Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/3876
Título: Microbiological and lipid profiles of broa: contributions for the characterization of a traditional portuguese bread
Outros títulos: Perfil microbiologico e lipidico da broa: contribuições para a caracterização de um pão tradicional português
Autor: Rocha, João Miguel Ferreira da
Orientador: Malcata, Francisco Xavier
Beirão da Costa, Maria Luísa
Palavras-chave: broa
fatty acids
glycerides and sterols
neural lipids
sourdough
microflora
Data de Defesa: 2011
Editora: ISA/UTL
Citação: Rocha, João Miguel Ferreira - Microbiological and lipid profiles of broa: contributions for the characterization of a traditional portuguese bread. Lisboa, ISA, 2011
Resumo: Scientific knowledge of artisanal broa contributes to a better quality and market expansion thereof. Towards this purpose, samples from fourteen artisanal producers were assayed for comprehensive microbial and lipid identification and quantification. Fermentation played a major role upon the prevailing microflora: viable numbers of yeasts, lactobacilli, streptococci, lactococci, enterococci and leuconostocs increased, whereas those of molds, Enterobacteriaceae, Pseudomonadaceae, staphylococci and micrococci decreased. After fermentation, yeasts and lactic‐acid bacteria dominated. Neutral‐lipids were quantified by normal phase‐high performance liquid chromatographyevaporative‐ light scattering detection and electrospray ionization‐tandem mass‐spectrometry, after employing two independent extraction procedures – yielding non‐starch and starch lipids, as well as free, bound and starch lipids. Solid‐phase extraction separated neutral‐lipids prior to derivatization of sterol‐esters, triacylglycerol, free‐fatty acids, sterols with diacylglycerols and monoacylglycerols, permitted fatty‐acids separation by gas‐liquid chromatography. Breadmaking affected lipid extractability, and neutral‐lipid and fatty‐acid profiles. Triacylglycerols decreased during dough‐mixing and fermentation – so those of diacylglycerols and monoacylglycerols increased, whereas sterol‐esters remained constant; the effect of baking was less pronounced. Triacylglycerols dominated, but sterol‐esters, diacylglycerols and free‐fatty acid amounts were considerable. Palmitic, oleic and linoleic acids were dominant. The nutritional value of broa was apparent, owing to poly‐ and monoene dominance
Descrição: Doutoramento em Engenharia Alimentar - Instituto Superior de Agronomia
URI: http://hdl.handle.net/10400.5/3876
Aparece nas colecções:BISA - Teses de Doutoramento / Doctoral Thesis

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