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Advisor(s)
Abstract(s)
As dietas de base vegetal apresentam-se como uma alternativa viável para garantir um futuro sustentável, uma vez que utilizam muito menos recursos naturais e são menos onerosas para o meio ambiente, em comparação com as dietas ricas em produtos de base animal. Este projeto visou o desenvolvimento de uma alternativa vegetal ao ovo líquido. O produto teve por base uma bebida de soja de modo de produção biológica sem açúcares, à qual foram adicionados ingredientes específicos para que a formulação final respeitasse ao máximo o perfil organolético original, a componente nutricional mais relevante, assim como o comportamento funcional dos ovos quando mexidos em frigideira. A metilcelulose e a k-carragenina foram utilizadas como agentes gelificantes, o amido foi utilizado como agente texturizante, e o nigari permitiu a coagulação das proteínas de soja desnaturadas pelo calor. A matriz continha ainda óleo de girassol para aproximar a componente lipídica do análogo à encontrada no ovo de galinha, e lecitina de soja para permitir a emulsão. A mistura para o tempero continha sal negro dos Himalaias, levedura nutricional, cebola em pó, alho em pó e pimentão doce. Foi avaliado o efeito do processamento HPP (550 MPa por 3 min a aproximadamente 20 ºC) na qualidade microbiológica e prazo de validade do análogo quando armazenado a 4º C ao longo de 45 e 15 dias, em duas experiências distintas, respetivamente. Atendendo à contagem de mesófilos totais, a qual alcançou valores > 7.0 Log (ufc/mL) aos 30 dias de armazenamento, o tempo de prateleira do análogo ao ovo líquido na primeira experiência foi estimado entre os 15 e os 30 dias, no entanto na segunda experiência este foi reduzido a aproximadamente 7 a 15 dias. A análise centesimal permitiu detalhar o perfil nutricional do análogo, apresentando por 100 g de produto um valor energético de 85 kcal, teor de gordura total de 6,2 %, sendo que contém 1,0 % de ácidos gordos saturados, teor de hidratos de carbono totais 3,5 %, sendo que desses 0,8 % correspondem a açúcares simples e o teor em proteína de 4,0 %. Testes reológicos revelaram que a viscosidade do análogo vegetal ao ovo líquido aumentou entre os 7 e os 15 dias de armazenamento, até a um máximo de cerca de 150 e 200% (viscosidade complexa e viscosidade instantânea, respetivamente). O análogo desenvolvido apresenta um perfil organolético semelhante ao ovo de galinha, no entanto barreiras como o baixo teor proteico e a reduzida estabilidade microbiológicas terão de ser ultrapassadas.
Vegetarian diets are a viable alternative to ensure a sustainable future, as they use fewer natural resources and have a lower environmental impact than those based on animal products. The aim of this project was to develop a vegetable alternative to liquid egg based on a sugar-free organic soy drink. Specific ingredients were added so that the final formulation respected the original as much as possible the most relevant nutritional component, the organoleptic profile. The functional behaviour of eggs scrambled in a skillet was also mimicked. Methylcellulose and k-carrageenan were used as gelling agents, starch as a texturizing agent, nigari for the coagulation of heat-denatured soy proteins and soy lecithin to allow for emulsion. Also, by adding sunflower oil to the matrix, a lipid component similar to that found in chicken eggs was achieved. The seasoning mix contained Himalayan black salt, nutritional yeast, onion powder, garlic powder and sweet pepper, elevating the flavour profile of the product. In order to test the effect of HPP (High-pressure processing) processing by submitting the analogue to 550 MPa for 3 min at approximately 20 ºC. The microbiological quality and shelf life of the analogue when stored at 4ºC for 45 and 15 days was evaluated in two different experiments, respectively. Considering the total mesophilic count, which reached values > 7.0 Log (cfu/mL) at 30 days of storage, the shelf life of the liquid egg analogue in the first experiment was estimated between 15 and 30 days, however in the second experiment this was reduced to approximately 7 to 15 days. The nutritional profile of the analogue was detailed by proximate analysis, with a final estimated energy value of 85 kcal per 100 g of product, total fat content of 6.2%, containing 1.0% of saturated fatty acids, hydrates content of total carbon 3.5%, of which 0.8% correspond to simple sugars and a protein content of 4.0%. Rheological tests revealed that the viscosity of the vegetable analogue to the liquid egg increased between 7 and 15 days of storage, up to a maximum of about 150% of complex viscosity and 200% of instantaneous viscosity. In summary, the developed analogue has an organoleptic profile resembling that of chicken eggs, however barriers such as low protein content and reduced microbiological stability will have to be overcome to achieve a capable vegetarian alternative.
Vegetarian diets are a viable alternative to ensure a sustainable future, as they use fewer natural resources and have a lower environmental impact than those based on animal products. The aim of this project was to develop a vegetable alternative to liquid egg based on a sugar-free organic soy drink. Specific ingredients were added so that the final formulation respected the original as much as possible the most relevant nutritional component, the organoleptic profile. The functional behaviour of eggs scrambled in a skillet was also mimicked. Methylcellulose and k-carrageenan were used as gelling agents, starch as a texturizing agent, nigari for the coagulation of heat-denatured soy proteins and soy lecithin to allow for emulsion. Also, by adding sunflower oil to the matrix, a lipid component similar to that found in chicken eggs was achieved. The seasoning mix contained Himalayan black salt, nutritional yeast, onion powder, garlic powder and sweet pepper, elevating the flavour profile of the product. In order to test the effect of HPP (High-pressure processing) processing by submitting the analogue to 550 MPa for 3 min at approximately 20 ºC. The microbiological quality and shelf life of the analogue when stored at 4ºC for 45 and 15 days was evaluated in two different experiments, respectively. Considering the total mesophilic count, which reached values > 7.0 Log (cfu/mL) at 30 days of storage, the shelf life of the liquid egg analogue in the first experiment was estimated between 15 and 30 days, however in the second experiment this was reduced to approximately 7 to 15 days. The nutritional profile of the analogue was detailed by proximate analysis, with a final estimated energy value of 85 kcal per 100 g of product, total fat content of 6.2%, containing 1.0% of saturated fatty acids, hydrates content of total carbon 3.5%, of which 0.8% correspond to simple sugars and a protein content of 4.0%. Rheological tests revealed that the viscosity of the vegetable analogue to the liquid egg increased between 7 and 15 days of storage, up to a maximum of about 150% of complex viscosity and 200% of instantaneous viscosity. In summary, the developed analogue has an organoleptic profile resembling that of chicken eggs, however barriers such as low protein content and reduced microbiological stability will have to be overcome to achieve a capable vegetarian alternative.
Description
Keywords
Análogo vegetal ao ovo Soja Agentes gelificantes Coagulação Processamento HPP Vegetable analogue to egg Soybean Gelling agents Coagulation HPP Processing