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| E. Ciências Agrárias - 7. Ciência e Tecnologia de Alimentos - 4. Ciência e Tecnologia de Alimentos |
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| EFFECT OF INTERACTION BETWEEN LIPOXYGENASE ENZYME, ASCORBIC ACID AND BENZOYL PEROXYDE IN THE WHEAT FLOUR COLOUR AND RHEOLOGICAL PROPERTIES. |
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| kelen de Castro Oliveira , Inar Alves de Castro e Roberto de Moraes Junqueira Junior |
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| 1- Depto.de Alimentos e Nutrição Experimental / FBA / Faculdade de Ciências Farmacêuticas / FCF /
Universidade de São Paulo / USP
, UNIVERSIDADE DE SÃO PAULO - USP |
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| The sensory quality of baked products mainly depends upon the genetic characteristics of wheat varieties and wheat flour extraction degree. The objective of this study was to evaluate the interaction of the oxidative compounds lipoxygenase enzymes (x1), benzoyl peroxide (x2) and ascorbic acid (x3) on the dough rheological and color characteristics in the wheat flour through the application of an “centroid-simplex” experimental design. Seven mixtures and a control were prepared with different proportions of the three compounds and added to wheat flour at 1%. P, L and W parameters were obtained from eight assays using a “Chopin” alveograph. Flour color characterized by rightness (Lc) and hue (b) was determined instrumentally using a HunterLab colorimeter and sensorially in a ranking test with 18 selected tasters. Of the six selected variables evaluated in this study ( P,L,W, Lc, b and sensory color) three regression models were fitted to the dependent variables P,L and Lc, showing non-significant lack of fit (p>0.114) and elevated determination coefficient (0.92,0.84 and 0.94, respectively). A mixture containing 270.00 mg of x1, 4.80 ppm of x2 and 325 ppm of x3 was obtained from the regression optimization and utilized for validating the models. The optimized mixture (Lc of 92.0 ± 0.13) was as white as the control (Lc of 92.1 ± 0.03). Resistance to extension of the gluten structure presented by the optimized mixture (P=108.5 ± 2.12) indicated a 22% increase in comparison to the control assay (P=89.0± 5.70), demonstrating the synergism in the oxidizing action of the lipoxygenase enzyme with the ascorbic acid. The strengthening of the gluten matrix associated with the bleaching effect of the flour obtained in this study through the model optimization will permit the use in greater proportion of different wheat varieties or flours with higher extraction levels to produce baked products without sensory quality losses.
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Instituição de fomento: FAPESP
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Trabalho de Iniciação Científica
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| Palavras-chave:
dough; rheology; lipoxygenase |
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Anais da 57ª Reunião Anual da SBPC - Fortaleza, CE - Julho/2005
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