeze-drying using different encapsulating agents (modified cassava starch, Arabic gum, maltodextrin and ovoalbumin). For this, an aqueous extract (1:6 m/v) of the residual cake was obtained using ultrasonic extraction with the following parameters: 240 W of power, 50% of pulse and 10 minutes. The encapsulating materials corresponded to 20% of the extract. Initially, the extract was mixed with pure encapsulating in order to verify which are the best encapsulating. In second stage, modified cassava starch (AM) and maltodextrin (MD) were used for mixtures in the proportions of 50% AM and 50% MD; 75% AM and 25 MD and 25% AM and 75% MD. All samples were freezing drying at -50°C for 48 hours, resulting in yellowish powders, which were evaluated for physicochemical characteristics. After drying, the powders showed 3,4% moisture, both in powders with pure encapsulating agents and in mixture of AM and MD. In the processes using pure encapsulating agents, the yield was higher for modified cassava starch (73.1%) and the retention values of phenolic compounds varied between 66-50%, the highest for gum Arabic and the lowest for ovalbumin. The yields obtained with AM and MD mixtures showed an average of 73.6% and the mixture of 75% AM and 25% MD achieved retention of 90% phenolic compounds, standing out among the others. This mixture showed low hygroscopicity (10%), indicating good material stability. The 75% AM and 25% MD mixture and the freezing drying extract were subjected to stability tests at 25 ºC and light exposure (800 lux) for 28 days. During the first 7 days of storage both samples had significant losses of phenolic compounds, however the encapsulated samples showed smaller losses. The pure extract showed great color variation during storage (∆E = 12,1), as a consequence of the possible loss of carotenoids. AM and MD acted as good carrier agents.
The Cerrado, the second largest Brazilian biome, has a rich flora and fauna among the world’s savannas. Pequi (Caryocar Brasiliense Camb.) is a native fruit of this biome and has several bioactive compounds such as carotenoids, vitamins A and E and phenolic compounds that perform anticarcinogenic, antimicrobial and antioxidants actions. These compounds, however, are sensitive to light and oxygen exposure. To mitigate this degradation, encapsulation methods can be used. The oil extraction from pequi pulp, by cold pressing, generates a residual cake rich in bioactive compounds. Therefore, the objective of the present work was the encapsulation of the phenolic compounds present in the residual cake by freeze-drying using different encapsulating agents (modified cassava starch, Arabic gum, maltodextrin and ovoalbumin). For this, an aqueous extract (1:6 m/v) of the residual cake was obtained using ultrasonic extraction with the following parameters: 240 W of power, 50% of pulse and 10 minutes. The encapsulating materials corresponded to 20% of the extract. Initially, the extract was mixed with pure encapsulating in order to verify which are the best encapsulating. In second stage, modified cassava starch (AM) and maltodextrin (MD) were used for mixtures in the proportions of 50% AM and 50% MD; 75% AM and 25 MD and 25% AM and 75% MD. All samples were freezing drying at -50°C for 48 hours, resulting in yellowish powders, which were evaluated for physicochemical characteristics. After drying, the powders showed 3,4% moisture, both in powders with pure encapsulating agents and in mixture of AM and MD. In the processes using pure encapsulating agents, the yield was higher for modified cassava starch (73.1%) and the retention values of phenolic compounds varied between 66-50%, the highest for gum Arabic and the lowest for ovalbumin. The yields obtained with AM and MD mixtures showed an average of 73.6% and the mixture of 75% AM and 25% MD achieved retention of 90% phenolic compounds, standing out among the others. This mixture showed low hygroscopicity (10%), indicating good material stability. The 75% AM and 25% MD mixture and the freezing drying extract were subjected to stability tests at 25 ºC and light exposure (800 lux) for 28 days. During the first 7 days of storage both samples had significant losses of phenolic compounds, however the encapsulated samples showed smaller losses. The pure extract showed great color variation during storage (∆E = 12,1), as a consequence of the possible loss of carotenoids. AM and MD acted as good carrier agents.
Descrição
Palavras-chave
Liofilização, Ultrassom, Bioativos, Fenólicos, Freeze drying, Ultrasound, Bioactive, Phenolic compounds