Isolado proteico de girassol obtenção e propriedades / Isolated protein sunflower production and properties

AUTOR(ES)
DATA DE PUBLICAÇÃO

1984

RESUMO

The physical and chemical characteristics of eight varieties of sunflower seeds of commercia1 importance in Brazil were studied.The IAC-Anhandy, a new cultivar devéloped at the Instituto Agronômico in Campinas, SP, presented the highest levels of oil and ] ernel. The protein content of the several varieties of sunflower seeds ranged from 15.38% to 25.28%. In relation to the FAO standard for protein, 1973,sun-f10wer proteins exhibited lysine deficiency (3.5g/100g of protein) and a high content of sU1fur-contain!ng amino acids (5.2g/100g of protein). AlI eight varieties had a high leveI of unsaturated fatty acids (86.3-91.1%), main1y lin01eic (37.4-69.0%) and oleic acids (19.9-53.7%). The chlrogenic acid content in the defatted sunf10wer f10ur varied b~ 3.60% and 5.51%, ín the dry basis.The optimum conditions for protein extraction were determinedusing defatted f10ur of the IAC-Anhandy variety.ThelÜghestyield,of 94t, was. obtained using the following conditions: flour: water ratio, 1:10 .(w/v) i stirring time, 30 mini temperature, 30QCi pH, 10.0. n order to avoid the deve10pment of.an undesirab1e green color, due to chlorogenic acid oxidation, the protein extraction was pe! formed in the presence of different concentrations of sodiurn tetrabora te, ascorbate or metabisulfite. These reagents showed a inhibitory effect on the green color formation. Thebest efficiency in color inhibition and the highest yield in protein extraction were obtained using O.OlM sódiurn ascorbate or O.OlM sodiurn metabisulfite. Some functional properties of the defatted sunflower flour and isolates (extracted in the absence and presence of 0.01M sodium ascor-bate or O.OlM sodium metabisulfite) were determined. proteimax 90 HG, a commercial soy protein isolate, was used for comparison purposes.The sunflower isolates exhibited maximurn and minimum solubility at pH abor ve 7.0 and between 4.0 and 6.0, respectively. Thesunflower p~otein isolates showed a higher whipping capacity and lower water and fat absorption than Proteimax 90 HG. The emulsifying and whipping properties of sunflower isolates Here not affected by the presence of O.OlM sodium ascorbate or O.OlM sodium metabisulfite. However,. an increase in the water and fat absoq~ tion was observed. Cookies were prepared with wheat flour containing 10% sun flower protein isolates, in order to evaluate the feasibility of their use in the baking industry. Cookies with desirable characteristics af taste and color were made employing the isolate obtained in the pre-sence of O.OlM sodium ascorbate

ASSUNTO(S)

girassol - analise plants sunflower plantas - proteinas

ACESSO AO ARTIGO

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