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Advisor(s)
Abstract(s)
A indústria de alimentos depende do uso de emulsões e agentes emulsionantes, para
a produção de cremes, molhos para salada, maionese e sopas. As emulsões óleo em água
são formadas a partir da homogeneização destas duas fases na presença de um ou mais
emulsionantes, tais como proteínas, que possuem caráter anfifílico. Grande parte dos
emulsionantes utilizados pela indústria alimentar são de origem sintética, fato que tem
gerado uma busca pela utilização de ingredientes naturais e sustentáveis, além de
incentivar o estudo das propriedades reológicas das microalgas. As microalgas são fonte
de biomoléculas, como proteínas, que tem apresentado excelentes capacidades
emulsionantes. Entre estas microalgas, podemos destacar a Arthrospira platensis,
Chlorella vulgaris e Nannochloropsis oceanica, que podem conter de 18 a 77% de
proteína. A extração desse composto a partir das microalgas tem sido feito por meio de
diversas técnicas de ruptura celular, como por exemplo a tecnologia de ultrassons. As
ondas ultrassónicas facilitam a rutura e diminuição das partículas das células microalgais,
além de melhorar a eficiência dos processos para a extração de proteínas. Entre os
sistemas atualmente disponíveis, os ultrassons tipo sonda e banho são os mais utilizados.
Deste modo, o objetivo deste trabalho consistiu na extração de proteínas a partir da
biomassa desidratada das microalgas A. platensis, C. vulgaris e N. oceanica, por meio de
tratamento ultrassónico usando equipamento tipo sonda e banho, concomitante com a
agitação em meio alcalino, caracterização do extrato proteico (rendimento global e
proteico, valor nutricional e energético, FTIR), avaliação das suas propriedades
funcionais (solubilidade, CAágua, CAóleo, CFespuma, Eespuma) e sua utilização como
emulsionante. A A. platensis aprensentou os melhores resultados em termos de
rendimento global e proteico para ambos os métodos de extração. Contudo, o extrato
obtido em banho de ultrassons apresentou maior concentração de ficocianina (116,14
μg/mL), que é um pigmento fotossintético presente num conteúdo de 15 a 20% na
composição proteica desta microalga, além de ter apresentado um menor teor de lípidos
(0,44 g/100g ms). Devido aos melhores resultados, o extrato proteico obtido em banho de
ultrassons foi utilizado para preparar emulsões, procedimento para o qual foi aplicado um
PFF (24-1) para a avaliação do efeito de 4 variáveis do processo (razão óleo/água,
concentração de extrato proteico, pH e tempo de armazenamento) na estabilidade das emulsões formadas (potencial zeta, tamanho de partícula, creaming index, microscopia
óptica). Todas as emulsões se mostraram estáveis por até 14 dias.
The food industry depends on the use of emulsions and emulsifying agents for the production of creams, salad dressings, mayonnaise, and soups. Oil-in-water emulsions are formed by the homogenization of these two phases in the presence of one or more emulsifiers, e.g. proteins, compounds that have an amphiphilic character. Most of the emulsifiers used by the food industry are synthetic, motivating the searches for more natural and sustainable ingredients, apart from incentivising the study of the rheological properties of microalgae. Microalgae are a source of biomolecules, such as proteins, which have shown excellent emulsifying capabilities. Among microalgae, we can highlight Arthrospira platensis, Chlorella vulgaris, and Nannochloropsis oceanica, which may contain 18 to 77% protein. The extraction of this compound from the microalgae has been done through several techniques of cell disruption, such as ultrasound technology. Ultrasonic waves facilitate the breakdown and reduction of microalgal cell particles helping to improve the efficiency of the processes for protein extraction. Ultrasound probe and bath are the most widely used techniques among the ones currently available. Therefore the objective of this work is the extraction of proteins from the dehydrated biomass of the microalgae A. platensis, C. vulgaris and N. oceanica, using ultrasonic treatment with a probe and trough a bath equipment, combined with stirring in alkaline medium, characterization of the protein extract (total and protein yield, nutritional and energetic value, FTIR), evaluation of their functional properties (solubility, water and oil absorption capacity, foaming capacity, foam stability) and test of their use as an emulsifier. A. platensis showed the best results in terms of total and protein yield for both extraction methods. However, the extract obtained by ultrasound bath showed the higher concentration of phycocyanin (116,14 μg/mL), which is a photosynthetic pigment present at a content of 15 to 20% in this microalgae protein composition, also having the lower lipid content (0,44 g/100g ms). Due to the observed best results, the protein extract obtained by ultrasound bath was used to prepare emulsions, for which a procedure PFF (24-1) was applied to evaluate the effect of 4 process variables (oil/water ratio, concentration of protein extract, pH, and storage time) on the stability of the formed emulsions (zeta potential, particle size, creaming index, optical microscopy). All the prepared emulsions remain stable for up to 14 days.
The food industry depends on the use of emulsions and emulsifying agents for the production of creams, salad dressings, mayonnaise, and soups. Oil-in-water emulsions are formed by the homogenization of these two phases in the presence of one or more emulsifiers, e.g. proteins, compounds that have an amphiphilic character. Most of the emulsifiers used by the food industry are synthetic, motivating the searches for more natural and sustainable ingredients, apart from incentivising the study of the rheological properties of microalgae. Microalgae are a source of biomolecules, such as proteins, which have shown excellent emulsifying capabilities. Among microalgae, we can highlight Arthrospira platensis, Chlorella vulgaris, and Nannochloropsis oceanica, which may contain 18 to 77% protein. The extraction of this compound from the microalgae has been done through several techniques of cell disruption, such as ultrasound technology. Ultrasonic waves facilitate the breakdown and reduction of microalgal cell particles helping to improve the efficiency of the processes for protein extraction. Ultrasound probe and bath are the most widely used techniques among the ones currently available. Therefore the objective of this work is the extraction of proteins from the dehydrated biomass of the microalgae A. platensis, C. vulgaris and N. oceanica, using ultrasonic treatment with a probe and trough a bath equipment, combined with stirring in alkaline medium, characterization of the protein extract (total and protein yield, nutritional and energetic value, FTIR), evaluation of their functional properties (solubility, water and oil absorption capacity, foaming capacity, foam stability) and test of their use as an emulsifier. A. platensis showed the best results in terms of total and protein yield for both extraction methods. However, the extract obtained by ultrasound bath showed the higher concentration of phycocyanin (116,14 μg/mL), which is a photosynthetic pigment present at a content of 15 to 20% in this microalgae protein composition, also having the lower lipid content (0,44 g/100g ms). Due to the observed best results, the protein extract obtained by ultrasound bath was used to prepare emulsions, for which a procedure PFF (24-1) was applied to evaluate the effect of 4 process variables (oil/water ratio, concentration of protein extract, pH, and storage time) on the stability of the formed emulsions (zeta potential, particle size, creaming index, optical microscopy). All the prepared emulsions remain stable for up to 14 days.
Description
Mestrado de dupla diplomação com a Universidade Tecnológica Federal do Paraná
Keywords
Microalgas Arthrospira platensis Chlorella vulgaris Nannochloropsis oceanica