Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/4063
Título: Estabelecimento de uma metodologia de determinação do tempo de vida útil de alguns óleos vegetais
Autor: Henriques, Lúcia Rodrigues
Orientador: Arês, Paula Isabel Barradas
Cardoso, Ana Isabel Tonim
Martins, Maria Luísa Louro
Palavras-chave: vegetable oils
shelf-life
oxidative stability
peroxide values
acidity
absorbances
Data de Defesa: 2011
Editora: ISA/UTL
Citação: Henriques, Lúcia Rodrigues - Estabelecimento de uma metodologia de determinação do tempo de vida útil de alguns óleos vegetais. Lisboa: ISA, 2011
Resumo: The main goal of the present work was the establishment of a methodology to predict the shelf-life of different vegetable oils. The oxidative evolution of three vegetable oils (sunflower oil, soybean oil and peanut oil) at room temperature was evaluated during 18 months. A fast degradation process of two oils (sunflower oil and sunflower oilspray ) was simulated by heating at temperatures of 42, 50 and 55 °C, in an oven, and by performing Rancimat tests as well. The oxidative evolution was followed by measuring the peroxide value, acidity and absorbances. The organoleptic characteristics (flavor and aroma) were also evaluated in several samples. It was found that the oxidative stability of each oil can be described by models that allows a shelf-life prediction, from the determination of the peroxide value, absorbances and acidity values, organoleptic evaluation and stability times obtained in Rancimat tests. It was concluded that the experiments carried out at room temperature are more suitable for predicting the shelf-life of oils, since, in trials at higher temperature, the faster degradation of oils influence the oxidation mechanisms and consequently the results of this prediction.
Descrição: Mestrado em Engenharia Alimentar - Qualidade e Segurança Alimentar - Instituto Superior de Agronomia
URI: http://hdl.handle.net/10400.5/4063
Aparece nas colecções:BISA - Dissertações de Mestrado / Master Thesis

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