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Authors
Abstract(s)
Os óleos e gorduras são os principais ingredientes de diversos produtos
alimentares, no entanto o consumo em excesso desses compostos está diretamente
associado a doenças como obesidade, diabetes e doenças cardiovasculares. Tendo em
consideração este aspecto, a procura pelo desenvolvimento de alimentos com baixo teor
de gordura e que mantenham uma qualidade sensorial similar à dos produtos tradicionais
representa um desafio para a indústria alimentar. Um dos métodos explorados pela
tecnologia de alimentos para a substituição de gorduras compreende a preparação de
emulsões. Entre outras, cabe destacar, as emulsões Pickering, sistemas inovadores
estabilizados por partículas coloidais, caracterizadas por possuíram elevada resistência a
fenômenos de coalescência e amadurecimento de Ostwald em comparação com as
emulsões tradicionais baseadas em surfactantes. Além disso, oferecem a oportunidade de
incorporar compostos bioativos por meio da utilização das partículas como encapsulantes.
Assim, o presente trabalho teve como principal objetivo desenvolver emulsões Pickering
estabilizadas com partículas contendo curcumina obtidas pelo método de dispersão
sólida. Com essa estratégia pretendeu-se obter uma emulsão promissora para aplicação
na indústria alimentar como substituto de maionese com redução de gordura.
Inicialmente, com base em testes preliminares foram selecionadas quatro formulações de
nanopartículas que manifestaram potencial em atuar como partículas Pickering,
nomeadas de KC1, KC2, PVA e PVP, quais foram produzidas pela técnica de dispersão
sólida utilizando os polímeros k-carragenina, álcool polivinílico ou polivinilpirrolidona,
e caracterizadas através da análise de cor, molhabilidade e tamanho de partícula. Deste
modo, o trabalho prosseguiu com a produção e otimização das emulsões Pickering
testando-se diferentes razões óleo/água e concentração de partículas, com o fim de obter
formulações estáveis. As emulsões, produzidas com azeite neutro para minimizar a
influência das propriedades da fase óleo nos sistemas, foram avaliadas quanto à
morfologia, tipo de emulsão e analisadas visualmente. Por conseguinte, foram atingidos
três sistemas estáveis, sendo esses: KC1 φ 0,4 (4,7%), KC2 φ 0,4 (4,7%) e KC2 φ 0,6
(4,0%). Conforme os resultados obtidos, as emulsões otimizadas foram produzidas
substituindo o azeite neutro por um azeite virgem para adequação à aplicação alimentar.
A partir de testes de estabilidade ao longo do tempo e análises de cor e pH, as emulsões
com azeite virgem demonstraram ser tão estáveis e atrativas à aplicação quanto as
produzidas com azeite neutro. Por fim, as emulsões otimizadas com azeite virgem foram sujeitas a análises de estabilidade oxidativa, avaliação das propriedades de textura e
caracterização nutricional, utilizando como matrizes alimentares de comparação dois
tipos de maioneses comerciais (tradicional e light). As três emulsões apresentaram
estabilidade oxidativa significativamente superior às das maioneses comerciais,
representando um tempo de prateleira superior. A emulsão KC1 φ 0,4 (4,7%) apresentou
textura e valor nutricional próximos da maionese light comercial, indicando assim, ser
uma emulsão promissora para aplicação como produto natural substituto de maionese
com baixo teor de gordura, além de proporcionar benefícios para a saúde do consumidor
derivado das propriedades da curcumina e do azeite virgem.
Oils and fats are the main ingredients of several food products; however, the excessive consumption of these compounds is directly associated with diseases such as obesity, diabetes and cardiovascular diseases. In this context, the demand for developing foods with fat reduction maintaining the sensorial quality similar to that of traditional products, represents a challenge for the food industry. One of the methods explored by food technology for fats replacement is based on emulsion approaches. Among others, it is to highlight that Pickering emulsions consist on innovative systems stabilized through colloidal particles, characterized by holding high resistance to coalescence and Ostwald ripening phenomena in comparison with conventional surfactant based emulsions. Moreover, they provide the opportunity to incorporate bioactive compounds through the encapsulation in the particles. In this context, the main objective of the present work comprise the development of Pickering emulsions stabilized by particles incorporating curcumin produced by the solid dispersion method. With this strategy it was intended to obtain a promising emulsion to be used in the food industry as a substitute of low fat mayonnaise. Initially, based on preliminary tests, four nanoparticle formulations were selected, which showed the potential to act as Pickering stabilizers, designated as KC1, KC2, PVA and PVP, which were produced by the solid dispersion technique with the polymers k-carrageenan, polyvinyl alcohol or polyvinylpyrrolidone, and characterized in terms of color, wettability and particle size. Afterwards, the work proceeded with the production and optimization of the Pickering emulsions by testing different oil/water ratios and particle concentrations, in order to obtain stable formulations. The emulsions, produced with neutral oil to minimize the influence of the oil properties in the systems, were evaluated by means of morphology, type of emulsion and visually inspected. Three stable systems were obtained, corresponding to the formulations: KC1 φ 0.4 (4.7%), KC2 φ 0.4 (4.7%) and KC2 φ 0.6 (4.0%). According to the obtained results, the optimized emulsions were produced by replacing the neutral olive oil with virgin olive oil to be directed to food applications. Based on stability tests over time and color and pH analysis, emulsions prepared with virgin olive oil demonstrated to be as stable and attractive as those prepared with neutral olive oil. Finally, the emulsions optimized with virgin olive oil in view of food applications, were evaluated through oxidative stability, texture and nutritional properties, using two types of commercial mayonnaise (traditional and light) for comparison purposes. The three emulsions showed significantly higher oxidative stability in comparison with commercial mayonnaise, implying their longer shelf life. The KC1 φ 0.4 (4.7%) emulsion showed textural and nutritional results similar to that one of the commercial light mayonnaise, thus indicating its potential applicability as a natural substitute of low fat content, besides providing health benefits to the consumer derived from the curcumin and virgin olive oil properties.
Oils and fats are the main ingredients of several food products; however, the excessive consumption of these compounds is directly associated with diseases such as obesity, diabetes and cardiovascular diseases. In this context, the demand for developing foods with fat reduction maintaining the sensorial quality similar to that of traditional products, represents a challenge for the food industry. One of the methods explored by food technology for fats replacement is based on emulsion approaches. Among others, it is to highlight that Pickering emulsions consist on innovative systems stabilized through colloidal particles, characterized by holding high resistance to coalescence and Ostwald ripening phenomena in comparison with conventional surfactant based emulsions. Moreover, they provide the opportunity to incorporate bioactive compounds through the encapsulation in the particles. In this context, the main objective of the present work comprise the development of Pickering emulsions stabilized by particles incorporating curcumin produced by the solid dispersion method. With this strategy it was intended to obtain a promising emulsion to be used in the food industry as a substitute of low fat mayonnaise. Initially, based on preliminary tests, four nanoparticle formulations were selected, which showed the potential to act as Pickering stabilizers, designated as KC1, KC2, PVA and PVP, which were produced by the solid dispersion technique with the polymers k-carrageenan, polyvinyl alcohol or polyvinylpyrrolidone, and characterized in terms of color, wettability and particle size. Afterwards, the work proceeded with the production and optimization of the Pickering emulsions by testing different oil/water ratios and particle concentrations, in order to obtain stable formulations. The emulsions, produced with neutral oil to minimize the influence of the oil properties in the systems, were evaluated by means of morphology, type of emulsion and visually inspected. Three stable systems were obtained, corresponding to the formulations: KC1 φ 0.4 (4.7%), KC2 φ 0.4 (4.7%) and KC2 φ 0.6 (4.0%). According to the obtained results, the optimized emulsions were produced by replacing the neutral olive oil with virgin olive oil to be directed to food applications. Based on stability tests over time and color and pH analysis, emulsions prepared with virgin olive oil demonstrated to be as stable and attractive as those prepared with neutral olive oil. Finally, the emulsions optimized with virgin olive oil in view of food applications, were evaluated through oxidative stability, texture and nutritional properties, using two types of commercial mayonnaise (traditional and light) for comparison purposes. The three emulsions showed significantly higher oxidative stability in comparison with commercial mayonnaise, implying their longer shelf life. The KC1 φ 0.4 (4.7%) emulsion showed textural and nutritional results similar to that one of the commercial light mayonnaise, thus indicating its potential applicability as a natural substitute of low fat content, besides providing health benefits to the consumer derived from the curcumin and virgin olive oil properties.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Emulsões Pickering Dispersão sólida Curcumina Aplicações alimentares