Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/5735
Título: Caracterização química e avaliação da atividade antioxidante da farinha de dreche
Autor: Costa, Maria Alexandra da Purificação Rodrigues Neto
Orientador: Sousa, Isabel Maria Nunes de
Alves, Vitor Manuel Delgado
Palavras-chave: brewers spent grain
antioxidant activity
chemical characterization
DHPP method
FRAP method
Data de Defesa: 2013
Editora: ISA/UTL
Citação: Costa, M.A.P.R.N. - Caracterização química e avaliação da atividade antioxidante da farinha de dreche. Lisboa: ISA, 2013
Resumo: Resulting from the filtration of wort, BSG is, among others, a by-product of the brewing industry. With the purpose of transforming this by-product in raw material to use in the baking industry, some of the bioactive components have been quantified, namely minerals, polysaccharides, phenolic components and antioxidant capacity of its components (AOA). The AOA was measured directly on BSG flour by DPPH method and ranged from 0.034 to 0.011 TEAC (M Trolox/100 g flour). When using the FRAP method, values varied between 0,066 and 0,031 TEAC (M Trolox/100g flour). These values were dependent on the concentration of flour and extract in the mixture and are lower than the ones obtained in tomato repiso, oregano and gorse. As for the mineral fraction, 100 gr of flour contains 260 mg of calcium, 255 mg of phosphorus, 186 mg of magnesium, 9 mg of sodium, 7 mg of iron and 4 mg of zinc, these levels are higher when compared to the ones for wheat and rye flours. Using spectrophotometry at 280 nm in concentrated aqueous solution, it was observed that the total phenolic content was of 18,63 mg EAG/g extract and by using the aqueous extraction process it was obtained a yield of 7% lyophilized extract, 80% insoluble solids and 2% polysaccharides. From all the results obtained it can be concluded that BSG flour has some antioxidant activity and high contents of minerals leading to the conclusion that can be incorporated in bakery products as a source to increase bioactive components.
Descrição: Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
URI: http://hdl.handle.net/10400.5/5735
Aparece nas colecções:BISA - Dissertações de Mestrado / Master Thesis

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